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Tuning the Basicity of a Metal‐Templated Brønsted Base to Facilitate the Enantioselective Sulfa‐Michael Addition of Aliphatic Thiols to α,β‐Unsaturated N ‐Acylpyrazoles
Author(s) -
Ding Xiaobing,
Tian Cheng,
Hu Ying,
Gong Lei,
Meggers Eric
Publication year - 2016
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201501494
Subject(s) - chemistry , enantioselective synthesis , catalysis , iridium , ligand (biochemistry) , metal , michael reaction , brønsted–lowry acid–base theory , organic chemistry , hydrogen bond , base (topology) , medicinal chemistry , combinatorial chemistry , polymer chemistry , molecule , mathematical analysis , biochemistry , receptor , mathematics
The enantioselective addition of aliphatic thiols to α,β‐unsaturated N ‐acylpyrazoles catalyzed by a bis‐cyclometalated iridium(III) complex with fine‐tuned Brønsted basicity was investigated. Good to excellent yields (71–99 %) and enantioselectivities (86–98 % ee ) were achieved at catalyst loadings of 0.2–2.5 mol‐%. In this metal‐templated catalyst design, the metal serves as a structural center and the catalysis is executed by the organic ligand sphere through a combination of proton transfer, hydrogen‐bond formation, and electrostatic interactions.