A chemoselective and robust protocol for the γ-oxidation of β,γ-unsaturated amides is reported. In this method, electrophilic amide activation, in a rare application to unsaturated amides, enables a regioselective reaction with TEMPO resulting in the title products. Radical cyclisation reactions and oxidation of the synthesised products highlight the synthetic utility of the products obtained.
报道了一种用于 β,γ-不饱和酰胺的 γ-氧化的化学选择性和稳健的方案。在这种方法中,亲电酰胺活化(在罕见的不饱和酰胺应用中)能够与 TEMPO 进行区域选择性反应,从而产生标题产物。合成产物的自由基环化反应和氧化突出了所得产物的合成效用。
Taming the Carboxyl Group for Directed Carbometalation-Observations on the Use of Anions, Dianions and Ester Enolates
作者:Sandy Desrat、Philip J. Gray、Matthew R. Penny、William B. Motherwell
DOI:10.1002/chem.201403294
日期:2014.6.23
Carboxylate anions, dianions and esterenolates provide simultaneous protection and activation for directed carbometalation reactions. Advantage can be taken of the bis‐carbanionic character of the intermediate for further controlled CC bond forming reactions.
Access to Functionalized <i>E</i>-Allylsilanes and <i>E</i>-Alkenylsilanes through Visible-Light-Driven Radical Hydrosilylation of Mono- and Disubstituted Allenes
作者:Yanyao Cai、Wenxuan Zhao、Shaozhong Wang、Yong Liang、Zhu-Jun Yao
DOI:10.1021/acs.orglett.9b03679
日期:2019.12.20
visible-light-driven radical hydrosilylation of allene has been achieved by using eosin Y as the photocatalyst, with thiol and base as additives. Depending on allenes, two types of adducts with E-selectivity were obtained. It was demonstrated that monosubstituted nonarylated allenes reacted to give linear E-allylsilanes, while 1,3-disubstituted electron-deficient allenes afforded E-alkenylsilanes. A radical mechanism