A brief survey on the copper-catalyzed allylation of alkylzinc and Grignard reagents under Barbier conditions

作者：Erdik E^*; Kocoglu M

来源：Applied Organometallic Chemistry, 2006, 20(4): 290-294.

DOI：10.1002/aoc.1052

• alkyl Grignard reagents
• alkylzinc reagents
• allylic coupling
• Barbier-Grignard coupling

The same regioselectivity can be obtained in the Cul catalyzed allylic coupling of -n-butylzinc reagents prepared by either pre-transmetallation or in situ transmetallation of Grignard reagents in the presence of allylic partner and catalyst. n-Butylzinc bromide and di-n-butylzinc undergo gamma-selective allylation whereas tri-n-butylzincate gives preferential a-selectivity. The regioselectivity obtained in the reaction of n-butyl bromide and E-crotyl chloride in the presence of Mg and CuCN is parallel to the coupling of preformed n-buty1magnesium bromide. It is remarkable that the regiochernical outcome of copper catalyzed alkyl-allyl coupling can be controlled by using Grignard reagents prepared under Barbier conditions and alkylzincs prepared by in situ transmetallation.

• 出版日期2006-4