77014-30-3Relevant articles and documents
Desymmetrizing reductive aldol cyclizations of enethioate derivatives of 1,3-diones catalyzed by a chiral copper hydride
Ou, Jun,Wong, Wing-Tak,Chiu, Pauline
supporting information; experimental part, p. 5971 - 5978 (2012/08/28)
A range of enethioate derivatives of 1,3-diones underwent reductive aldol cyclizations catalyzed by a chiral copper hydride generated in situ from 5 mol% TaniaPhos (SL-T001-1), 5 mol% Cu(OAc)2·H2O, 5 mol% bipyridine and 2.0 equiv. of PhSiH3, to furnish polycyclic β-hydroxythioester products bearing three newly established contiguous stereocenters, with >98:2 dr and in up to 94% yield and 98% ee. The use of an amine such as bipyridine or 2,6-lutidine as additive results in an increase of the overall reaction rate. The major bicyclic aldol product has all substituents cis and can be rationalized by a reductively generated (Z)-enolate reacting with the dione via a cyclic transition state.
