The Regio‐ and Stereospecific Intermolecular Dehydrative Alkoxylation of Allylic Alcohols Catalyzed by a Gold(I) N‐Heterocyclic Carbene Complex
作者:Paramita Mukherjee、Ross A. Widenhoefer
DOI:10.1002/chem.201203987
日期:2013.3.4
AgClO4 catalyzes the intermolecular dehydrative alkoxylation of primary and secondary allylic alcohols with aliphatic primary and secondary alcohols to form allylic ethers. These transformations are regio‐ and stereospecific with preferential addition of the alcohol nucleophile at the γ‐position of the allylic alcohol syn to the departing hydroxyl group and with predominant formation of the E stereoisomer
[AuCl(IPr)] (IPr=1,3-双(2,6-二异丙基苯基)咪唑-2-亚基) 和 AgClO 4的 1:1 混合物催化伯烯丙醇和仲烯丙醇与脂肪族伯醇的分子间脱水烷氧基化和仲醇形成烯丙醚。这些转化是区域和立体特异性的,烯丙醇顺式的 γ 位上的醇亲核试剂优先加成到离开的羟基上,并主要形成E立体异构体。次要α区域异构体主要通过二次反应歧管形成,涉及最初形成的烯丙醚的区域选择性γ-烷氧基化,而不是通过烯丙醇的直接α-烷氧基化。