Organocatalytic enantio- and diastereoselective synthesis of trifluoro-ethylamine allenoate derivatives containing axial and central chiralities

Herein, we report an example of a stereoselectivec-addition reac-tion of trifluoromethyl ketimines to 1-alkynyl ketones mediatedby an isothiourea, BTM, under mild conditions, which affordedtetrasubstituted allenes with central chiralities in high yields (upto 94% yield), good enantioselectivities (up to 91% ee), and excellentdiastereoselectivities (all420 : 1 dr). In addition, the BTM-catalyzedc-addition reaction was successfully applied to the gram-scale reac-tion, and an unexpected benzopyrrolothiazine derivative was success-fully converted, albeit racemic.