Tandem Oxidation Processes for the Preparation of Functionalized Cyclopropanes
作者:Magalie F. Oswald、Steven A. Raw、Richard J. K. Taylor
DOI:10.1021/ol0483394
日期:2004.10.1
[reaction: see text] A novelmanganese dioxide-mediated tandem oxidation process (TOP) has been developed which allows the direct conversion of allylicalcohols into cyclopropanes, the intermediate aldehydes being trapped in situ with a stabilized sulfur-ylide. This methodology has been applied successfully to a variety of allylicalcohols and to a formal synthesis of the simple, naturally occurring
Carbene-catalyzed activation of cyclopropylcarbaldehydes for mannich reaction and δ-lactam formation: remote enantioselecitvity control and dynamic kinetic asymmetric transformation
作者:Jie Lv、Jun Xu、Xuling Pan、Zhichao Jin、Yonggui Robin Chi
DOI:10.1007/s11426-021-9989-1
日期:2021.6
An N-heterocyclic carbene (NHC)-catalyzed enantioselective Mannich reaction of the remote γ-carbon of cyclopropylcarbaldehydes is disclosed for the first time. Diastereo- and enantiomerically enriched multicyclic δ-lactam compound is afforded as the main product from 8 possible stereo-specific isomers through dynamickineticasymmetrictransformation (DYKAT) processes. Multiple chiral functional molecules
NHC-Catalyzed Chemoselective Reactions of Enals and Cyclopropylcarbaldehydes for Access to Chiral Dihydropyranone Derivatives
作者:Yingling Nong、Chen Pang、Kunpeng Teng、Sheng Zhang、Qian Liu
DOI:10.1021/acs.joc.3c01171
日期:2023.10.6
An N-heterocyclic carbene (NHC)-catalyzed chemoselective activation reaction of 1-cyclopropylcarbaldehydes and α-alkynyl enals is reported. NHC selectively catalyzes 1-cyclopropylaldehydes, followed by a [2 + 4] cycloaddition reaction with α-alkynyl enals. The target dihydropyranone derivatives bearing different substituents and substitution patterns can be obtained in good to excellent yields with