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Organosilicon compounds have attracted considerable attention because of their special biological activities. Direct difunctionalization of unsaturated hydrocarbons with organosilicon reagents for the efficient construction of synthetically valuable silicon-functionalized compounds are featured with a high step and atom economy, which could form carbon-silicon/carbon-carbon bonds or carbon-silicon/carbon-hetero bonds in one step. This review summarizes the recent advances on this topic based on different unsaturated hydrocarbons along with typical examples and mechanisms.

It is still a challenge to construct single-atom level reduction and oxidation sites in single-component photocatalyst by manipulating coordination configuration for photocatalytic water splitting. Herein, the atomically dispersed asymmetric configuration of six-coordinated Co-S 2 O 4 (two exposed S atoms, two OH groups, and two Co─O─Zn bonds) suspending on ZnIn 2 S 4 nanosheets verified by combining experimental analysis with theoretical calculation, is applied into photocatalytic water splitting. The Co-S 2 O 4 site immobilized by Vs acts as oxidation sites to guide electrons transferring to neighboring independent S atom, achieving efficient separation of reduction and oxidation sites. It is worth mentioning that stabilized Co-S 2 O 4 configuration show dynamic structure evolution to highly active Co-S 1 O 4 configuration (one exposed S atom, one OH group, and three Co─O─Zn bonds) in reaction, which lowers energy barrier of transition state for H 2 O activization. Ultimately, the optimized photocatalyst exhibits excellent photocatalytic activity for water splitting (H 2 : 80.13 µmol g -1 h -1 , O 2 : 37.81 µmol g -1 h -1 ) and outstanding stability than that of multicomponent photocatalysts due to dynamic and reversible evolution between stable Co-S 2 O 4 configuration and active Co-S 1 O 4 configuration. This work demonstrates new cognitions on immobilized strategy through vacancy inducing, manipulating coordination configuration, and dynamic evolution mechanism of single-atom level catalytic site in photocatalytic water splitting., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

This study elucidates the mechanisms and principles governing chemoselectivity in synthesizing two distinct N-heterocycles, benzimidazole thiazine and benzothiazole imidazole, through BF 3 •OEt 2 -catalyzed cyclization reactions of propargyl alcohols with benzimidazole thiols. Employing density functional theory calculations, we highlight the crucial role of fluorine source in influencing chemoselectivity. In DCM, BF 3 , as the catalytic center, coordinates with propargyl alcohol's hydroxyl group to form a precursor. Conversely, in DMF, [BF 2 •DMF] + , formed from DMF and BF 3 •OEt 2 , acts as the catalytic center, activating the propargyl alcohol's hydroxyl group. The mechanisms in both solvents involve sequential steps: B-O bond formation, C-O bond cleavage, S-C bond formation, hydrogen atom transfer (HAT), cyclization, and deprotonation. A notable difference is the HAT process: in DCM, it follows a 1,5-HAT process, while in DMF, BF 4 - formation from DMF and BF 3 •OEt 2 provides a fluorine source and introduces steric hindrance, favoring a 1,6-HAT process and leading to unique chemoselectivity. This pioneering research showcases the impact of DMF on cyclization reactions, offering valuable insights for comprehending and designing reactions driven by fluorine sources. Crucially, our results propose an innovative reaction mechanism featuring lower potential energy surfaces, enhancing our understanding of the intricate interplay among reactants, catalysts, and solvents.

Purpose: Traumatic brain injury (TBI), currently a major global public health problem, imposes a significant economic burden on society and families. We aimed to quantify and predict the incidence and severity of TBI by analyzing its incidence, prevalence, and years lived with disability (YLDs). The epidemiological changes in TBI from 1990 to 2019 were described and updated to provide a reference for developing prevention, treatment, and incidence-reducing measures for TBI., Methods: A secondary analysis was performed on the incidence, prevalence, and YLDs of TBI by sex, age group, and region (n = 21,204 countries and territories) between 1990 and 2019 using the Global Burden of Diseases, Injuries, and Risk Factors Study 2019. Proportions in the age-standardized incidence rate due to underlying causes of TBI and proportions of minor and moderate or severe TBI were also reported., Results: In 2019, there were 27.16 million (95% uncertainty intervals (UI): 23.36 - 31.42) new cases of TBI worldwide, with age-standardized incidence and prevalence rates of 346 per 100,000 population (95% UI: 298-401) and 599 per 100,000 population (95% UI: 573-627), respectively. From 1990 to 2019, there were no significant trends in global age-standardized incidence (estimated annual percentage changes: -0.11%, 95% UI: -0.18% - -0.04%) or prevalence (estimated annual percentage changes: 0.01%, 95% UI: -0.04% - 0.06%). TBI caused 7.08 million (95% UI: 5.00 - 9.59) YLDs in 2019, with age-standardized rates of 86.5 per 100,000 population (95% UI: 61.1 - 117.2). In 2019, the countries with higher incidence rates were mainly distributed in Central Europe, Eastern Europe, and Australia. The 2019 global age-standardized incidence rate was higher in males than in females. The 2019 global incidence of moderate and severe TBI was 182.7 per 100,000 population, accounting for 52.8% of all TBI, with falls and road traffic injuries being the main causes in most regions., Conclusions: The incidence of moderate and severe TBI was slightly higher in 2019, and TBI still accounts for a significant portion of the global injury burden. The likelihood of moderate to severe TBI and the trend of major injury under each injury cause from 1990 to 2019 and the characteristics of injury mechanisms in each age group are presented, providing a basis for further research on injury causes in each age group and the future establishment of corresponding policies and protective measures., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Chinese Medical Association. Production and hosting by Elsevier B.V. All rights reserved.)

1,4-dioxane is a potential carcinogen in water and is difficult to deal with due to its robust cycloether bond and complete miscibility with water. To remove 1,4-dioxane in an economically viable and environmentally friendly way, a series of carbon aerogels were synthesized as adsorbents for 1,4-dioxane. The experiment results showed that adsorption performances were closely related to the preparation conditions of carbon aerogels, such as the molar ratio, heating rate, pyrolysis temperature and residence time, which were carefully controlled. Scanning electron microscope analysis revealed the presence of a three-dimensional porous network structure in carbon aerogels. Brunauer-Emmett-Teller analysis results demonstrated an increase in specific surface area (673.89 m 2 /g) and total pore volume after carbonization, with an increase in mesoporous porosity and a decrease in microporosity. When considering each variable individually, the highest specific surface area of prepared carbon aerogels was achieved at a pyrolysis temperature of 800 °C, a holding time of 1 h, and a heating rate of 2 °C/min. Under optimal experimental conditions, the adsorption removal of 1,4-dioxane by carbon aerogels exceeded 95%, following quasi-second-order kinetics and Langmuir isothermal adsorption isotherms, indicating that monolayer adsorption on the surface of carbon aerogels occurred. The maximum adsorption capacity obtained was 67.28 mg/g at a temperature of 318 K, which was attributed to the presence of a large proportion of mesopores and abundant micropores simultaneously in carbon aerogels. Furthermore, with the interference of chlorinated solvents such as trichloroethylene (TCE), the removal efficiency of 1,4-dioxane had no obvious inhibition effect. Regeneration experiments showed that after five continuous cycles, the carbon aerogels still kept a comparable adsorption capacity, which illustrates its potential application in 1,4-dioxane-polluted water purification.

Here, an Ir/Zn-cocatalyzed atroposelective [2+2+2] cycloaddition of 1,6-diynes and ynamines was developed, forging various functionalized C─N axially chiral indoles and pyrroles in generally good to excellent yields (up to 99%), excellent chemoselectivities, and high enantioselectivities (up to 98% enantiomeric excess) with wide substrate scope. This cocatalyzed strategy not only provided an alternative promising and reliable way for asymmetric alkyne [2+2+2] cyclotrimerization in an easy handle but also settled the issues of previous [Rh(COD) 2 ]BF 4 -catalyzed system on the construction of C─N axial chirality such as complex operations, limited substrate scope, and low efficiency. In addition, control experiments and theoretical calculations disclosed that Zn(OTf) 2 markedly reduced the barrier of migration insertion to significantly increase reaction efficiency, which was distinctly different from previous work on the Lewis acid for improving reaction yield through accelerating oxidative addition and reductive elimination.

A copper-catalyzed remote benzylic C-H functionalization strategy enabling 1,2-difunctionalization of alkenes with 2-methylbenzeneamides and nucleophiles, including alcohols, indoles, pyrroles, and the intrinsic amino groups, is reported, which is characterized by its redox-neutral conditions, exquisite site-selectivity, broad substrate scope, and wide utilizations of late-stage modifying bioactive molecules. This reaction proceeds through nitrogen-centered radical generation, hydrogen atom transfer, benzylic radical addition across the alkenes, single-electron oxidation, and carbocation electrophilic course cascades. While using external nucleophiles manipulates three-component alkene alkylalkoxylation and alkyl-heteroarylation with 2-methylbenzeneamides to access dialkyl ethers, 3-alkylindoles, and 3-alkylpyrroles, omitting the external nucleophiles results in two-component alkylamidation ([5+2] annulation) of alkenes with 2-methylbenzeneamides to benzo-[ f ][1,2]thiazepine 1,1-dioxides.

We have developed a new radical-mediated alkoxypolyhaloalkylation of styrenes with polychloroalkanes and alcohols for the facile synthesis of complex polyhaloalkanes. 4-Methoxybenzenediazonium tetrafluoroborate is a good radical initiator for this transformation. This protocol is well applied to the late-stage functionalization of complex molecules, including vitamin E, estrone and cholesterol derivatives.

We have disclosed a new radical-mediated decarboxylative C(sp 3 )-N cross-coupling of diacyl peroxides with nitrogen nucleophiles. The primary and secondary alkyl radicals derived from corresponding diacyl peroxides were generated by copper catalysis or by merging copper catalysis and photoredox catalysis, respectively. Various N -alkyl nitrogen nucleophiles, including indazoles, triazoles, indoles, purine, carbazole, anilines, and sulfonamide, were provided with a broad substrate scope and good functional group tolerance.

We have developed a new oxidative decarboxylation of cinnamic acids with 4-alkyl-1,4-dihydropyridines to construct C(sp3)-C(sp2) bonds in the presence of copper catalyst and dicumyl peroxide (DCP). A variety of internal alkenes have been obtained with mild conditions, broad substrate scope and excellent functional group tolerance. This method has significant potential for application by using inexpensive and stable cinnamic acids instead of alkenyl halides and nitro-olefins.

A general, ideal atom utilization electrochemical technology to enable alkene alkoxyhalogenation and organohalide dehalogenation in one pot is presented. This technology is highlighted by convergent strategy integrating several reactions, such as alkene alkoxyhalogenation, organohalide dehalogenation, and dehalogenation deuteration. Experimental data suggest that alkenes have the lowest oxidation potential, which lead to anodic conversion of the C═C bond to the radical cation intermediates, and cathodic transformations of organohalides, including alkyl and aryl halides, as the nucleophilic halogen sources.

A new external oxidant-free electrochemical dehydrogenative cross-coupling of xanthenes and ketones for the preparation of functionalized 9-alkyl-9H-xanthenes was developed. This method enables the formation of a new C(sp 3 )-C(sp 3 ) bond through release of H 2 as the major byproduct at room temperature, and features mild conditions, high atom economy, excellent functional-group tolerance, scalability and facile applications in pharmaceutical chemistry.

A simple and practical method for the synthesis of phosphoryl-substituted indolo[2,1-a]isoquinolin-6(5H)-ones and benzimidazo[2,1-a]isoquinolin-6(5H)-ones through manganese(iii)-promoted tandem phosphinoylation/cyclization of 2-arylindoles or 2-arylbenzimidazoles with disubstituted phosphine oxides was developed. In this transformation, new C-P bond and C-C bond were constructed simultaneously under silver-free conditions, exhibiting a broad substrate scope. It was noted that not only diarylphosphine oxides but also dialkyl and arylalkyl-phosphine oxides were compatible with the conditions.

Objective: This study set out to explore the regulatory mechanism of miR-130a-5p in cisplatin (DDP)-resistant gastric cancer (GC) cells., Materials and Methods: Forty cases of GC and paracancerous tissues were collected, and the miR-130a-5p and CCL22 levels were detected by qRT-PCR. DDP-resistant cell lines of GC cells were established. Cell viability, invasion, and apoptosis were measured by CCK-8, Transwell, and flow cytometry, respectively. The relationship between miR-130a-5p and CCL22 was verified by dual-luciferase reporter enzyme, and the protein levels of caspase-3, bax, bcl-2, and CCL22 were determined by Western blot., Results: miR-130a-5p was low expressed in GC tissues and cells, while CCL22 showed marked negative correlation, and the area under the curve (AUC) for diagnosing GC was not less than 0.850. Up-regulating miR-130a-5p or knocking down CCL22 expression can inhibit the proliferation and invasion of GC cells and promote their apoptosis, reverse the resistance of NCI-N87/DDP to DDP, and also enhance the chemosensitivity of GC cells. Dual-luciferase reporter enzyme identified that there was a targeted relationship between miR-130a-5p and CCL22. At the same time, miR-130a-5p and CCL22 were up-regulated or down-regulated, and the malignant proliferation, invasion, apoptosis, and DDP chemotherapy resistance of the cells had no difference compared with miR-NC with transfection-unrelated sequences., Conclusion: Up-regulating miR-130a-5p can enhance the sensitivity of DDP-resistant GC cells to chemotherapy and regulate their biological function by targeted inhibition of CCL22., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Fang et al.)

A copper-catalyzed C-H [3 + 2] annulation of N-substituted anilines with α-carbonyl alkyl bromides for the synthesis of 3,3'-disubstituted oxindoles is developed. Tandem C-H cycloamidation reactions of various α-carbonyl alkyl bromide derivatives including tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkanes, with N-aryl or alkyl substituted anilines, can be performed using this system, affording a vast array of valuable 3,3'-disubstituted oxindoles in moderate to good yields.

We here describe a new, selective indium-promoted silver-mediated intermolecular oxidative 1,4-alkylarylation of 1,3-dienes with α-carbonyl alkyl bromides and N-heterocycles for producing functionalized N-heterocycles, which is characterized by its exquisitely controllable regio-/stereo-selectivity and excellent tolerance of functional groups. Mechanistically, the formation of the carbonyl-coordinated η 3 -allyl-In complex radical intermediate is the key factor for successfully achieving regio- and stereo-selectivity toward 1,4-difunctionalization and (E)-isomers.

The In(OTf) 3 -promoted three-component photoredox alkylarylation of styrenes with alkyl NHP esters and arenes to access alkylated arene derivatives through C-C bond cleavage and C-H functionalization is reported. By utilizing visible-light photoredox catalysis, alkyl N-hydroxyphthalimide esters serving as alkyl carbon-centered radicals and a wide range of arenes (e.g., indoles, pyrrole, and electron-rich arenes) as nucleophiles were used to enable the introduction of various alkyl groups and aryl groups across the C[double bond, length as m-dash]C bonds with excellent selectivity and functional group tolerance.

A new silver-mediated 1,2-alkylesterification of alkenes with nitriles and acids promoted by a catalytic amount of nickel catalyst for producing acyloxylated nitriles has been developed via a C(sp 3 )-H functionalization process. By employing the NiI 2 and Ag 2 CO 3 catalytic systems, the method features broad substrate scope with respect to carboxylic acids, including linear alkyl acids, cyclic acids, aryl acids and amino acids.

Novel adsorbent, diethylenetriamine-grafted Spirodela polyrhiza (DSP), was synthesized via modifying natural S. polyrhiza (SP) with diethylenetriamine by cross-linking with epichlorohydrin and applied to adsorb Ni 2+ and Pb 2+ from water. The effecting parameters on adsorption of Ni 2+ and Pb 2+ such as adsorbent dosage, pH, contact time, temperature, and initial concentration were studied through equilibrium experiments. The adsorption of Ni 2+ and Pb 2+ followed the pseudo-second-order model and the Langmuir isotherm adsorption model. The study discusses thermodynamic parameters, including changes in Gibbs free energy, entropy, and enthalpy, for the adsorption of Ni 2+ and Pb 2+ on DSP, and revealed that the adsorption process was spontaneous and exothermic under natural conditions. The maximum Ni 2+ and Pb 2+ adsorption capacities of DSP were 33.02 and 36.50 mg/g, respectively. The newly prepared materials were characterized through scanning electron microscopy (SEM), mapping analysis, and zeta potential analysis. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicated that functional groups (-OH and N-H) were involved in Ni 2+ and Pb 2+ adsorption. Notably, DSP can be easily regenerated and reused for multiple cycles. Therefore, DSP is a promising adsorbent for effective Ni 2+ and Pb 2+ removal.

A new, general silver-catalyzed oxidative 1,2-alkyletherification of unactivated olefinic ketones with primary, secondary and tertiary α-bromoalkyl carbonyls promoted by tert-butyl hydroperoxide (TBHP) and Et 3 N has been developed. Through the cooperative action of Ag 2 O, TBHP and Et 3 N, the reaction enables the construction of highly valuable quaternary-carbon-possessing 2,3-dihydrofuran frameworks using a concomitant intramolecular annulation strategy.

A new, general copper-catalyzed oxidative tandem [4+2] cycloaddition of α-( N -arylamino) carbonyl compounds with aryl alkenes to produce highly substituted quinolines has been developed, which allows the formation of three new C-C bonds through a sequence of multiple C-H functionalizations, annulation, and [1,2]-aryl shifts.

A new, practical directed anodic C-H sulfonylation of N,N-disubstituted anilines with sodium sulfinates for producing o- or p-amino arylsulfones and diarylsulfones is described. Employing the anodic strategy, the reaction proceeds efficiently under mild (room temperature) and transition-metal- and chemical oxidant-free conditions, and enables the formation of C-S bonds via directed activation of ortho- or para-C-H bond to the amino group with broad substrate scope and excellent site selectivity.

By a simple and convenient method of using epichlorohydrin as linkages, a novel Alternanthera philoxeroides (AP) derivative modified with diethylenetriamine (DAP) was synthesized, which can remove copper(II) ions (Cu(II)) in the water environment efficiently. The adsorption capacity of DAP for Cu(II) under various factors was measured using ultraviolet spectrophotometer. The adsorption capacity and removal ratio were 19.33 mg/g and 95.57% at pH 5.5 and 298 K. The kinetic and equilibrium study shows that pseudo-second-order kinetic (R 2 = 0.9964) and Langmuir isotherm models (R 2 > 0.982) could properly describe DAP adsorption behaviors, and thermodynamic parameters indicate a spontaneous endothermic process (ΔG = - 3.6636 kJ/mol). The combined results of SEM, XRD, FTIR, and XPS analyses reveal that the dominant contribution for enhancement in Cu(II) adsorption is made by the formation of an amino group. And the adsorption mechanism is mainly the complexation reaction. The adsorption efficiency of DAP remained above 72.06% after 6 cycles of adsorption-desorption, which indicated that DAP has good regenerability and stability. All the results suggest that DAP could serve as promising adsorbents for Cu(II) pollution minimization.

A new anode strategy for accessing xanthen-9-azoles via an electrochemical C(sp 3 )-H/N-H cross-coupling of xanthenes with azoles is described. This reaction proceeds efficiently with a broad scope of both xanthenes and N-H-free azoles under metal- and additional oxidant-free conditions and represents a new access to direct incorporation of important N-heterocycle units into the resulting xanthenes.

A simple three-component 1,2-bromoesterification of alkenes with acids and N-bromosuccinimide under electrochemical oxidative conditions is described. This transformation enables the construction of β-bromoalkyl esters via oxidative C-Br/C-O difunctionalization, where a variety of alkenes, including styrenes and cycloolefins, were well tolerated to react efficiently with a wide range of acids, such as aromatic acids, aliphatic acids, and amino acids.

A highly para-selective amination of anilines with phenothiazines for producing various functionalized 10-aryl-10H-phenothiazines is reported. The oxidative amination reaction proceeds electrochemically at room temperature, thereby avoiding the use of metals and oxidizing reagents with excellent functional group tolerance and broad substrate scope.

The functionalization of unactivated C(sp 3 )─H bonds represents one of the most powerful and most atom-economical tools for the formation of new carbon-based chemical bonds in synthesis. Although cross-dehydrogenative coupling reactions of two distinct C─H bonds for the formation of carbon-carbon bonds have been well investigated, controlled functionalizations of two or more different C(sp 3 )─H bonds across a functional group or a molecule (e.g., an alkene or alkyne) in a single reaction remain challenging. Here, we present a three-component dialkylation of alkenes with common alkanes and 1,3-dicarbonyl compounds via synergistic photoredox catalysis and iron catalysis for the synthesis of two functionalized 1,3-dicarbonyl compounds. Mechanistic studies suggest that the photoredox catalysis serves as a promotion system to allow the dialkylation to proceed under mild conditions by reducing the oxidation and reduction potentials of the iron intermediates and the reaction partners.

A new copper-catalyzed three-component oxidative 1,2-trifluoromethylarylation of styrenes with NaSO2CF3 and indoles involving aryl C-H bond functionalization is described. This reaction is initiated by single electron transfer upon utilizing TBPB as an oxidant, thus enabling introduction of a CF3 group and an aryl group into the C[double bond, length as m-dash]C bond of alkenes in a single step. This method represents a highly atom and step-economical access to various CF3-substituted 1,1-diarylalkane derivatives in moderate to good yields with good functional group compatibility.

Functionalization of alkenes has been well investigated by chemists, thus it has been extensively applied in organic synthesis and industries. In the past few decades, transition-metal, such as palladium, rhodium, gold, iridium, copper and iron, catalyzed functionalization reactions of alkenes have been significantly developed and played vital roles in synthesis. The difunctionalization of alkenes are appealing as an important alternative to the traditional approaches for the construction of useful carbon centers, particularly carbon quaternary centers, which commonly existed as structural motifs in numerous natural products, pharmaceuticals, and biologically active molecules. This account will summarize our recent advances in the intermolecular difunctionalization of alkenes, and also highlight the scope and limitations as well as the mechanisms of these difunctionalization reactions. In general, in this account the difunctionalization of alkenes starting from dicarbofunctionalization will be discussed. Then carboheterofunctionalization of alkenes will be intensively reviewed, and diheterofunctionalization will also be highlighted., (© 2019 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A new ruthenium(ii)-catalyzed electrooxidative [4+2] annulation of primary benzylic alcohols with internal alkynes is described, which enables benzylic alcohols as weakly directing group precursors to access isocoumarins via multiple C-H functionalization. The reaction works well with a broad substrate scope, tolerates a wide range of functional groups, and incorporates practically the isocoumarin unit into diverse bioactive molecules. Mechanistic studies indicate that activation of aryl C(sp 2 )-H bonds is achieved through the generation of the active benzoyloxy-Ru(ii) intermediates via oxidation of benzylic alcohols using an electrooxidative Ru(ii) catalyst.

A new, one-step rhodium(III)-catalyzed annulation of 4-arylbut-3-yn-1-amines with internal alkynes through C-H functionalization is reported. This reaction allows the formation of three new chemical bonds, including two C-C bonds and one C-N band, thus selectively assembling various spiro[indene-1,2'-pyrrolidine]s with excellent functional group compatibility, high atom-economy, and step-efficiency.

A new copper-catalyzed oxidative three-component intermolecular 1,2-alkylarylation of styrenes with ethers and indoles is disclosed. This method utilizes TBPB as an oxidant to efficiently construct C(sp 3 )-C(sp 3 ) and C(sp 3 )-C(sp 2 ) bonds in one step through probable radical and electrophilic alkylation processes, respectively, and a variety of functional groups are well tolerated.

A simple protocol for the three-component intermolecular alkylesterification of styrenes with toluenes and peroxyesters using a copper catalyst is described. A variety of ester-containing complex compounds were synthesized with excellent functional group tolerance and step efficiency. Employing the combination of carboxylic acids and di- tert-butyl peroxide (DTBP) oxidant instead of peroxyesters also gave similar results. In this transformation, aromatic acids, aliphatic acids, and amino acids were suitable substrates.

For straightforward access to various substituted 1,1-diarylalkanes a photoredox-catalyzed and copper-promoted 1,2-alkylarylation reaction of styrenes has been developed, which uses α-carbonyl alkyl bromides and N,N-disubstituted anilines as functionalization reagents. In this radical difunctionalization reaction, α-carbonyl alkyl bromides, including primary-, secondary- and tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkane were transformed to the corresponding 1,1-diarylalkanes in moderate to good yields at room temperature. Notably, this transformation provided a new route for the C-H alkylation of N,N-disubstituted anilines with high para-selectivity beyond the typical Friedel-Crafts alkylation.

A novel cascade annulation of 1,7-diynes with water has been developed for the synthesis of furo[3,4- c]quinolin-4(5 H)-one skeletons with high atom- and step-economy. The transformation was enabled by a palladium catalyst in the presence of copper salt as the promoter, involving the formation of one C-C bond and two C-O bonds. Moreover, the reaction exhibits good tolerance of functional groups and broad substrate scope. Notably, the control experiments support the incorporation of the new oxygen atom from water.

A new, three-component 1,2-alkylamination of styrenes with alkyl N-hydroxyphthalimide (NHP) esters and amines by Lewis acid and visible-light photoredox cooperative catalysis is described. This reaction employs alkyl NHP esters as general alkylation reagents to accomplish the 1,2-alkylamination of alkenes in high efficiency and with excellent functional groups tolerance, significantly enhancing the synthetic potential of 1,2-alkylaminations of alkenes for accessing complex functionalized amines.

An indium-promoted intermolecular oxidative 1,2-alkylarylation of alkenes with alkyl nitriles and N-heteroarenes enabled by C(sp3)-H/C(sp2)-H functionalization is presented. This oxidative radical strategy allows the formation of two new C-C bonds through transformations of two different C-H bonds across the alkenes in a controlled single-step manner, and offers a general, highly atom-economic route for the production of new functionalized N-heteroarenes, including indoles, pyrrolo[2,3-b]pyridine, pyrrolo[3,2,1-ij]quinolone and pyrroles.

A new palladium-catalyzed reductive [5+1] cycloaddition of 3-acetoxy-1,4-enynes with CO, enabled by hydrosilanes, has been developed for delivering valuable functionalized phenols. This methodology employs hydrosilanes as the external reagent to facilitate the [5+1] carbonylative benzannulation. The reaction is a conceptually and mechanistically novel carbonylative cycloaddition route for the construction of substituted phenols, through the formation of four new chemical bonds, with excellent functional-group tolerance., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

α-Carbonyl alkyl bromides are powerful reactive species for the formation of carbon-carbon bonds. Strategies relying on intermolecular C-H functionalization and cross-coupling reactions, also referred to as intramolecular cyclization, have been employed for the construction of alkenes, alkanes, ketones, and other natural-product-like ring compounds from simple alkynes, alkenes, and 1,n-enynes. In view of the importance of these α-carbonyl alkyl bromides, especially the difluoro carbonyl alkyl bromides, many researchers have focused their efforts to develop facile and mild synthetic methods for compounds with important biological activities. This review aims to briefly discuss the latest developments in the transformation of α-carbonyl alkyl bromides with emphasis on the related reaction mechanisms., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Straightforward access to various substituted naphthalenones by copper-catalyzed [4 + 2] annulation cascades of 2-bromo-1-arylpropan-1-ones with terminal alkynes is presented. Employing a Cu(MeCN) 4 PF 4 catalyst and 1,10-phenanthroline (1,10-Phen) ligand enables the formation of three new C-C bonds in a single reaction via [4 + 2] annulation of a 2-bromo-1-arylpropan-1-one with an alkyne followed by α-alkylation with the other 2-bromo-1-arylpropan-1-one with excellent functional group tolerance and step efficiency.

A copper-catalyzed oxidative radical strategy to avoid the use of the highly expensive noble metal/ligand catalytic systems is described, which allows selective activation of dual chemical bonds around the Si-atom center relying on the nature of alkylsilanes. While for tertiary silanes selective functionalization of Si-H/silyl C(sp 3 )-H bonds in intermolecular oxidative annulation cascades with N-(2-(ethynyl)aryl)acrylamides toward silino[3,4-c]quinolin-5(3H)-ones, when using secondary silanes and HSi(TMS) 3 , dual Si-H bonds or Si-H/Si-Si bonds are selectively cleaved leading to 4H-silolo[3,4-c]quinolin-4-ones.

A Mn-promoted intermolecular oxidative radical heteroannulation of N-(2-cyanoaryl)-acrylamides and tertiary silanes has been described, which provides an efficient route to produce silicon/nitrogen heterocycles, sila-analogues of the known carbon-based structural motifs prevalent in bioactive natural products, pharmaceuticals and materials. The reaction enables Si-incorporation by controlling accurately several chemical bond cleavage and formation processes. Moreover, this reaction represents a new one-step construction of 1,3-azasiline-fused quinolinones that was achieved via silyl C(sp 3 )-H functionalization using an oxidative radical strategy.

A novel tandem annulation of N-(o-ethynylaryl)acrylamides, with CH 2 Cl 2 as a one-carbon unit, for the divergent synthesis of cyclopenta[c]quinolin-4(5H)-ones and benzo[j]phenanthridin-6(5H)-ones, which relies on the substitution effect of the 2 position of the acrylamide moiety, is described. Promoted by the visible-light photoredox catalysis, this reaction allows the formation of multiple chemical bonds through multiple C-Cl/C-H functionalization and [2 + 2 + 1] annulation cascades.

A new palladium-catalyzed dearomatizative [2 + 2 + 1] carboannulation of 1,7-enynes with aryl diazonium salts and H 2 O is presented. The reaction enables the construction of spirocyclohexadienone-fused cyclopenta[c]quinolin-4(5H)-ones through a sequence of Heck-type addition, 6-exo-dig cyclization, ipso-cyclization, dearomatization and hydrolysis.

The first iron-catalyzed 1,2-difunctionalization of styrenes and conjugated alkenes with silanes and either N or C, using an oxidative radical strategy, is described. Employing FeCl 2 and di-tert-butyl peroxide allows divergent alkene 1,2-difunctionalizations, including 1,2-aminosilylation, 1,2-arylsilylation, and 1,2-alkylsilylation, which rely on a wide range of nucleophiles, namely, amines, amides, indoles, pyrroles, and 1,3-dicarbonyls, thus providing a powerful platform for producing diverse silicon-containing alkanes., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A new divergent intermolecular cascade annulation reaction of N-(arylsulfonyl)acrylamides with dual alkyl C(sp 3 )-H bonds for producing two types of five-membered rings, indanes and pyrrolidin-2-ones, is described. By using cycloalkanes and common alkanes as a one-carbon unit, an intermolecular [4+1] cascade carboannulation of N-(arylsulfonyl)acrylamides was achieved via a sequence of three C-H bond functionalization/aryl migration/desulfonylation that enables the formation of three C-C bonds and one N-H bond. When the one-carbon unit was changed to cycloalkyl ethers, the alternative intermolecular [4+1] cascade heteroannulation reaction occurred and allowed the construction of two C-C bonds and one C-N bond through dual C-H bond functionalization, aryl migration and desulfonylation cascades.

Difunctionalization of alkenes has become a powerful tool for quickly increasing molecular complexity in synthesis. Despite significant progress in the area of alkene difunctionalization involving the incorporation of a nitrogen atom across the C-C double bonds, approaches for the direct 1,2-carboamination of alkenes to produce linear N-containing molecules are scarce and remain a formidable challenge. Here we describe a radical-mediated oxidative intermolecular 1,2-alkylamination of alkenes with alkyl nitriles and amines involving C(sp 3 )-H oxidative functionalization catalysed by a combination of Ag 2 CO 3 with iron Lewis acids. This three-component alkene 1,2-alkylamination method is initiated by the C(sp 3 )-H oxidative radical functionalization, which enables one-step formation of two new chemical bonds, a C-C bond and a C-N bond, to selectively produce γ-amino alkyl nitriles.

A novel copper-promoted [2+2+2] annulation of 1,n-enynes with azobis(alkyl nitrile)s and H 2 O for the synthesis of diverse 7,8-dihydrophenanthridine-6,9(5H,6aH)-diones and fluorene is described. The reaction proceeds via the decomposition of azobis(alkyl nitrile)s into the cyanoalkyl radicals as the two-carbon units and offers a new efficient tool for the one-step formation of four new chemical bonds.

A new copper-catalyzed tandem C-H oxidative radical functionalization and annulation of aniline-linked 1,7-enynes with alkyl nitriles or acetone is described. This reaction allows the selective construction of 1H-cyclopenta[c]quinolines and benzo[j]phenanthridin-6(5H)-ones which rely on the substitution effect at the 2-position of the acrylamide moiety. The mechanism involving a 1,5-hydride shift process is proposed according to the control deuterium-labeled experiment.