A Versatile Enantioselective Catalytic Cyclopropanation‐Rearrangement Approach to the Divergent Construction of Chiral Spiroaminals and Fused Bicyclic Acetals. Issue 43 (20th August 2020)

• Record Type: Journal Article
• Authors: Zhou, Li; Yan, Wen‐Guang; Sun, Xiu‐Li; Wang, Lijia; Tang, Yong
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 43(2020)
• Page Start: 18964
• Page End: 18969
• Publication Date: 2020-08-20
• Subjects: bicyclic acetal -- copper catalyst -- cyclopropanation -- enantioselective -- spiroaminal; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202007068
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A highly enantioselective synthesis of various chiral heterobicyclic molecules including spiroaminals and fused bicyclic acetals has been developed via a chiral copper catalyzed cyclopropanation‐rearrangement (CP‐RA) approach under mild reaction conditions. Remarkably, the asymmetric CP‐RA for exocyclic vinyl substrates without a pro‐stereogenic carbon at the β‐position has been realized for the first time and a broad substrate scope with excellent results (33 examples; 34–99 % yields; >95/5 dr and 91–99 % ee ) has been achieved. An application of a successive enantioselective CP‐RA approach was also described, providing a concise access to complex chiral heteropolycycles. Abstract : An effective divergent synthesis of chiral spiroaminals and fused bicyclic acetals has been realized in up to 99 % yield with up to 99 % ee via an unusual enantioselective cyclopropanation‐rearrangement process.