Phosphine-catalyzed intramolecular Rauhut-Currier reaction: enantioselective synthesis of hydro-2H-indole derivatives.

A highly enantioselective intramolecular Rauhut-Currier reaction catalyzed by a multifunctional chiral aminophosphine catalyst was reported. A series of hydro-2H-indole derivatives that bear an all-carbon quaternary center were obtained in high yields (up to 94%), and excellent diastereo- and enantioselectivities (up to >20 : 1 dr and >99% ee). And this reaction could be performed on a gram scale using 2 mol% catalyst loading.