Gold-Catalyzed Asymmetric Intramolecular Cyclization of N-Allenamides for the Synthesis of Chiral Tetrahydrocarbolines

Angew Chem Int Ed Engl. 2017 Dec 11;56(50):15905-15909. doi: 10.1002/anie.201709595. Epub 2017 Nov 20.

Abstract

Highly enantioselective gold-catalyzed intramolecular cyclization of N-allenamides was implemented by utilizing a designed chiral sulfinamide phosphine ligand (PC-Phos). This represents the first example of highly enantioselective intramolecular cyclization of N-allenamides. The practicality of this reaction was validated in the total synthesis of (R)-desbromoarborescidine A and formal synthesis of (R)-desbromoarborescidine C and (R)-deplancheine. Moreover, the catalyst system PC-Phos/AuNTf2 proved to be specifically efficient to promote the desymmetrization of N-allenamides in excellent yields with satisfactory ee values.

Keywords: allenamides; cyclization; enantioselectivity; gold; tetrahydrocarboline.

Publication types

  • Research Support, Non-U.S. Gov't