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
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.
Construction of the A–B–C Ring of Simplicissin through an Oxidative Dearomatization/Iodination/[3+2] Annulation Cascade
作者:Ziwei Zhang、Zezhong Sun、Jianing Song、Hao Guo、Yunxia Wang、Xiangdong Hu
DOI:10.1021/acs.orglett.3c03464
日期:2023.12.8
analogues. On the basis of the development of an oxidative dearomatization/iodination/[3+2] annulationcascade, a concise synthetic pathway to the A–B–C ring of simplicissin has been successfully established, and the substrate generality of the novel oxidative dearomatization/iodination/[3+2] annulationcascade has been checked.