这里描述的是路易斯酸性硼烷催化剂介导的α,β-不饱和醛的还原胺化/氢化硅烷化级联。本反应系统提供了一种单罐合成路线,可通往其他先前催化无法达到的β-甲硅烷基化仲胺。对亚胺的甲硅烷基化还原进行的比较1 H NMR研究表明,伯胺反应物的空间体积极大地影响了催化效率和区域选择性。该策略适用于广泛的底物,并适用于一锅克级合成。此外,还发现非对映选择性地引入β-甲硅烷基是可行的(dr高达71:29)。
A Direct Phosphine-Mediated Synthesis of Pyrroles from Acid Chlorides and α,β-Unsaturated Imines
作者:Yingdong Lu、Bruce A. Arndtsen
DOI:10.1021/ol900185n
日期:2009.3.19
A one-step method to assemble pyrroles fromα,β-unsaturatedimines and acid chlorides has been developed. This reaction is mediated by triphenylphosphine, which eliminates phosphine oxide to allow cyclization. This reaction has been employed to access a diverse range of pyrroles via modulation of the two building blocks and applied as well to the synthesis of lukianol A.
Copper-catalyzed alkenylation of novel <i>N</i>-iodoarylated allylic ketopiperazinonates with unactivated alkenes
作者:Timothy K. Beng、Antonio Moreno
DOI:10.1039/c9nj06178a
日期:——
N-Aryl-substituted piperazines constitute the core of several pharmacologically pertinent targets such as the antidepressant trintellix. We herein demonstrate that novel N-iodoaryl-substituted allylic ketopiperazinonates are amenable to efficient CuBr-catalyzed alkenylation with simple alkenes to afford N-stilbeno or styrenyl piperazinederivatives.
Reactions of Zirconocene–1-Aza-1,3-diene Complexes with Acyl Cyanides: Substrate-Dependent Synthesis of Acyl- or Non-Acyl-Substituted Pyrroles
作者:Meijun Xiong、Shasha Yu、Xin Xie、Shi Li、Yuanhong Liu
DOI:10.1021/acs.organomet.5b00801
日期:2015.12.14
Insertion of acyl cyanides into azazirconacydopentenes derived from 1,3-azadienes has been described, which affords acyl- or non-acyl-substituted pyrroles upon acidic quenching. These reactions are initialized through C=O insertion into the azazirconacycle to afford seven-membered oxaazazirconacycles. In the cases of 1,4- or 1,2,4-substituted azadienes, addition of a second molecule of acyl cyanide followed by cyclization upon acidic quenching leads to acyl-substituted pyrroles. In the cases of 1,3,4-substituted azadienes, the addition of a second molecule of acyl cyanide cannot proceed due to the steric hindrance caused by the R-3 group on the zirconium intermediate. Acidic quenching of the resulting zirconium intermediate affords non-acyl-substituted pyrroles.