A stereocontrolled synthesis of (±)-xenovenine via a scandium(III)-catalyzed internal aminodiene bicyclization terminated by a 2-(5-ethyl-2-thienyl)ethenyl group

A highly diastereoselective binary hydroamination of a 5-amino-1,8-diene containing a 2-(5-ethyl-2-thienyl)ethenyl terminator has been utilized in an efficient synthesis of (±)-xenovenine (1). A pronounced rate enhancement was observed for cyclization onto the 2-(heteroaromatic)ethenyl group in comparison to a simple 1,2-disubstituted alkene.