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The thioether-directed regioselective cycloaddition of internal alkynes with azides was enabled by the in situ generated cationic Ir species, providing modular access to complex S-containing triazoles.

A rapid construction of 9-arylfluorenes and spirobifluorenes was developed through the tandem Pd-catalysed C–H arylation/demaminative annulation of 1,1-diarylmethylamines with aromatic iodides.

The aromatic C–H bond etherification with alcohols is one of the most atom-efficient ways to construct aryl ethers. However, it often requires a large excess of alcohols as etherification reagents,...

The Pd-cataylsed direct ortho-C(sp2)–H fluorination of aromatic ketones has been developed for the first time. The reaction features good regioselectivity and simple operations, constituting an alternative shortcut to access fluorinated ketones. A concise synthesis of anacetrapib has also been achieved by using late-stage C–H fluorination as a key step.

A new and efficient strategy for ring-opening reactions of nitrocyclopropanes is developed for the first time for the divergent synthesis of enynes and enesters via in situ generated highly reactive electron-deficient intermediate allenes. Controllable approaches resulted in enynes and enesters with up to 89% and 90% yields, respectively. The reaction features easy operation, involves green solvents and simple inorganic bases, and is transition-metal free.

An efficient ruthenium-catalyzed method has been developed for the direct N-alkylation of sulfur-containing amines with alcohols, for the first time, by a step-economical and environmentally friendly hydrogen borrowing strategy. The present methodology features base-free conditions and broad substrate scope, with water being the only by-product. Moreover, this protocol has been applied to the synthesis of the pharmaceutical drug Quetiapine.

An efficient Pd-catalysed β-C(sp3)–H arylation of diverse native amides with aryl iodides was developed. This protocol overcomes the necessity of the Thorpe–Ingold effect and features broad substrate scope and good functional group tolerance. The potential application of this protocol is collectively demonstrated by gram-scale synthesis and the synthesis of several bioactive molecules.

Herein, we report a novel strategy to access CH2F-containing ketones through Pd-catalysed β-selective methyl C(sp3)-H fluorination. The reaction features high regioselectivity and a broad substrate scope, constituting a modular method for the late-stage transformation of the native methyl (CH3) into the monofluoromethyl (CH2F) group.

We describe here a Ni-catalysed deamidative fluorination of diverse amides with electrophilic fluorinating reagents. Different types of amides including aromatic amides and olefinic amides were well compatible, affording the corresponding acyl fluorides in good to excellent yields.

The functionalization of indoles in the carbocyclic ring has been achieved via organocatalytic enantioselective Friedel–Crafts benzhydrylation of hydroxyindoles with in situ generated ortho-quinome...

Selective C(sp3)–C(sp2) bond construction is of central interest in chemical synthesis. Despite the success of classic cross-coupling reactions, the cross-dehydrogenative coupling between inert C(s...

A nitrate-promoted Pd-catalysed mild cross-dehydrogenative C(sp2)-H bond oxidation of oximes or azobenzenes with diverse carboxylic acids has been developed. In contrast to the previous catalytic systems, this protocol features mild conditions (close to room temperature for most cases) and a broad substrate scope (up to 64 examples), thus constituting a versatile method to directly prepare diverse O-aryl esters. Moreover, the superiority of the nitrate additive in this mild transformation was further determined by experimental and computational evidence.

An efficient Pd-catalysed β-C(sp

A highly straightforward route to enantiomerically enriched spiro-benzofuran pyrazolones has been achieved via chiral amine squaramide catalyzed [4 + 1] annulation of in situ generated ortho-quinomethanes with the novel C1 synthons of 4-halo pyrazolones. In oil–water biphases, high yields (up to 95%) and high to excellent stereoselectivities (up to 99 : 1 dr, 99% ee) of the resulting 4-spiropyrazolones with a wide substrate scope could be achieved. Furthermore, the present protocol provided an arbitrary access to all four possible stereoisomers of the spiro-benzofuran pyrazolones via an appropriate choice of C1 synthons and chiral catalysts.

A chiral amine squaramide catalyzed the conjugated addition of pyrazolin-5-ones to in situ generated ortho-quinomethanes (o-QMs) was developed to construct 4-tetrasubstituted pyrazolin-5-ones featuring adjacent quaternary and tertiary stereocenters in oil–water phases. High yields, excellent stereoselectivities, mild conditions and accessible scale-up demonstrated the fascination of this reaction protocol.

A detailed mechanism study on the anion ligand promoted selective C–H bond fluorination is reported. The role of the anion ligand has been clarified by experimental evidence and DFT calculations. Moreover, the nitrate promoted C–F bond reductive elimination enabled a selective C–H bond fluorination of various symmetric and asymmetric azobenzenes to access diverse o-fluoroanilines.

An efficient ruthenium-catalyzed method has been developed for the direct N-alkylation of sulfur-containing amines with alcohols, for the first time, by a step-economical and environmentally friendly hydrogen borrowing strategy. The present methodology features base-free conditions and broad substrate scope, with water being the only by-product. Moreover, this protocol has been applied to the synthesis of the pharmaceutical drug Quetiapine.

The Pd-cataylsed direct ortho-C(sp2)-H fluorination of aromatic ketones has been developed for the first time. The reaction features good regioselectivity and simple operations, constituting an alternative shortcut to access fluorinated ketones. A concise synthesis of anacetrapib has also been achieved by using late-stage C-H fluorination as a key step.

Herein, we report a novel strategy to access CH2F-containing ketones through Pd-catalysed β-selective methyl C(sp3)-H fluorination. The reaction features high regioselectivity and a broad substrate scope, constituting a modular method for the late-stage transformation of the native methyl (CH3) into the monofluoromethyl (CH2F) group.

Herein we report a novel Cu-catalyzed regioselective C2-H alkylation of benzimidazoles with aromatic alkenes. The reaction features exclusive regioselectivity and broad substrate scope in the intermolecular alkylation of benzimidazoles with terminal and internal aromatic alkenes, constituting a modular access toward benzimidazole-containing 1,1-di(hetero)aryl alkanes. The intramolecular C2-H alkylation of benzimidazoles with aromatic alkenes has been achieved in an endo-selective manner. The enantioselective C2 alkylation of benzimidazoles has also been realized with moderate to good stereocontrol.

A nitrate-promoted Pd-catalysed mild cross-dehydrogenative C(sp

The association between lung and intestine has already been reported, but the differences in community structures or functions between lung and intestine bacteria yet need to explore. To explore the differences in community structures or functions, the lung tissues and fecal contents in rats were collected and analyzed through 16S rRNA sequencing. It was found that intestine bacteria was more abundant and diverse than lung bacteria. In intestine bacteria, Firmicutes and Bacteroides were identified as major phyla while Lactobacillus was among the most abundant genus. However, in lung the major identified phylum was Proteobacteria and genus Pseudomonas was most prominent genus. On the other hand, in contrast the lung bacteria was more concentrated in cytoskeleton and function in energy production and conversion. While, intestine bacteria were enriched in RNA processing, modification chromatin structure, dynamics and amino acid metabolism. The study provides the basis for understanding the relationships between lung and intestine bacteria.

Selective C(sp

A versatile and site-selective nitrate-promoted C-H bond fluorination using various weak coordinating amides as intrinsic directing groups was developed. Diverse tertiary and secondary amides underwent selective aromatic C-H bond fluorination, which features broad substrate scope, good regioselectivity, and mild conditions. Moreover, the late-stage C-H bond fluorination of the challenging benzeneacetamides via distal directing was reported for the first time.

A catalytic asymmetric method for the synthesis of polysubstituted chromans via an oxa-Michael-nitro-Michael reaction has been developed. The squaramide-catalyzed domino reaction of 2-hydroxynitrostyrenes with trans-β-nitroolefins produced chiral chromans with excellent enantioselectivities (up to 99% ee), diastereoselectivities (up to >20 : 1 dr), and moderate to good yields (up to 82%).

An unprecedented and challenging simultaneous carboxylation/halogenation, and next lactonization of γ,γ-dicarbonyl-substituted aldehydes has been realized using an eco-friendly, safe and inexpensive solid sodium chlorite (NaClO2)/1,3-dibromo-5,5-dimethyl-hydantoin (DBDMH) combination. This new reaction is amenable to a multi-gram scale-up with high yield.

A detailed mechanism study on the anion ligand promoted selective C-H bond fluorination is reported. The role of the anion ligand has been clarified by experimental evidence and DFT calculations. Moreover, the nitrate promoted C-F bond reductive elimination enabled a selective C-H bond fluorination of various symmetric and asymmetric azobenzenes to access diverse o-fluoroanilines.

A fast and site-selective biaryl synthesis via dehydrogenative C–H/C–H arylation in a ball mill was developed. In this paper, both electron-deficient oximes and electron-rich anilides quickly and under mild conditions provided arylation with various arenes to give the biaryl products in high-level selectivity. Given the solventless mechanochemical conditions, the transformation obviated the use of large amounts of arene coupling partners as solvents and allowed utilization of more-complicated and more-expensive arenes as coupling partners, which may dramatically enhance the application prospect of the C–H/C–H arylation strategy.

A new and efficient catalytic strategy that combines asymmetric organocatalysis and iodine catalysis was first developed for the one-pot Michael/iodization/SN2 nucleophilic substitution sequential catalytic synthesis of spirodihydrobenzofuran pyrazolones and spirodihydrobenzofuran oxindoles. The approach results in products with moderate to high yields (up to 93%), high to excellent enantioselectivities (up to 99% ee), and excellent diastereoselectivities (up to >99:1 dr). The reaction features simple operation and is metal-free and base-free.

The successful development of the classical Pinnick oxidation into a new and promising oxidative lactonization reaction is reported. Chiral 3-oxindolepropionic aldehydes, Michael adducts of 3-olefinic oxindoles with aliphatic aldehydes, are directly converted to spirocyclic oxindole-γ-lactones solely by sodium chlorite via a tandem Pinnick oxidation/chlorination/substitution sequence. This reaction uses waste ClO– generated in the initial Pinnick oxidation as an ecofriendly halogenating agent for the subsequent chlorination, and then it utilizes the byproduct OH– formed in the chlorination to facilitate the final internal substitution.

A catalytic asymmetric method for the synthesis of polysubstituted chromans

A facile and site-selective C–H bond fluorination of phenols using removable 2-pyridyloxy group as an auxiliary was developed. Alternatively, late-stage C–H bond fluorination of bioactive 2-phenoxyl nicotinate derivatives and diflufenican were also feasible under the present strategy.

The title compound, (E)-methyl 2-(methoxyimino)-2-(2-((3-(6-(trifluoromethyl)pyridin-3-yl) phenoxy) methyl) phenyl) acetate was synthesized and characterized by 1H and 13C NMR, IR, and MS spectroscopy. Its molecular structure was investigated by X-ray crystallography. The crystal structure analysis revealed that the two independent molecules interact via C‒H···O to form a dimer, which is further connected by weak interaction with another dimer to constitute a four molecular crystal packing. At the same time, two molecules are linked by weak intermolecular C13-O3 and O3-H15 interactions to constitute a ring involving six atoms (C13/C12/C14/C15/H15/O3), which are not in the same plane. Compound (5) crystallizes in a monoclinic system, space group P121/c1, a = 7.2024(4) A, b = 8.4592(6) A, c = 35.389(2) A.

Genetic diversity and relationship of Lycoris species were investigated using SCoT marker analysis. Of 57 SCoT primers screened, 23 SCoT primers were identified to be high polymorphism. A total of 154 DNA bands with size varied from 0.2 kb to 2.5 kb were amplified, and 131 (82.5%) of them were polymorphic. The average number of polymorphic DNA band per primer was 5.7. Based on Nei's similarity coefficients and genetic distances, total of 43 accessions from 14 species of the genus Lycoris tested were clustered into four groups. Group I consisting of 17 accessions was further divided into two subgroup (Ia and Ib). Subgroup Ia included four species with red flower and 22 (2n) chromosomes. Subgroup Ib contained Lycoris haywardii and Lycoris albiflora which were natural hybrids with oyster white flower. Group II consisted of three species with yellow flower and 16 (2n) chromosomes. Group III was composed of Lycoris Squamigera, Lycoris incarnata and all of hybrids whose flower color was variegated. Group IV only has one species (Lycoris sprengeri) whose petal was a mixture of pink and blue. Notably, the polymorphism generated by SCoT was associated with flower color and chromosome number in this genus plants. The present data provide high-valued information for the management of germplasm, genetic improvement, and conservation of the genetic resources of Lycoris species, important horticulture and medical plants.

An organocatalytic domino thia-Michael/ aldol condensation reaction of α, β-unsaturated aldehydes with 1, 4-dithiane-2,5-diol catalyzed by chiral diphenylprolinol TMS ether has been developed, which provides a new practical and direct route to chiral dihydrothiophenes with high yields (up to 90%) and excellent enantioselectivities (up to>99% ee). The catalytic mechanism of the domino reaction was further confirmed through the APCI-MS detection of proposed reaction intermediates.

Both 1,5-benzodiazepine and quinoxaline derivatives are important heterocycles in pharmaceuticals. We describe an efficient and clean method for the synthesis of 1,5-benzodiazepines from o-phenylenediamine and ketones catalyzed by sodium tetrachloroaurate(III) dihydrate under mild conditions. The catalyst was shown to be equally effective for the synthesis of quinoxalines from o-phenylenediamine and alpha-bromo ketones under the similar reaction conditions. This method produced good yields.

A new compound having potential bioactivities 3,5-dichloro-6-morpholinopyridin-2-ol (1) was synthesized and characterized by single crystal X-diffraction. The crystal is monoclinic, space group P21/c with a = 10.3609 (6), b = 10.5711 (7), c = 10.3190 (5) A, β = 108.9433 (15)°, V = 1068.99 (11) A3, Z = 4, C9H10Cl2N2O2, D c = 1.548 g/cm3, μ (MoKα) = 0.71075 A, S = 1.01, F (000) = 512.00, R = 0.0397 and wR = 0.1364. In the unit cell, there are two independent molecules linked by intermolecular O–H···O (2.693(2) A) hydrogen bonds forming onedimensional expanded structure. As part of our ongoing research work on pyridine derivatives, the title compound crystal structure is important to study the relationship between the structure and its biological activities, thus it is urgent to publish in time.

Pendimethalin (6) is a well-known selective herbicide useful for pre-emergence control of annual broad-leaved weeds and grasses in cotton, soybeans, rice, barley, beans, alliums, vines, ornamentals...

In this paper, we presented a novel method for the facile and efficient one-pot synthesis of 2-arylbenzoxazoles, which were directly synthesized from 2-aminophenol and aldehydes catalyzed by hydrogen tetrachloroaurate (HAuCl(4).4H(2)O) under an oxygen atmosphere with anhydrous tetrahydrofuran (THF) as solvent or in solvent-free condition. The results show that this method could bring excellent yields as high as 96%. THF was proven to be the best choice among several solvents screened and the reaction was tolerated with a variety of aromatic aldehydes possessing electron-donating or withdrawing groups. The advantages of the present method lie in catalytic process using economic and environmentally benign dioxygen as oxidant.

A three‐component asymmetric Mannich reaction of isovaleraldehyde, methyl ketones, and aromatic amines was efficiently synergistic catalyzed by amide‐task‐specific ionic liquids (AILs)/L‐proline under mild conditions. The corresponding asymmetric Mannich reaction adducts were obtained in moderate to high yields and stereo selectivity in all the cases tested. The product was easily isolated, and the remaining catalysis system can be readily recovered and reused at least three times without significant loss of catalytic activity and selectivity.

Sm/TiCl4 system could well integrate the high reactivity of samarium(II) and high deoxygenation capacity of low valent titanium within one system. In this paper, the intermolecular and intramolecular reductive coupling reactions of ketones with esters mediated by metallic samarium (Sm) and a catalytic amount of titanium tetrachloride (TiCl4) were successfully developed. A series of substituted ketones and cyclic β-keto-esters were prepared in moderate to good yields under reflux and neutral conditions.

Amide ionic liquids (AILs)/ L -proline synergistic catalyzed Mannich reactions of isovaleraldehyde, methyl ketones, and aromatic amines were earned out in moderate to high yields (up to 96%) and high stereo selectivities (>99% e.e.). The products were easily isolated by extraction; and the catalyst system was readily recycled at least thrice without significant loss of efficiency. The scope of the substrates was studied and the interpretation of the manifest improvement of the reaction rates and enantio-selectivity of the novel catalyst system was speculated.

For realizing the real-time monitoring of organic thin film preparation process in vacuum environment, the present paper proposes a high precision measurement approach based on differential reflectance spectroscopy (DRS). An optical system was constructed with off the shelf optical components, such as off-axis parabolic mirror, optical flat and optical fiber. A differential algorithm was employed to analyze the spectral signals. Based on the homebuilt setup, instability induced by variation of temperature was investigated. It was concluded that with the good control of temperature and air flow, the measurement repeatability of this system is better than 2 per thousand for a long-term period. Furthermore, an initial stage of organic thin film growth of pentacene molecules on the surface of Au was studied. As compared with the data of film thickness gauge and atomic force microscope, DR spectra accurately recorded the fine optical evolution with sub-monolayer resolution, which is related to the growth of the thin film. As a result, the DR optical system exhibits characteristics of broad spectrum (range from 300 to 820 nm), high stability (repeatability better than 2X 10(-3)), and high precision (sub-monolayer resolution) after efforts were done to decrease the influences on the spectral quality produced by misalignments of the optical components, the defects of the optics, and the disturbances of the environmental conditions. It is indicated that the proposed DR method is suitable for real-time online monitoring of thin film growth with high precision.

A simple and convenient procedure for stereoselective synthesis of (Z)-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCl system to form selenide anions, which then undergo S(N)2' substitution of Baylis-Hillman adducts to produce the (Z)-allyl selenides.

(2005). A NOVEL SYNTHESIS OF 2-CHLORO-4-FLUORO-5-NITROBENZENESULFONYL CHLORIDE. Organic Preparations and Procedures International: Vol. 37, No. 6, pp. 566-569.