A new, practical route to enoxysilanes is described from simple enolizable aldehydes or ketones, using the trimethylchlorosilane-sodium iodide—tertiary amine reagent in acetonitrile. From certain aldehydes, an onium intermediate has been isolated. A conformational study of this onium intermediate and a thermal unimolecular syn-elimination process may explain the stereoselectivity of the reaction. Such
Kinetic resolution in asymmetric anti aldol reactions of branched and straight chain racemic 2-phenylsulfanyl aldehydes: asymmetric synthesis of cyclic ethers and lactones by phenylsulfanyl migration
作者:Kelly Chibale、Stuart Warren
DOI:10.1039/p19960001935
日期:——
The kinetic resolution of branched and straight chain 2-phenylsulfanyl aldehydes by the Lewis acid-catalysed asymmetric anti aldol reaction followed by reduction to single enantiomers of 1,3-diols and/or acid-catalysed cyclisation with PhS migration provides a route to enantiomerically pure cyclic ethers and lactones with full stereochemical control.
Mixed Monosilyl Acetals and Catalyst-Dependent Chemoselective Mukaiyama Aldol Reactions
作者:Sun Min Kim、Hye Sung Yang、Heesung Eum、Hyun-Joon Ha、Jung Woon Yang
DOI:10.1002/chem.201704456
日期:2017.11.21
construction of a mixed monosilyl acetal as a new and synthetically valuable functional group by mixing an aldehyde, sodium tert‐butoxide, and trimethylsilyl azide. We also demonstrate a catalyst‐dependent chemoselective reaction between mixed monosilyl acetals and silylketeneacetals through Mukaiyama aldol reactions to give different structures of O‐protected β‐hydroxy esters in excellent yields with high