Enantioselective decarboxylative Mannich reaction of β-keto acids with C-alkynyl N-Boc N,O-acetals: access to chiral β-keto propargylamines

The chiral keto-substituted propargylamines are an essential class of multifunctional compounds in the field of organic and pharmaceutical synthesis and have attracted considerable attention, but the related synthetic approaches remain limited. Therefore, a concise and efficient method for the enantioselective synthesis of beta-keto propargylamines via chiral phosphoric acid-catalyzed asymmetric Mannich reaction between beta-keto acids and C-alkynyl N-Boc N,O-acetals as easily available C-alkynyl imine precursors has been demonstrated here, affording a broad scope of beta-keto N-Boc-propargylamines in high yields (up to 97%) with generally high enantioselectivities (up to 97 : 3 er).

Automated summary

This study demonstrated a concise and efficient method for enantioselective synthesis of beta-keto propargylamines via chiral phosphoric acid-catalyzed asymmetric Mannich reaction. The method provides a wide scope of products with high yields and generally high enantioselectivities.