Direct asymmetric N-propargylation of indoles and carbazoles catalyzed by lithium SPINOL phosphate.

ABSTRACT: Catalytic asymmetric functionalization of the N-H groups of indoles and carbazoles constitutes an important but less developed class of reactions. Herein, we describe a propargylation protocol involving the use of a lithium SPINOL phosphate as the chiral catalyst and our recently developed C-alkynyl N,O-acetals as propargylating reagents. The direct asymmetric N-propargylation of indoles and carbazoles provides hitherto inaccessible N-functionalized products. Notably, the efficiency of the system allows reactions to be run at a very low catalyst loading (as low as 0.1?mol%). Mechanistic information about the titled reaction is also disclosed. This study represents an advance in the direct asymmetric functionalization of the N-H bonds of indoles and carbazoles, and additionally expands on the application of chiral alkali metal salts of chiral phosphoric acids in asymmetric catalysis.

SUBMITTER: Wang Y 

PROVIDER: S-EPMC6957506 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature