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Chiral Squaramide‐Catalyzed Sulfa‐Michael/Aldol Cascade for the Asymmetric Synthesis of Spirocyclic Tetrahydrothiophene Chromanone Derivatives
Author(s) -
Zhao BoLiang,
Liu Lei,
Du DaMing
Publication year - 2014
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.201402889
Subject(s) - tetrahydrothiophene , squaramide , aldol reaction , stereocenter , chemistry , bifunctional , michael reaction , catalysis , organocatalysis , cascade reaction , enantioselective synthesis , organic chemistry , combinatorial chemistry , stereochemistry
Abstract A bifunctional squaramide‐catalyzed sulfa‐Michael/aldol cascade reaction between benzylidenechroman‐4‐ones and 1,4‐dithiane‐2,5‐diol with a low catalyst loading has been developed. This reaction constitutes a facile asymmetric synthesis of chiral spirocyclic tetrahydrothiophene chromanone derivatives with three contiguous stereocenters in high to excellent yields (up to 99 %) and with high enantioselectivities (up to 92 % ee ). Additionally, a remarkable temperature effect on reaction efficiency was observed and gram‐scale syntheses were found to proceed smoothly with the same efficiency as smaller scale reactions.