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Formal Asymmetric Catalytic Thiolation with a Bifunctional Catalyst at a Water–Oil Interface: Synthesis of Benzyl Thiols
Author(s) -
Guo Wengang,
Wu Bo,
Zhou Xin,
Chen Ping,
Wang Xu,
Zhou YongGui,
Liu Yan,
Li Can
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201409894
Subject(s) - squaramide , chemistry , moiety , bifunctional , enantioselective synthesis , catalysis , bifunctional catalyst , stereoselectivity , organic chemistry , reactivity (psychology) , organocatalysis , amine gas treating , combinatorial chemistry , solvent , medicine , alternative medicine , pathology
The enantioselective conjugated addition of tritylthiol to in situ generated ortho ‐quinone methides ( o ‐QMs) is catalyzed by an acid–base bifunctional squaramide organocatalyst. The transformation proceeds with high yield (up to 99 %) and stereoselectivity (up to 97:3 e.r.) using water as solvent under mild conditions. The catalyst system provides a new strategy for the synthesis of optically active benzyl mercaptans. Control experiments suggested that o ‐QMs are generated by the tertiary amine moiety of the squaramide organocatalyst and that the water–oil biphase is crucial for achieving high reactivity and stereoselectivity.