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Enantioselective Construction of Aryl‐Substituted All‐Carbon Quaternary Stereocenters by Using Tertiary Amine–Thiourea‐Catalyzed Michael Additions
Author(s) -
Chen Peng,
Bao Xu,
Zhang LeFen,
Liu GuoJie,
Jiang YiJun
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.201501420
Subject(s) - stereocenter , michael reaction , enantioselective synthesis , enantiopure drug , chemistry , thiourea , organic chemistry , aryl , organocatalysis , catalysis , steric effects , amine gas treating , combinatorial chemistry , alkyl
Abstract A catalytic enantioselective synthetic strategy for the aryl‐substituted all‐carbon quaternary stereocenters of bioactive hydrodibenzofuran alkaloids was achieved by the Michael addition reaction of α‐cyano ketones and acrylates using a chiral tertiary amine–thiourea catalyst. This method can tolerate steric bulkiness and multiple functional groups, and 32 Michael adducts were prepared in good to excellent yields with moderate to good enantioselectivities. The enantiopurity of the products could also be enriched up to 99 % ee after one recrystallization. This enantioselective Michael addition features a low cost, metal‐free, and easily operable procedure that can provide multifunctionalized enantiopure Michael adducts on a four‐gram scale and supply sufficient amounts of potential precursors for a number of hydrodibenzofuran natural products.