N'-dioxide-Sc(III) complex catalysts. The BV oxidations of prochiral cyclohexanones and cyclobutanones afforded series of optically active ε- and γ-lactones, respectively, in up to 99% yield and 95% ee. Meanwhile, the kinetic resolution of racemic 2-arylcyclohexanones was also realized via an abnormal BV oxidation. Enantioenriched 3-aryloxepan-2-ones, whose formation is counter to the migratoryaptitude, were
The Silicon–Hydrogen Exchange Reaction: A Catalytic σ-Bond Metathesis Approach to the Enantioselective Synthesis of Enol Silanes
作者:Hui Zhou、Han Yong Bae、Markus Leutzsch、Jennifer L. Kennemur、Diane Bécart、Benjamin List
DOI:10.1021/jacs.0c06677
日期:2020.8.12
stoichiometric chiral reagents. We now describe a catalytic approach in which strongly acidic and confined imidodiphosphorimidates (IDPi) catalyze highly enantioselective interconversions of ketones and enol silanes. These “silicon–hydrogen exchange reactions” enable access to enantiopure enol silanes via tautomerizing σ-bond metatheses, either in a deprotosilylative desymmetrization of ketones with allyl
Cobalt-Catalyzed Desymmetric Isomerization of Exocyclic Olefins
作者:Xufang Liu、Xianle Rong、Shihan Liu、Yu Lan、Qiang Liu
DOI:10.1021/jacs.1c11343
日期:2021.12.15
Chiral cyclic olefins, 1-methylcyclohexenes, are versatile building blocks for the synthesis of pharmaceuticals and natural products. Despite the prevalence of these structural motifs, the development of efficient synthetic methods remains an unmet challenge. Herein we report a novel desymmetric isomerization of exocyclicolefins using a series of newly designed chiral cobalt catalysts, which enables
Desymmetrizing Isomerization of Alkene via Thiazolinyl Iminoquinoline Cobalt Catalysis
作者:Wenbo Liu、Yushan Zheng、Yihui Mao、Jieping Chen、Xiang Ren、Zhaoyang Cheng、Zhan Lu
DOI:10.1021/acs.orglett.1c04237
日期:2022.2.11
1-methylcyclohexene derivatives with good yields and enantioselectivities. A novel chiral thiazolinyl iminoquinoline ligand and its cobalt complex were designed and synthesized to control the establishment of tertiary or quaternary carbon centers at a remote position. This protocol is operationally simple, and a model for the stereochemical outcome has been proposed.
Copper-Catalyzed Enantioselective Hydrosilylation of Allenes to Access Axially Chiral (Cyclohexylidene)ethyl Silanes
作者:Shu Li、Jian-Lin Xu、Yun-He Xu
DOI:10.1021/acs.orglett.2c02359
日期:2022.8.19
A novel strategy of copper-catalyzed regio- and enantioselective hydrosilylation of 4-substituted vinylidenecyclohexanes with silanes was developed. In this protocol, various allenes and silanes were used to afford the corresponding (cyclohexylidene)ethyl silanes in moderate to high yields with good enantioselectivities.