The C–C bond cleavage/coupling of 2-(azetidin-3-ylidene)acetates with aryl boronic acids catalyzed by a rhodium complex was studied with a “conjugate addition/β-C cleavage/protonation” strategy.
Synthesis of Dialkyl Alkoxycarbonylmethanephosphonates (Alkyl Dialkoxyphosphinylacetates) using Phase-Transfer Catalysis
作者:WEIZHEN Ye、XIUGAO Liao
DOI:10.1055/s-1985-31418
日期:——
A facile method for the preparation of dialkyl alkoxycarbonylmethanephosphonates under phase-transfer catalysis is described.
本文描述了一种在相转移催化下制备二烷基烷氧羰基亚甲基膦酸酯的简易方法。
Highly (<i>E</i>)-Selective Wadsworth−Emmons Reactions Promoted by Methylmagnesium Bromide
作者:Timothy D. W. Claridge、Stephen G. Davies、James A. Lee、Rebecca L. Nicholson、Paul M. Roberts、Angela J. Russell、Andrew D. Smith、Steven M. Toms
DOI:10.1021/ol802212e
日期:2008.12.4
An experimentally simple protocol for the very highly (E)-selective Wadsworth-Emmonsreaction [(E):(Z) selectivities in excess of 180:1 in some cases] of a range of straight-chain and branched aliphatic, substituted aromatic, and base-sensitive aldehydes via reaction with an alkyl diethylphosphonoacetate and MeMgBr is reported.
The carboalkoxyallylsilane terminator for biomimetic polyene cyclizations. A route to 21-hydroxyprogesterone types
作者:William S. Johnson、Clive Newton、Stephen D. Lindell
DOI:10.1016/s0040-4039(00)85389-7
日期:——
Polyene 3 containing a carboalkoxyallylsilane terminator was cyclized to give pro-steroid 6 in 68–75% yield. Unequivocal proof for the structure of 6 was obtained by conversion to the racemic form of the natural cortical hormone 17-desoxycorticosterone (15).