Highly Enantioselective Alkylation Reaction of Enamides by Brønsted-Acid Catalysis
作者:Qi-Xiang Guo、Yun-Gui Peng、Jin-Wei Zhang、Liu Song、Zhang Feng、Liu-Zhu Gong
DOI:10.1021/ol901892s
日期:2009.10.15
The H-8-BINOL-derived, phosphoric acid catalyzed, highly enatioselective alkylation reaction of enamides with indolyl alcohols has been described. A phosphoric acid derived from H8-BINOL enabled an asymmetric alpha-alkylation of enamides with indolyl alcohols to give beta-aryl 3-(3-indolyl)propanones in high yields (up to 96%) and with excellent enantioselectivity (up to 96% ee).
A highly efficient route to C-3 alkyl-substituted indoles via a metal-free transfer hydrogenation
A highly efficient route to C-3 alkyl-substituted indoles via completely metal-free catalytic transfer hydrogenation of 3-indolemethanols was developed. This process proceeds via vinylogous iminium intermediates formed in situ in the presence of Brønsted acids, and Hantzsch ester is used as the reductant. The reduction works extremely well with a large substrate scope, and the yields exceed 90% in
Simple steps, complex result: Consecutive organo‐catalyzed reactions of 3‐indolylmethanol compounds with aldehydes and N‐protected indoles lead to the formation of structurally complex cyclopenta[b]indoles (see scheme, Bn=benzyl). These one‐pot multistep reactions have a broad substrate scope and give the products in high yields, and with excellent diastereoselectivities and enantioselectivities.
简单的步骤,复杂的结果:3-吲哚基甲醇化合物与醛和N-保护的吲哚的连续有机催化反应会导致结构上复杂的环戊[ b ]吲哚的形成(参见方案,Bn =苄基)。这些一锅多步反应具有广泛的底物范围,可高收率地提供产物,并具有出色的非对映选择性和对映选择性。