Ba black sheep: We have developed novel barium/binol catalysts prepared from alkaline earth metal amides and chiral binaphthol ligands. These catalysts effectively promoted the asymmetric Friedel–Crafts–typealkylationreactions of indoles with chalconederivatives. This is the first example of asymmetric Friedel–Crafts–typealkylationreactionsusingchiral Brønsted bases.
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).