Article
Chemistry, Applied
Deyuan Meng, Jing He, Woojin Yoon, Hoseop Yun, Jung Tae Han, Jaesook Yun
Summary: In this study, the catalytic 1,6-addition of chiral alkyl copper nucleophiles generated from borylalkenes and a copper-hydride catalyst was successfully conducted under mild conditions. The controlled chemo- and stereoselectivity played a crucial role in the reductive coupling process, resulting in efficient synthesis of asymmetric 1,6-adducts of p-quinone methides through multicomponent and catalytic tandem reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Henning J. Loui, Arun Suneja, Christoph Schneider
Summary: A synthetic method has been developed for the stereoselective (3 + 3)-cycloannulation of in situ generated carbonyl ylides with indolyl-2-methides, resulting in oxa-bridged azepino[1,2-a]indoles in one step. The products, with three stereogenic centers, were obtained with good stereoselectivity and yields, showcasing valuable heterocyclic complexity.
Article
Chemistry, Physical
Guosong Shen, Faqian He, Wansen Xie, Huanchao Gu, Xiaoyu Yang
Summary: Asymmetric diastereodivergent catalysis is an important strategy for accessing different stereoisomers of a molecule. In this study, a new method for the asymmetric diastereodivergent synthesis of chromanes with C2,C3-contiguous tetrasubstituted stereocenters was reported using chiral phosphoric acid catalysts.
Article
Chemistry, Organic
Alemayehu Gashaw Woldegiorgis, Haorui Gu, Xufeng Lin
Summary: The organocatalytic asymmetric reactions of C2-unsubstituted racemic naphthyl-indoles with orthoalkynylnaphthols were used to synthesize axially chiral styrenes connected to an axially chiral naphthyl-indole unit. By employing chiral phosphoric acid as the catalyst, these axially chiral styrenes were obtained in good yields (up to 96%) and excellent stereoselectivity (up to >99.9% ee, >20:1 dr, and >99:1 E/Z) under mild conditions. Furthermore, further synthetic transformations were achieved with high yields and excellent stereocontrol.
Review
Chemistry, Physical
Mercedes Zurro, Aitor Maestro
Summary: This paper reviews the recent literature on the catalytic methodologies for the derivatization of aza-QM, including organocatalytic and organometallic approaches. The review analyzes various catalytic systems, involving chiral NHC carbenes, phosphoric acids, phosphoramidites, phosphine, copper, and palladium catalysis, showcasing their applicability for the synthesis of a diverse array of N-containing compounds, many of which exhibit biological activity.
Article
Chemistry, Organic
Jiaying Sun, Wenxuan Zhang, Ran Song, Daoshan Yang, Jian Lv
Summary: Catalytic direct [4 + 2] cycloaddition reactions and Friedel-Crafts reactions of ortho-alkynylnaphthols with benzofurans have been developed. They afford high yields of functionalized hydrobenzofuro[3,2-b]chromans and hydroarylation products, respectively, with high chemoselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Wu Yuzhu, Shen Panpan, Duan Wenzeng, Ma Yudao
Summary: The first carbene-catalyzed enantioselective 1,6-conjugate addition of boron to para-quinone methides was achieved using a commercially available chiral triazolium and bis(pinacolato)diboron. This reaction features mild conditions, broad substrate scope, excellent functional group tolerance, and good yield and enantioselectivity. Remarkably, even in the absence of any transition metals, the reaction proceeded well with just 0.1 mol% of catalyst loading without significant loss of yield and enantioselectivity, although longer reaction time was required.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jing Wang, Tingting Wang, Hongguang Du, Ning Chen, Jiaxi Xu, Zhanhui Yang
Summary: An iridium-catalyzed and phenol-directed deoxygenation method is described for the synthesis of 4-alkylphenols, which offers low catalyst loading, high functionality compatibility, and excellent site-selectivity. The applications in late-stage modification of steroids and gram-scale total synthesis of a Gastrodia elata extract are also highlighted. Mechanistically, the interemediacy of quinone methide controls the site-selectivity, and the formation of iridium hydride serves as the rate-limiting step.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Zhiguang Zhang, Xiaoyu Tan, Ao Sui, Bingzhu Zhang, Yong Zhang
Summary: A DBU-catalyzed 1,6-addition reaction of quinazolinones and quinolones with para-quinone methides under mild conditions is reported. Diarylmethane compounds functionalized with quinazolinones and quinolones were obtained in good yields (41-95%) with DBU as catalyst.
TETRAHEDRON LETTERS
(2022)
Article
Chemistry, Organic
Xiao Lin, Boming Shen, Ziyang Wang, Yuyu Cheng, Xuling Chen, Pengfei Li, Peiyuan Yu, Wenjun Li
Summary: In this study, an asymmetric organocatalytic reaction was developed for the first time, enabling the remote 1,10-addition of alkynyl indole imine methides generated in situ from alpha-(6indolyl) propargylic alcohols with thiazolones. The reaction yielded axially chiral tetrasubstituted allenes featuring vicinal sulfur-containing quaternary carbon stereocenters, with high yields and excellent stereoselectivities. The scalability of the reaction and the chemical transformations of the 1,10-adduct were also investigated. Control experiments and DFT calculations were conducted to elucidate the reaction mechanism.
Article
Chemistry, Multidisciplinary
Yunnan Xu, Delong Liu, Yu Deng, Yi Zhou, Wanbin Zhang
Summary: An asymmetric hydrogenation of 3-benzoylaminocoumarins was achieved for the first time using the BridgePhos-Rh catalytic system, providing chiral 3-amino dihydrocoumarins in high yields and with excellent enantioselectivities. The relationship between the enantioselectivities of the hydrogenations and the dihedral angles and the resulting pi-pi stacking effects of the BridgePhos-Rh complexes, determined by X-ray diffraction analysis, was discussed. The corresponding hydrogenated products allow for many transformations, providing several chiral skeletons with important physiological and pharmacological activities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Biochemistry & Molecular Biology
Dae Young Kim
Summary: A one-pot strategy has been developed for the synthesis of multisubstituted 3,4-dihydrocoumarins with high yields and excellent diastereoselectivity. This approach involves C-H oxidation and cyclization cascade reactions of 2-alkyl phenols and oxazolones in the presence of silver oxide and p-toluenesulfonic acid as catalysts.
Review
Chemistry, Applied
Yuxue Cao, Guodu Liu
Summary: Chiral phosphoric acid has been a crucial catalyst in chemical synthesis for over five decades. However, a revolutionary approach using photocatalytic excitation of molecules to generate free radicals has emerged in recent years, surpassing the limitations of traditional organic synthesis methods. A significant area of research focuses on chiral phosphoric acid synergistic photocatalysis for enantioselective chemical synthesis, utilizing a bifunctional hydrogen-bonding catalyst.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Guangmiao Wu, Tao Li, Fuhai Liu, Yulong Zhao, Shiqiang Ma, Shouchu Tang, Xingang Xie, Xuegong She
Summary: An efficient thiourea-catalyzed 1,6-conjugate addition of indoles to para-quinone methides (p-QMs) was developed, where p-QMs were activated by a weak hydrogen-bond effect. The reaction features mild conditions and a wide substrate scope, allowing for the synthesis of a series of C-3 bisaryl methine substituted indoles in high yield.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Organic
Jing He, Deyuan Meng, Dong Yeon Lee, Jaesook Yun
Summary: We report a ligand-free copper-catalyzed 1,6-addition reaction of alpha-borylalkyl copper species with para-quinone methides. The reaction, catalytically generated from gem-diborylalkanes, shows good yield for various para-quinone methides and substituted gem-diborylalkanes with a catalytic amount of CuI. This catalytic system provides a cost-effective process with good functional group tolerance under mild conditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Kai-Xue Xie, Zhi-Pei Zhang, Xin Li
Article
Chemistry, Multidisciplinary
Weiqiang Chen, Huaquan Fang, Kaixue Xie, Martin Oestreich
CHEMISTRY-A EUROPEAN JOURNAL
(2020)
Article
Chemistry, Multidisciplinary
Huaquan Fang, Kaixue Xie, Sebastian Kemper, Martin Oestreich
Summary: The study demonstrates that Tris(pentafluorophenyl)borane catalyzes the two-fold C(sp(3))-H silylation of various trialkylamine derivatives with dihydrosilanes, resulting in the formation of 4-silapiperidines in decent yields. The reaction cascade involves amine-to-enamine dehydrogenation at two alkyl residues and two electrophilic silylation reactions of those enamines, one inter- and one intramolecular.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Kaixue Xie, Martin Oestreich
Summary: Readily available cyclohexa-2,5-dien-1-ylcarbonyl chloride derivatives were used as stable HCl surrogates for transfer hydrochlorination of alkenes and alkynes. B(C6F5)(3) facilitated the stepwise fragmentation of acyl chlorides, allowing the addition of HCl across C-C double and triple bonds with Markovnikov selectivity at room temperature.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
