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An efficient catalytic asymmetric electrophilic sulfenylation reaction for the synthesis of planar-chiral sulfur-containing cyclophanes has been developed for the first time. This was achieved by using a new Lewis base catalyst and a new ortho-trifluoromethyl-substituted sulfenylating reagent. Using the substrates with low rotational energy barrier, the transformation proceeded through a dynamic kinetic resolution, and the high rotational energy barrier of the substrates allowed the reaction to undergo a kinetic resolution process. Meanwhile, this transformation was compatible with a desymmetrization process when the symmetric substrates were used. Various planar-chiral sulfur-containing cyclophanes were readily obtained in moderate to excellent yields with moderate to excellent enantioselectivities (up to 97 % yield and 95 % ee). This approach was used to synthesize pharmaceutically relevant planar-chiral sulfur-containing molecules. Density functional theory calculations showed that π-π interactions between the sulfenyl group and the aromatic ring in the substrate play a crucial role in enantioinduction in this sulfenylation reaction., (© 2024 Wiley-VCH GmbH.)

A tandem dearomative electrophilic thiocyanation/cyclization/acylation of indoles was developed for the first time, which is enabled by acyl chloride. A variety of 3-SCN pyrroloindolines were obtained with moderate to excellent yields. Interestingly, following replacement of acyl chloride with methanesulfonic acid, 2-SCN tryptamines were obtained using the same starting substrates and reagents. Furthermore, catalytic enantioselective manner of thiocyanation/cyclization/acylation reaction was also studied. An enantiomer self-disproportionation effect of 3-SCN pyrroloindolines was discovered. A series of chiral 3-SCN pyrroloindolines were obtained with high enantioselectivities., (© 2022 Wiley-VCH GmbH.)

Given alkynyl group is an important functional unit, a variety of efficient methods have been developed to construct alkynyl-containing compounds. Among them, the alkynylative difunctionalization of alkenes is one of the most straightforward and efficient strategies for preparing these compounds and so has made great progress in recent years, including the catalytic asymmetric manner. However, there is no comprehensive review to summarize these studies. This review is aimed at comprehensively summarizing the alkynylative difunctionalization of alkenes, which is presented in terms of alkynylation-initiated and alkynylation-terminated difunctionalizations of alkenes. We hope that this review will help to encourage more researchers to further explore in this field., (© 2022 Wiley-VCH GmbH.)

Atroposelective electrophilic sulfenylation of N-aryl aminoquinone derivatives has been achieved for the first time. This transformation is enabled by a new chiral 6,6'-disubstituted SPINOL-derived sulfide catalyst, which was first synthesized and then successfully explored for catalyzing enantioselective reactions. Various axially chiral sulfur-containing diarylamine derivatives were readily obtained in moderate to excellent yields with moderate to excellent enantioselectivities. A class of relatively flexible stereogenic C-N axes was easily constructed. The experimental results and a computational study suggested that an intramolecular N-H⋅⋅⋅S hydrogen bond is important for the stability of the C-N axis, which is consistent with our hypothesis. Density functional theory calculations revealed the origin of atroposelectivity and underscored the importance of catalyst rigidity in this sulfenylation reaction., (© 2022 Wiley-VCH GmbH.)

A phosphoric acid catalyzed electrophilic thiocyanation of 3-aryl indoles, which provides an efficient and modular approach to SCN-containing 3-aryl indole compounds, was developed for the first time. A variety of 2-SCN-3-aryl indoles were obtained with moderate to excellent yields. Furthermore, catalytic asymmetric manner of this reaction was also studied. Using chiral phosphoric acid as the catalyst, axially chiral SCN-containing 3-aryl indoles were obtained in moderate to good yields with moderate enantioselectivity., (© 2022 Wiley-VCH GmbH.)

A divergent strategy for the facile preparation of various enantioenriched phenylthio-substituted lactones was developed based on Lewis base/Brønsted acid co-catalyzed thiolation of homoallylic acids. The acid-controlled regiodivergent cyclization (6-endo vs. 5-exo) and acid-mediated stereoselective rearrangement of phenylthio-substituted lactones were explored. Experimental and computational studies were performed to clarify the origins of the regioselectivity and enantioselectivity. The calculation results suggest that C-O and C-S bond formation might occur simultaneously, without formation of a commonly supposed catalyst-coordinated thiiranium ion intermediate and the potential π-π stacking between substrate and SPh as an important factor in the enantio-determining step. Finally, this methodology was applied in the rapid syntheses of the bioactive natural products (+)-ricciocarpin A and (R)-dodecan-4-olide., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An enantioselective sulfenylation/semipinacol rearrangement of 1,1-disubstituted and trisubstituted allylic alcohols was accomplished with a chiral Lewis base and a chiral Brønsted acid as cocatalysts, generating various β-arylthio ketones bearing an all-carbon quaternary center in moderate to excellent yields and excellent enantioselectivities. These chiral arylthio ketone products are common intermediates with many applications, for example, in the design of new chiral catalysts/ligands and the total synthesis of natural products. Computational studies (DFT calculations) were carried out to explain the enantioselectivity and the role of the chiral Brønsted acid. Additionally, the synthetic utility of this method was exemplified by an enantioselective total synthesis of (-)-herbertene and a one-pot synthesis of a chiral sulfoxide and sulfone., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A series of Y-shaped sensitizers incorporating quinoxaline or quinoxalinoid moieties were prepared and applied in dye-sensitized solar cells (DSSCs). By the introduction of quinoxalinoid functionalities, the absorption extinction coefficients could be enhanced. The molecular structures were modified by introducing an extra acceptor group (A) between a donor (D) and a π-bridge (D-A-π-A) and also by incorporating electron-donating substituents at various positions of the quinoxalinoid moiety. Some of the dyes and mixtures thereof were found to exhibit good light-harvesting efficiencies under both sunlight and indoor light, with efficiencies up to 7.92 % under one sun (AM 1.5G). When operated under indoor light, the efficiency could be boosted to 27.76, 28.74, and 30.45 % under 600, 1000, 2500 lux illumination, respectively. The best performance could be ascribed partly to an improved dye coverage on the TiO 2 surface., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A novel chiral 1,5-N,N-bidentate ligand based on a spirocyclic pyrrolidine oxazoline backbone was designed and prepared, and it coordinates CuBr in situ to form an unprecedented catalyst that enables efficient oxidative cross-coupling of 2-naphthols. Air serves as an external oxidant and generates a series of C 1 -symmetric chiral BINOL derivatives with high enantioselectivity (up to 99 % ee) and good yield (up to 87 %). This approach is tolerant of a broader substrates scope, particularly substrates bearing various 3- and 3'-substituents. A preliminary investigation using one of the obtained C 1 -symmetric BINOL products was used as an organocatalyst, exhibiting better enantioselectivity than the previously reported organocatalyst, for the asymmetric α-alkylation of amino esters., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An efficient oximation method has been developed on the basis of NO + -initiated semipinacol rearrangement and subsequent proton elimination. The procedure enabled the rapid construction of a series of oximes and oxime ethers with spiro quaternary stereocenters from allylic silyl ethers. Additional features of this reaction include wide substrate tolerance as well as the commercial availability of the safe nitrosation reagent NOBF 4 . The key N-heterotricyclic cores of three natural alkaloids, tuberostemoninol B, (+)-quebrachidine, and an insecticide, were also constructed efficiently by this method., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An enantioselective redox-relay Heck alkynylation of di- and trisubstituted alkenols to construct propargylic stereocenters is disclosed using a new pyridine oxazoline ligand. This strategy allows direct access to chiral β-alkynyl carbonyl compounds employing allylic alcohol substrates in contrast to more traditional conjugate addition methods., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An asymmetric fluorination/semipinacol rearrangement of 2-oxa allylic alcohols, as catalyzed by cinchona-alkaloid derivatives, gives chiral β-fluoro ketones with moderate to high levels of enantioselectivity (see scheme). Both enantiomers of the product could be obtained by using the appropriate catalyst., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)