A palladium-catalyzed 1,4-enyne synthesis was developed based the decarboxylative coupling of acetylides with allyl electrophiles. Stereochemical studies have implicated palladium-allyl-acetylides as intermediates. Thus, decarboxylative metalation was established as an environmentally benign alternative to transmetalation from alkynyl tin reagents.
Nickel-catalyzed allylation of lithium 1-alkynyl(trialkoxy)borates with 1,3-disubstituted allyl carbonates
作者:H Chen
DOI:10.1016/s0022-328x(00)00164-9
日期:2000.5.29
alkynylborates with 1,3-disubstitued allylcarbonates was studies. It was found that nickel complexes readily catalyzed the reaction giving normal coupling products in good to excellent yields. The nickel complexes of dppe or dppen revealed a higher catalytic activity than that of NiCl2(PPh3)2 or NiCl2(dppf). This is a substrate-controlled reaction with high regioselectivity. The asymmetric cross-coupling