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Asymmetric epoxidation of chromenes catalyzed by chiral pyrrolidine SalenMn(III) complexes with an anchored functional group
Author(s) -
Zhang Xiang,
Wang DongPing,
Jia YinBao,
Lu XiaoBing,
Wang Hui,
Sun LiCheng
Publication year - 2008
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1450
Subject(s) - chemistry , pyrrolidine , substituent , imidazole , catalysis , pyridine , functional group , enantioselective synthesis , medicinal chemistry , stereochemistry , organic chemistry , polymer
Chiral pyrrolidine SalenMn(III) complexes with an anchored functional group at the N aza ‐substituent in the pyrrolidine backbone were synthesized, and used as catalysts for asymmetric epoxidation of substituted chromenes. The complex 1 with an anchored imidazole as acceptor could effectively catalyze epoxidation of substituted chromenes in the absence of expensive additive 4‐phenyl pyridine N ‐oxide (PPNO) by the coordination of the anchored organic base to the central manganese ion. Complexes 2 and 3 with a quaternary ammonium salt unit at the N aza ‐substituent in the pyrrolidine backbone displayed higher activities than Jacobsen catalyst and the analogous complex 4 without anchored functional group in the aforementioned reaction. Copyright © 2008 John Wiley & Sons, Ltd.