A non-diazo approach to functionalized (2-furyl)-2-pyrrolidines through a cascade reaction of enynal-derived zinc carbenoids with β-arylaminoketones†

This study introduces a cascade approach for synthesizing functionalized (2-furyl)-2-pyrrolidines, showcasing both convergence and remarkable stereoselectivity. This domino process proceeds through an N–H insertion into an enynal-derived metal–carbenoid, followed by an intramolecular aldol reaction to provide pyrrolidines with high diastereoselectivity (98 : 2). This chemistry utilizes Earth-abundant zinc chloride as a catalyst with loading as low as 1 mol%. This method operates under mild conditions and demonstrates high chemoselectivity by accommodating substrates bearing functionalities such as free alcohols, alkenes, and alkynes.