Palladium(II)-catalyzed catalytic aminocarbonylation and alkoxycarbonylation of terminal alkynes: regioselectivity controlled by the nucleophiles
作者:Rami Suleiman、Jimoh Tijani、Bassam El Ali
DOI:10.1002/aoc.1585
日期:——
the selectivity towards the gem or trans unsaturated esters or amides with these nucleophiles. The effects of the type of palladium catalysts, the type of ligands, the amount of dppb and the solvents were carefully studied. With diisobutylamine (2b1), excellent regioselectivity towards the 2‐acrylamides (gem isomer, 3ab1) was almost always observed, while trans‐α,β‐unsaturated esters 4ac1 was the predominant
末端炔烃氨基羰基和烷氧羰基的反应发生平稳且高效地使用的催化剂体系的Pd(OAC)2 -dppb- p -TsOH CH 3 CN CO相对温和的实验条件下。使用两种不同的亲核试剂(醇和胺)对催化体系进行了测试和优化。苯乙炔(1a)被认为是炔烃,而二异丁胺(2b 1)和甲醇(2c 1)被认为是亲核试剂。结果显示1a的转化率和对宝石或反式的选择性的显着差异这些亲核试剂的不饱和酯或酰胺。仔细研究了钯催化剂类型,配体类型,dppb量和溶剂的影响。使用二异丁胺(2b 1),几乎总是观察到对2-丙烯酰胺(宝石异构体3ab 1)具有极好的区域选择性,而反式α,β-不饱和酯4ac 1是以甲醇(2c 1)为亲核试剂的主要产物。。这种对反应选择性的显着敏感性表明了这些羰基化反应的两种不同的可能机理。版权所有©2009 John Wiley&Sons,Ltd.