An enantioselective Friedel–Craftsalkylation of indoles with β,β-disubstituted nitroalkenes was developed by using a nickel(II) perchlorate–bisoxazoline complex as a catalyst. A range of nitroalkenes and indoles participated in this reaction, affording chiral indole compounds bearing all-carbon quaternary stereocenters in excellent yields and with moderate to good enantioselectivities (up to 80% ee)
Cooperative catalysis: An easily available new type of primary–secondary diamine was synthesized as a highly efficient bifunctionalcatalyst in the asymmetric crossed‐conjugateaddition of β,β‐dialkyl nitroalkenes to α,β‐unsaturated acyclic or cyclic ketones for the first time. The wide substrate scope, excellent yield (up to 96 %) and enantioselectivity (up to 99 % enantiomeric excess (ee)) under
One-pot cascade Michael–Michael–Aldol condensation for diastereoselective synthesis of nitro-substituted cyclohexanes
作者:Yunfeng Chen、Cheng Zhong、Xiaohua Sun、Novruz G. Akhmedov、Jeffrey L. Petersen、Xiaodong Shi
DOI:10.1039/b909766j
日期:——
A one-pot reaction of nitroalkenes and enones was developed for the preparation of nitro-vinyl-substituted cyclohexanes, which could be simply converted into poly-N-heterocycles.
Organocatalyzed Enantioselective
Synthesis of Nitroalkanes Bearing All-Carbon Quaternary
Stereogenic Centers through Conjugate Addition of Acetone Cyanohydrin
作者:Mariafrancesca Fochi、Alfredo Ricci、Luca Bernardi、Francesco Fini
DOI:10.1055/s-2008-1078496
日期:——
The first organocatalyzed phase-transfer enantioselective conjugateaddition of cyanide ion derived from acetone cyanohydrin to β,β'-disubstituted nitroolefins is reported. The reaction leads to the efficient formation of nitroalkanes bearing an all-carbonquaternarystereogeniccenter in up to 72% ee.
报道了第一个有机催化相转移对映选择性共轭加成从丙酮氰醇衍生的氰化物离子到 β,β'-二取代硝基烯烃。该反应导致有效形成具有高达 72% ee 的全碳四元立体中心的硝基烷烃。
Enantioselective Intermolecular Crossed-Conjugate Additions between Nitroalkenes and α,β-Enals through a Dual Activation Strategy
作者:Cheng Zhong、Yunfeng Chen、Jeffrey L. Petersen、Novruz G. Akhmedov、Xiaodong Shi
DOI:10.1002/anie.200805558
日期:2009.2.2
Double the fun: The title reaction was developed by using a Lewis base/iminium activationstrategy (see scheme). The reaction proceeded with excellent yields and ee values, and the products were additionally transformed into a single enantiomer of a substituted pyrrolidine with excellent retention of configuration.