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SmI2-mediated desymmetrization of a meso-cyclic 1,3-dione pinacol coupling is described. The reaction proceeds with high stereoselectivity to provide fused carbocyclic compounds with three contiguous stereogenic centers featuring an all-carbon quaternary center and a cis-1,2-diol moiety.

A synthetic strategy for the formation of C(sp3)-N bonds, particularly through a copper-catalyzed oxidative cross-coupling, is rare. Herein, we report a novel synthetic approach for the preparation of tertiary sulfonamides via copper-catalyzed intra- and intermolecular oxidative C(sp3)-N cross-coupling reactions. This method allows the utilization of the readily available C(sp3)-based pinacol boronate as a substrate and the tolerance of a wide range of functional groups under mild reaction conditions. The success of this strategy relies on the unprecedented additive effects of silanol and NaIO4.

Gallium hydrides stabilised by primary and secondary amines are scarce due to their propensity to eliminate dihydrogen. Consequently, their reactivity has received limited attention. The synthesis of two novel gallium hydride complexes HGa(THF)[ON(H)O] and H2 Ga[μ2 -ON(H)O]Ga[ON(H)O] ([ON(H)O]2- =N,N-bis(3,5-di-tert-butyl-2-phenoxy)amine) is described and their reactivity towards aldehydes and ketones is explored. These reactions afford alkoxide-bridged dimers through 1,2-hydrogallation reactions. The gallium hydrides can be regenerated through Ga-O/B-H metathesis from the reaction of such dimers with pinacol borane (HBpin) or 9-borabicyclo[3.3.1]nonane (9-BBN). These observations allowed us to target the catalytic reduction of carbonyl substrates (aldehydes, ketones and carbon dioxide) with low catalyst loadings at room temperature.

Bicyclic hydrocarbons, and bicyclo[1.1.1]pentanes (BCPs) in particular, are playing an emerging role as saturated bioisosteres in pharmaceutical, agrochemical and materials chemistry. Taking advantage of strain-release strategies, prior synthetic studies have featured the synthesis of bridgehead-substituted (C1, C3) BCPs from [1.1.1]propellane. Here, we describe an approach to access multisubstituted BCPs via intramolecular cyclization. In addition to C1,C3-disubstituted BCPs, this method also enables the construction of underexplored multisubstituted (C1, C2 and C3) BCPs from readily accessible cyclobutanones. The broad generality of this method has also been examined through the synthesis of a variety of other caged bicyclic molecules, ranging from [2.1.1] to [3.2.1] scaffolds. The modularity afforded by the pendant bridgehead boron pinacol esters generated during the cyclization reaction has been demonstrated through several downstream functionalizations, highlighting the ability of this approach to enable the programmed and divergent synthesis of multisubstituted bicyclic hydrocarbons. Bicyclic hydrocarbons, and bicyclo[1.1.1]pentanes in particular, are playing an emerging role as saturated bioisosteres in pharmaceutical, agrochemical and materials intramolecular coupling approach has been developed for the modular construction of underexplored multisubstituted strained bicyclic hydrocarbons, ranging from [1.1.1] to [3.2.1] scaffolds.

Mayenite (12CaO·7Al2O3) is a mesoporous calcium aluminum oxide, with a characteristic crystalline structure. The framework of mayenite is composed of interconnected cages with a positive electric charge per unit cell that includes two molecules [Ca24Al28O64]4+, and the remaining two oxide ions O2−, often labelled “free oxygen”, are trapped in the cages defined by the framework. Starting from mayenite structure several derivatives have been prepared through advanced synthetic protocols by free oxygen substitution with various anions. Mayenite and its derivates have been intensively investigated in many applications which include catalysis (oxidation and reduction, ammonia synthesis, pinacol coupling), environmental sensors and CO2 sorbent materials. In this review, we summarize our recent results on the main applications of mayenite and its derivatives.

Nortopsentin D is part of a class of bis(indole) alkaloids known for their biological activity, including inhibitory activity in tumoral cells and antifungal activity. Herein we describe the first total synthesis of nortopsentin D, in which amidine and dione undergo a pivotal condensation and subsequent cyclization via a pinacol-like rearrangement. This synthesis represents a unique strategy for the formation of 5,5-disubstituted (4H)-imidazol-4-one containing natural products, many of which have yet to succumb to total synthesis.

An unprecedented visible-light-induced transition-metal-free alkynylation of alkyl pinacol boronates has been demonstrated with alkynyl phenylsulfones as the alkynylation reagents and 4CzIPN as the...

The conversion of silyloxyarenes to boronic acid pinacol esters via nickel catalysis is described. In contrast to other borylation protocols of inert C-O bonds, the method is competent in activating the carbon-oxygen bond of silyloxyarenes in isolated aromatic systems lacking a directing group. The catalytic functionalization of benzyl silyl ethers was also achieved under these conditions. Sequential cross-coupling reactions were achieved by leveraging the orthogonal reactivity of silyloxyarenes, which could then be functionalized subsequently.

Isopropenyl boronic acid pinacol ester (IPBpin) was used as a comonomer in radical polymerization with a wide range of common vinyl monomers for elucidation of the monomer character and syntheses of conventionally inaccessible copolymers via the replacement of the boron pendant. The study revealed that the boron-containing monomer is categorized into an electron-rich conjugated monomer, which was well consistent with the results of density functional theory (DFT)-based investigation. One of the thus obtained copolymers, the IPBpin-styrene copolymer, was successfully transformed into an α-methyl vinyl alcohol (MVA)-styrene counterpart via oxidation of the boron pendant. The copolymer cannot be synthesized even with the acetyl-protected monomer instead of IPBpin due to poor copolymerization ability based on the nonconjugated character.

In this work, various types of chain-transfer agents (CTAs) were investigated in the reversible addition-fragmentation chain-transfer (RAFT) polymerization of isopropenyl boronate pinacol ester (IPBpin) toward not only precise synthesis of poly(IPBpin) but also elucidation of its feature as a monomer. CTAs suitable for conjugated monomers were found to be more compatible than those for nonconjugated monomers, likely due to the moderate stabilization of the growing radical by boron. This trend was supported by density functional theory-based calculations for energy balance between the growing IPBpin radical and the chain-transfer species to the CTA. The CTA-derived group at the ω-terminus of the obtained poly(IPBpin) was quantitatively converted into olefin under cobalt catalysis leading to improved stability, enabling evaluation of its well-defined structure by MALDI-TOF-MS and its thermal properties by DSC. The precise synthesis of poly(alkenyl boronate)s was achieved through RAFT polymerization of isopropenyl boronate pinacol ester (IPBpin) and subsequent terminal olefination by cobalt catalysis. Experimental and computational investigation on the compatibility of IPBpin with chain transfer agents revealed its conjugated-monomer type behavior that is ascribed to empty p-orbital of boron. Terminal olefination in post-polymerization reaction improved the stability of resulting polymers, enabling the analysis for molecular structure of poly(IPBpin) by MALDI-TOF-MS spectroscopy as well as thermal properties by DSC.

A continuous-flow photo-bromination reaction on benzyl and phenyl groups was conducted using N-bromosuccinimide as the bromine source inside a preparatory-scale glass plate reactor. This flow reactor system was capable of independently controlling light intensity, wavelength, and reaction temperature, hence exerting an exceptional level of control over the reaction. A short optimisation study for the synthesis of 2-bromomethyl-4-trifluoromethoxyphenylboronic acid pinacol ester resulted in best conditions of 20°C and 10 min residence time using an LED (light-emitting diode) array at 405 nm and acetonitrile as the solvent. The present study evaluates the potential for this easy-to-handle bromination system to be scaled up for chemical manufacture inside a continuous-flow glass plate reactor. The combination with an in-line continuous flow liquid–liquid extraction and separation system, using a membrane separator, demonstrates the potential for continuous flow reaction with purification in an integrated multi-stage operation with minimal manual handling in between.

We present an efficient and versatile visible light-driven methodology to transform aryl aldehydes and ketones chemoselectively either to alcohols or to pinacol products with CdSe/CdS core/shell quantum dots as photocatalysts. Thiophenols were used as proton and hydrogen atom donors and as hole traps for the excited quantum dots (QDs) in these reactions. The two products can be switched from one to the other simply by changing the amount of thiophenol in the reaction system. The core/shell QD catalysts are highly efficient with a turn over number (TON) larger than 4 X 10(4) and 4 X 10(5) for the reduction to alcohol and pinacol formation, respectively, and are very stable so that they can be recycled for at least 10 times in the reactions without significant loss of catalytic activity. The additional advantages of this method include good functional group tolerance, mild reaction conditions, the allowance of selectively reducing aldehydes in the presence of ketones, and easiness for large scale reactions. Reaction mechanisms were studied by quenching experiments and a radical capture experiment, and the reasons for the switchover of the reaction pathways upon the change of reaction conditions are provided.

Solid-state lithium metal batteries (LMBs) assembled with polymer electrolytes (PEs) and lithium metal anodes are promising batteries owing to their enhanced safety and ultrahigh theoretical energy densities. Nevertheless, polymer electrolytes (PEs) suffer from low ionic conductivities, low lithium-ion transference numbers (LITNs) and high flammability. To address these issues, a novel nonflammable single-ion conducting polymer electrolyte (AEP) with ultrahigh ionic conductivity, unity LITN, excellent flame retardance and high flexibility has been developed. Allylboronic acid pinacol ester (AAPE) is incorporated into the 3D cross-linking network of AEP to act as the anion acceptor that traps the anions, improving the LITN to 0.79. AEP possesses an ultrahigh ionic conductivity of 2.52 mS cm−1 at 25 °C. AEP cannot be ignited by flame. AEP can construct robust LiF-rich SEIs on lithium metal anodes and effectively suppress dendrite growth. LiFePO4 cells assembled with AEP demonstrate excellent rate capacity (specific capacity of 112.4 mA h g−1 at 5C rate) and long-term cycling stability (93.2% capacity retention after 500 cycles). This work provides a promising approach to prepare new PEs for high-safety, high-stability and high-energy LMBs.

The Petasis reaction using (1S,2R)-1-amino-2-indanol as the substrate and an activator to construct α- and β-butadienyl amines in optically pure forms was realized, which are otherwise difficult to prepare. The reactions feature a metal-free nature, broad substrate scope, complete regioselectivities (γ-selectivity of pinacol homoallenyl- and isoprenylboronates), and high to excellent chirality induction (up to >20 : 1 dr). The favored nucleophilic addition across the Si-face of the imine intermediate was explained using DFT calculations of the six-membered chair-like transition state.

A convenient, pyridine-boryl radical-mediated pinacol coupling of diaryl ketones is developed. In contrast to the conventional pinacol coupling that requires sensitive reducing metal, the current method employs a stable diboron reagent and pyridine Lewis base catalyst for the generation of a ketyl radical. The newly developed process is operationally simple, and the desired diols are produced with excellent efficiency in up to 99% yield within 1 hour. The superior reactivity of diaryl ketone was observed over monoaryl carbonyl compounds and analyzed by DFT calculations, which suggests the necessity of both aromatic rings for the maximum stabilization of the transition states.

A cascade Suzuki–Miyaura cross-coupling giving rise to 9,10-dihydrophenanthrenes has been developed. Using biaryls with unsymmetrical substitution-pattern full site-selectivity was observed. Furthermore, this cross-coupling of an alkyl 1,2-bisboronic pinacol ester proceeds through the challenging coupling of a secondary boronate with complete stereoretention., Chemical Communications, 57 (32), ISSN:1359-7345, ISSN:1364-548X

In this study, we report the synthesis and phase behaviour of statistical p(N-isopropylacrylamide-co-2-acrylamidephenylboronic acid) P(NIPAM-co-2-AAPBA) copolymers. They were obtained via free radical copolymerization of NIPAM and the pinacol ester of 2-acrylamidephenylboronic acid. The influence of copolymer composition on the demixing/mixing temperature was investigated by means of UV/Vis spectrometry, DLS, DSC, and 1H NMR spectroscopy. The turbidity experiments revealed the gradual increase of the cloud point with the increase of 2-AAPBA content in the copolymer up to 37 °C at 30 mol%. The copolymer with 45 mol% did not display any transition. For copolymers displaying the cloud point, the hysteresis in the demixing/mixing temperature was observed. Transmittance measurements, DLS, and 1H NMR spectroscopy demonstrated that the phase transition was sharp upon heating, whereas the phase transition of the copolymer upon a decrease of temperature occurred in a much wider temperature range. Moreover, the NIPAM copolymer with 5 mol% 2-AAPBA content displayed 5 °C hysteresis, whereas for the copolymer containing 30 mol% 2-AAPBA it reached 25 °C. Actually, nanoparticles were formed from the copolymer with 30 mol% of 2-AAPBA above the cloud point, which were stable upon cooling to 5 °C showing the potential for drug delivery applications. Raman spectroscopy applied for the analysis of an aqueous solution of NIPAM copolymer with 15 mol% content heated over the cloud point revealed the appearance of a vibrational band at 753 cm−1 characteristic of boroxine, i.e., boronic acid anhydride, the formation of which explains the broadening of the hysteresis. The detailed analysis of experimental data supported with DFT calculations evidenced the presence of other vibrational bands of 2-AAPBA anhydride (780, 957 and 999 cm−1). This is the first report of boroxine formation upon the phase transition of boronic acid-based thermoresponsive copolymers.

Suzuki-Miyaura catalyst-transfer condensation polymerization (CTCP) of fluorene-thiophene biaryl monomers was investigated for the synthesis of well-defined poly(fluorene-alt-thiophene). Model reactions of α,ω-dibromo(fluorene-thiophene) with arylboronic acid esters showed that t-Bu3P Pd and di-tert-butyl(4-dimethylaminophenyl)phosphine (AmPhos) Pd catalysts undergo intramolecular catalyst transfer from fluorene to thiophene, irrespective of the use of phenyl- or thiopheneboronate. Based on the results of the model reactions, PinB-fluorene-thiophene-Br (PinB = pinacol boronate) monomers were synthesized. The polymerization of monomer containing the 3-octyl-5-bromothiophene-2-yl unit was accompanied with disproportionation, whereas the polymerization of monomer containing the 4-octyl-5-bromothiophene-2-yl unit with an AmPhos Pd initiator proceeded according to the CTCP mechanism: the Mn values of the obtained polymers increased in proportion to monomer conversion and to the feed ratio of monomer to initiator. Moreover, successive CTCP using the fluorene-thiophene monomer, dioctylfluorene monomer, and 3-hexylthiophene monomer with AmPhos Pd initiator yielded a variety of all-conjugated di- and triblock copolymers.

We report a 3-component reaction between N-benzyl ketimines, [1.1.1]propellane, and pinacol boronates to generate benzylamine bicyclo[1.1.1]pentane (BCP) pinacol boronates. These structures are analogous to highly sought diarylmethanamine cores, which are common motifs in bioactive molecules. We demonstrate the versatility of the boronate ester handle via downstream functionalization through a variety of reactions, including a challenging Pd-catalyzed (hetero)arylation that exhibits a broad substrate scope. Together, these methods enable the synthesis of high-value BCP benzylamines which are inaccessible by existing methods. Furthermore, we demonstrate the successful application of these newly developed (hetero)arylation conditions to a variety of challenging tertiary pinacol boronates, including nitrogen-containing heterocycles, 1,1-disubstituted cyclopropanes, and other BCP cores., We report a 3-component reaction between N-benzyl ketimines, [1.1.1]propellane, and pinacol boronates to generate benzylamine bicyclo[1.1.1]pentane (BCP) pinacol boronates.

The reaction of bicyclo[1.1.0]butyl pinacol boronic ester (BCB‐Bpin) with nucleophiles has been studied. Unlike BCBs bearing electron‐withdrawing groups, which react with nucleophiles at the β‐position, BCB‐Bpin reacts with a diverse set of heteroatom (O, S, N)‐centred nucleophiles exclusively at the α‐position. Aliphatic alcohols, phenols, carboxylic acids, thiols and sulfonamides were found to be competent nucleophiles, providing ready access to α‐heteroatom‐substituted cyclobutyl boronic esters. In contrast, sterically hindered bis‐sulfonamides and related nucleophiles reacted with BCB‐Bpin at the β’‐position leading to cyclopropanes with high trans‐selectivity. The origin of selectivity is discussed.

The synthetically versatile pinacol boronic ester group (Bpin) is generally thought of as a bulky moiety because of the two adjacent quaternary sp3 -hydribized carbon atoms in its diol backbone. However, recent diastereoselective reactions reported in the literature have cast doubt on this perception. Reported herein is a detailed experimental and computational analysis of Bpin and structurally related boronic esters which allows determination of three different steric parameters for the Bpin group: the A-value, ligand cone angle, and percent buried volume. All three parameters suggest that the Bpin moiety is remarkably small, with the planarity of the oxygen-boron-oxygen motif playing an important role in minimising steric interactions. Of the three steric parameters, percent buried volume provides the best correlation between steric size and diastereoselectivity in a Diels-Alder reaction.

We report a reactive oxygen species (ROS)-stimulus-responsive phenylboronic acid pinacol ester nanocarrier, loaded with guanidine-modified 10-hydroxycamptothecin (HCPT) prodrug, to create a drug de...

Asymmetric total syntheses of naphthylisoquinoline alkaloids with a (P)-configuration are described. An atroposelective Suzuki–Miyaura reaction between naphthyl pinacol boronate and an aryl iodide ...

An efficient copper-catalyzed regioselective C-H alkenylation and borylative alkylation of quinoline N-oxides with vinyl arenes in the presence of pinacol diborane has been developed. The reaction proceeds through the borylcupration of the vinyl arenes followed by nucleophilic attack of the resulting alkyl copper species to the quinoline N-oxides. Benzoquinone and KOt Bu were identified as the necessary additives at the second step of the reaction that are crucial for the success of the reaction. A wide range of C2-functionalizaed quinolines were obtained with good functional group tolerance, which may find utilities in pharmaceuticals and synthetic chemistry.

Visible light-driven C–C bond formation has attracted increasing attention recently, thanks to the advance in molecular photosensitizers and organometallic catalysts. Nevertheless, these homogeneou...

New synthetic routes to (±)-clivonine were devised starting with the Diels-Alder cycloadditions of 3,5-dibromo-2-pyrone with styrene pinacol boronate dienophiles. In the first-generation synthesis, the pivotal perhydroindoline system including the C5-hydroxyl group was constructed via a reaction sequence involving the Eschenmoser-Claisen rearrangement and regio/stereoselective epoxide opening reaction. In the second-generation synthesis, a radical-mediated cyclization approach was employed for the rapid assembly of the pyrrolidine ring. In this route, the C5-hydroxyl group provided by the dienophile in a stereochemically defined form was preserved throughout the synthesis.

The utilization of diphenyl sulfoxides as versatile electrophilic coupling partners for the Suzuki–Miyaura reaction via C–S bond cleavage was successfully developed under palladium-N-heterocyclic carbene catalysis. The reactions showed good functional group compatibility, proceeded well under mild conditions, and provided biaryls in yields of up to 96%. A wide range of useful functional groups, such as fluoro, chloro, ether, hydroxyl, amide, cyano, keto, trimethylsilyl (TMS), and ester were tolerated under the reaction conditions; however, the use of phenylboronic anhydride and arylboronic acid pinacol esters generally would lead low yields. Good regioselectivity for the electron-poor phenyl group was achieved when unsymmetrical diphenyl sulfoxides were used. The protocol is applicable at the gram scale even with half the amount of catalyst. Density functional theory calculations were performed to investigate the reaction mechanism, indicating that the reaction occurred through oxidative addition, transmetalation, and reductive elimination to provide the final coupling product.

We found that the α-boryl radical of potassium alkyltrifluoroborate shows higher reactivity compared to the α-boryl radicals of alkylboronic acid pinacol ester and alkyl N-methyl imidodiacetic acid (MIDA) boronate in the halogen atom abstraction step of atom-transfer radical addition (ATRA) between alkyl bromide and vinylborons. In this research, an ATRA of alkyl halides with potassium vinyltrifluoroborate furnished unique alkylborons, which are difficult to synthesize by other methods.

A one-pot two-step protocol for the direct synthesis of boron-handled glycol derivatives is reported. The procedure starts by an NHC–boryl-radical-promoted regioselective hydroboration of glycol-protected cinnamaldehydes. After that, the reaction mixture is treated with pinacol in the presence of HCl, leading to the direct formation of pinacol boronate handled glycol monoalkyl ethers. In this acid-triggered conversion, a reductive ring-opening of glycol-derived acetal moiety takes place, during which an NHC–borane unit serves as the hydride source.

The generation of carbon-centered radicals from air-sensitive organoboron compounds through nucleohomolytic substitution at boron is a general method to generate non-functionalized and functionalized radicals. Due to their reduced Lewis acidity, alkylboronic pinacol esters are not suitable substrates. We report their in situ conversion into alkylboronic catechol esters by boron-transesterification with a substoichiometric amount of catechol methyl borate combined with an array of radical chain processes. This simple one-pot radical-chain deboronative method enables the conversion of pinacol boronic esters into iodides, bromides, chlorides, and thioethers. The process is also suitable the formation of nitriles and allylated compounds through C−C bond formation using sulfonyl radical traps. The power of combining radical and classical boron chemistry is illustrated with a modular 5-membered ring formation using a combination of three-component coupling and protodeboronative cyclization.

Propargyl alcohols, on treatment with MHMDS (M=Na, K), B2(pin)2, an acid chloride and a palladium/copper co‐catalyst system, undergo a reaction cascade comprised of trans‐diboration, regioselective acylation, cyclization and dehydration to give trisubstituted furylboronic acid pinacol ester derivatives in good yields; subsequent Suzuki coupling allows a fourth substituent of choice to be introduced and hence tetrasubstituted (arylated) furans to be formed. In terms of modularity, the method seems unrivaled, not least because each product can be attained by two orthogonal but convergent ways (“diagonal split”). This asset is illustrated by the “serial” formation of a “library” of all twelve possible furan isomers that result from systematic permutation of four different substituents about the heterocyclic core., As you like it: Propargyl alcohols can be transformed in a single step into 3‐borylated‐2,4,5‐triarylated furans by an efficient trans‐carboboration/cyclization/dehydration cascade. A subsequent Suzuki coupling allows a fourth substituent of choice to be introduced. The modularity of the method is unrivaled in that it allows four different substituents to be introduced in a programmable manner and hence all isomers of the multiply arylated furan to be attained.

The solubilities of phenylboronic acid, its pinacol ester and azaester in organic solvents (chloroform, 3-pentanone, acetone, dipropyl ether and methylcyclohexane) have been determined experimentally by a dynamic method, in which the disappearance of turbidity was determined by measuring of light intensity using a luminance probe. Phenylboronic acid has high solubility in ether and ketones, moderate in chloroform and very low in hydrocarbon. Pinacol ester and azaester show better solubility than the parent acid in all tested solvents. For pinacol ester differences between particular solvents are small, while for azaester the differences are significant. For both esters the highest solubility is observed in chloroform and the lowest in the hydrocarbon. The results have been correlated by the Wilson, NRTL and Redlich–Kister equations. For the phenylboronic acid better correlation of the data is obtained by polynomials in comparison with the above equations. It is connected with additional acid-anhydride equilibrium in the system. The influence of polarity of the solvents on the solubility is discussed.

A cobalt-catalyzed asymmetric cross-coupling of α-bromo-α-fluorotoluene derivatives with a variety of aryl zincates derived from lithium aryl n-butyl pinacol boronates and ZnBr2 under mild reaction...

The synthesis of ten ortho-fused PAHs bearing boronic pinacol ester groups (BPin) is reported. The products are obtained via modification of Mallory photocyclization in 45–99% yields. Among them are examples of highly strained molecules such as [4]helicene derivatives with BPin substituents in the cavity. The method allows double C–C coupling and tolerates more than one BPin functionality.

[18F]6-fluoro-L-DOPA ([18F]FDOPA) is a diagnostic radiopharmaceutical for positron emission tomography (PET) imaging that is used to image Parkinson's disease, brain tumors, and focal hyperinsulinism of infancy. Despite these important applications, [18F]FDOPA PET remains underutilized because of synthetic challenges associated with accessing the radiotracer for clinical use; these stem from the need to radiofluorinate a highly electron-rich catechol ring in the presence of an amino acid. To address this longstanding challenge in the PET radiochemistry community, we have developed a one-pot, two-step synthesis of high-molar-activity [18F]FDOPA by Cu-mediated fluorination of a pinacol boronate (BPin) precursor. The method is fully automated, has been validated to work well at two separate sites (an academic facility with a cyclotron on site and an industry lab purchasing [18F]fluoride from an outside vendor), and provides [18F]FDOPA in reasonable radiochemical yield (2.44 ± 0.70 GBq, 66 ± 19 mCi, 5 ± 1%), excellent radiochemical purity (>98%) and high molar activity (76 ± 30 TBq/mmol, 2,050 ± 804 Ci/mmol), n = 26. Herein we report a detailed protocol for the synthesis of [18F]FDOPA that has been successfully implemented at two sites and validated for production of the radiotracer for human use.

The pH and reactive oxygen species (ROS) dual-responsive supramolecular vesicle utilizing a novel host-guest molecular recognition between a phenylboronic acid pinacol ester derivative carrying long alkyl chain (PBEC12A) and carboxylated pillar[6]arene (CP[6]) is developed. The host-guest complexation between CP[6] and PBEC12A was first studied in aqueous solution. PBEC12A was encapsulated within CP[6] forming a stable host-guest complex with a binding constant as high as 106 M-1 order of magnitude. The driving force behind such a host-guest recognition was the combination of electrostatic interaction and hydrophobic effect. Then, the self-assembly of the supra-amphiphiles of PBEC12A-CP[6] host-guest complexes was investigated in aqueous solution through high-resolution transmission electron microscope and dynamic light scattering. It was found that the supra-amphiphiles self-assembled into supramolecular vesicles and the size of the self-assembled supramolecular vesicles could be tuned from 25 to 200 nm by varying the ratio of CP[6] to PBEC12A. To demonstrate the pH- and ROS-responsive properties of the self-assembled vesicles, the supramolecular vesicles self-assembled from PBEC12A/CP[6] (5:1) were utilized. The Nile Red loading and release studies demonstrated that the supramolecular vesicles possessed good pH/ROS dual-responsive properties. This study enriches the field of supra-amphiphile based on noncovalent interactions. It is anticipated that the pH/ROS dual-responsive supramolecular vesicles have potential applications in drug-delivery systems because both the stimuli are in close relation with specific microenvironments of tumors and relevant diseases of the human body.

The acidity of the chiral Bronsted acid catalysts is crucial for the catalytic efficiency, the highly acidic BINOL-derived chiral N-triflylphosphoramides can provide effective asymmetric catalysis for rearrangement reactions. Despite multiple interactions between the basic/acidic sites of the functional group and the substrates have been evaluated, the origin of high catalytic activity and excellent enantioselelctivity of N-triflylphosphoramides catalyst is still challenging. Especially the role of CF3 groups in controlling activation mode and determining enantioselectivity. Thus, two effective case reactions of pinacol and acyloin rearrangement catalyzed by BINOL N-triflyphosphoramide were employed to provide basis understanding for these issues. Our calculations reveal that the P(=NTf)OH tautomer of N-triflyphosphoramide is an active catalyst form for the rearrangement reaction, differing from previous proposed model involving P(=O)NHTf group. This can be ascribed to the additional C–F···π interaction between the CF3 group of catalyst and the migration group of substrate in the preferred activation model. Furthermore, we found that the CF3 substituent on the central functional group effectively aids the bifunctional activation and improves catalytic activity of N-triflyphosphoramide catalyst. More importantly, the CF3 substituent and the orientation of migration groups play a significant role in controlling the enantioselectivity by contributing different strength multiple C–H···F, C–F···π, and C–H···π interactions between catalyst and substrate. Overall, our findings on the factors affecting the stereochemical control may show utility for other challenging asymmetric reactions catalyzed by chiral N-triflylphosphoramides.

Radical formation is the initial step for conventional radical chemistry. Reported herein is a unified strategy to generate radicals in situ from aromatic β-ketoesters by using a photocatalyst. Under visible-light irradiation, a small amount of photocatalyst fac-Ir(ppy)3 generates a transient α-carbonyl radical and persistent ketyl radical in situ. In contrast to the well-established approaches, neither stoichiometric external oxidant nor reductant is required for this reaction. The synthetic utility is demonstrated by pinacol coupling of ketyl radicals and benzannulation of α-carbonyl radicals with alkynes to give a series of highly substituted 1-naphthols in good to excellent yields. The readily available photocatalyst, mild reaction conditions, broad substrate scope, and high functional-group tolerance make this reaction a useful synthetic tool.

The propargylation of aldehydes promoted by microwave irradiation using allenylboron compounds in a chemo- and regioselective way is described. The corresponding products were obtained in short reaction time, high yield and purity without the need of any solvent when allenylboronic acid pinacol ester was used, or using a minimal amount of acetone when potassium allenyltrifluoroborate was used.

A process for the concurrent transfer of both the NHC ligand and the difluoromethyl group from [(SIPr)Ag(CF2H)] to PdX2 (X = Cl, OAc, and OPiv) for the preparation of [(SIPr)Pd(CF2H)X] complexes is described. These complexes were air-stable and easily underwent transmetalation with aryl pinacol boronate/reductive elimination to generate ArCF2H in high yields. Based on this discovery, the first one-pot C-H borylation and difluoromethylation process for the preparation of difluoromethylated (hetero)arenes was developed.

The aminoazanium of DABCO (H2 N-DABCO) has been developed as a general and practical amination reagent for the direct amination of alkyl and aryl pinacol boronates. This compound is stable and practical for use as a reagent. Various primary, secondary. and tertiary alkyl-Bpin and aryl-Bpin substrates were aminated to give the corresponding amine derivatives. The amination is stereospecific. The anti-Markovnikov hydroamination of olefins was easily achieved by catalytic hydroboration with HBpin and in subsequent situ amination using H2 N-DABCO. Moreover, the combination of 1,2-diboration of olefins, using B2 pin2 , with this amination process achieved the unprecedented 1,2-diamination of olefins. The amination protocol was also successfully extended to aryl pinacol boronates.