A convergent method for the stereoselective synthesis of trisubstituted alkenes
摘要:
A method for the stereoselective, convergent synthesis of trisubstituted alkenes has been developed. The procedure features the synthesis of allylic alcohols 9 by coupling an aldehyde with a vinyl organometallic reagent. Treatment of 9 with carbon disulfide and methyl iodide gave the intermediate allylic xanthates 10 that underwent facile [3,3]-sigmatropic rearrangement to give the dithiocarbonates 11 and 12, radical reduction of which gave the (E)-alkenes 13 as the major products.
作者:Christine Zioudrou、Irene Moustakali-Mavridis、Polyxene Chrysochou、Gerasimos J. Karabatsos
DOI:10.1016/0040-4020(78)87014-8
日期:1978.1
The diastereomeric product ratios from reactions involving the addition of various reagents to the carbonyl of φCH3HC-COR compounds varies over a wide range. This variation is interpreted as due partly to changes in the structure of the diastereomeric transition states with changes in the size of R. For example, when R is smaller than the φCH3HC group the diastereomeric product ratios are close to
A convergent method for the stereoselective synthesis of trisubstituted alkenes
作者:Stephen F. Martin、Dilon Daniel、Robert J. Cherney、Spiros Liras
DOI:10.1021/jo00035a004
日期:1992.4
A method for the stereoselective, convergent synthesis of trisubstituted alkenes has been developed. The procedure features the synthesis of allylic alcohols 9 by coupling an aldehyde with a vinyl organometallic reagent. Treatment of 9 with carbon disulfide and methyl iodide gave the intermediate allylic xanthates 10 that underwent facile [3,3]-sigmatropic rearrangement to give the dithiocarbonates 11 and 12, radical reduction of which gave the (E)-alkenes 13 as the major products.
Rhodium‐Catalyzed Regio‐ and Diastereoselective [3+2] Cycloaddition of <i>gem</i>‐Difluorinated Cyclopropanes with Internal Olefins
作者:Yaxin Zeng、Ying Xia
DOI:10.1002/anie.202307129
日期:2023.8.7
A rhodium-catalyzed [3+2] cycloaddition reaction between readily available gem-difluorinated cyclopropanes and internal olefins has been developed, providing a wide range of multisubstituted gem-difluorinated cyclopentanes. This reaction shows an example where the “CF2” motif can be kept upon ring extension. The process is atom-economic and allows to reach numerous gem-difluorinated cyclopentanes with