Stereospecificity in the silicon tethered α-(methyl)allylation of aldehydes
作者:Jeremy Robertson、Michael J. Hall、Stuart P. Green
DOI:10.1039/b306920f
日期:——
Heating E- and Z-crotyl(diphenyl)silyloxy aldehydes, in the absence of an added catalyst, results in stereospecific intramolecular allyl transfer with moderate to high stereoselectivity.
Stereospecific α-methallylation of hydroxyaldehydes by silatropic ene cyclisation
作者:Jeremy Robertson、Michael J. Hall、Stuart P. Green
DOI:10.1016/j.tet.2009.01.117
日期:2009.7
We describe the thermal rearrangement of aldehydes bearing an alpha-(allyl- or crotylsilyl)oxy substituent. The transformations are best described mechanistically as intramolecular silatropic ene reactions based on stereoselectivity, kinetic and computed transition state data. The overall process constitutes a stereospecific (meth)allylation of alpha-hydroxyaldehydes, under neutral conditions, in which the hydroxyl protecting group is also the (meth)allylating agent. (C) 2009 Elsevier Ltd. All rights reserved.
Silatropic Carbonyl Ene Cyclizations in the Synthesis of Pseudosugars and Hydroxylated Piperidines
作者:Jeremy Robertson、Petra M. Stafford、Stephen J. Bell
DOI:10.1021/jo050644v
日期:2005.9.1
We describe two applications of silicon-tethered thermal allyl transfer reactions of α-silyloxyaldehydes; formally, these processes can be regarded as silatropic carbonyl enereactions in which the silicon tether is transferred to the aldehyde oxygen concurrent with carbonyl allylation. In the first application, isoserinal substrates, which bear side-chain nitrogen functionality, are elaborated to