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Palladium‐Catalyzed Enantioselective Addition of Chiral Metal Enolates to In Situ Generated ortho ‐Quinone Methides
Author(s) -
Göricke Fabian,
Schneider Christoph
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201809692
Subject(s) - stereocenter , electrophile , catalysis , nucleophile , enantioselective synthesis , chemistry , palladium , oxazoline , in situ , quinone , combinatorial chemistry , organic chemistry
We describe herein a conceptually novel, cooperative Brønsted acid/base catalyzed process for the conjugate addition of cyclic β‐keto esters to ortho ‐quinone methides both generated in situ. Upon hemiacetalization, densely functionalized chiral chromans with two adjacent quaternary and additionally a tertiary stereogenic center were obtained with very good diastereoselectivity (up to >95:5 d.r.) and typically excellent enantioselectivity (up to >99 % ee ). The striking feature and key to success is the dual catalytic activation of both nucleophile and electrophile in two separate cycles with a single chiral catalyst.