Remote Construction of Chiral Vicinal Tertiary and Quaternary Centers by Catalytic Asymmetric 1,6-Conjugate Addition of Prochiral Carbon Nucleophiles to Cyclic Dienones

摘要

An unprecedented remote construction of chiral vicinal tertiary and quaternary centers by a catalytic asymmetric 1,6-conjugate addition of prochiral carbon nucleophiles to cyclic dienones has been developed. Both 5Hoxazol- 4-ones and 2-oxindoles were found to be very efficient carbon nucleophiles in this reaction at a remote position, giving products with excellent enantio-and diastereoselectivities (up to 99% ee and > 19: 1 d. r. for 5H-oxazol-4-ones and up to 97% ee and > 19: 1 d. r. for 2-oxindoles).