established, asymmetric hydrogenation of challenging tetrasubstituted α,β‐unsaturatedcarboxylicacids is rarely reported. We demonstrate enantioselective hydrogenation of cyclic and acyclic tetrasubstituted α,β‐unsaturatedcarboxylicacids via cobalt(II) catalysis. This protocol showed broad substrate scope and gave chiral carboxylicacids in good yields with excellent enantiocontrol (up to 98 % yield and
A New General Method for the Asymmetric Synthesis of 4-Alkyl-3-aryl-1,2,3,4-tetrahydroisoquinolines
作者:Jose L. Vicario、Dolores Badía、Esther Domínguez、Luisa Carrillo
DOI:10.1021/jo982008l
日期:1999.6.1
A highly enantioselective method for the synthesis of 4-alkyl substituted 1,2,3,4-tetrahydroisoquinolines is reported. The key step relies on the asymmetric synthesis of alpha-alkylarylacetic acids by alkylation of their corresponding amides employing (S,S)-(+)-pseudoephedrine as chiral inductor. Subsequent Friedel-Crafts acylation, stereocontrolled reductive amination and Pictet-Spengler cyclization