Diamine-mediated N-2-selective beta-selenoalkylation of triazoles with alkenes

A N-2-selective beta-selenoalkylation of 1,2,3-triazoles with alkenes mediated by diamines has been developed. The reaction proceeds presumably via the interaction of diamines with both the triazole moiety and selenium/alkene complex to construct a U-shaped reaction intermediate. This activation mode will block the N-1 position on triazoles and thus favor the N-2-selective selenoamination. This stereospecific anti-addition method enables an efficient N-2-selective b-selenoalkylation of 1,2,3-triazoles under mild and open-air conditions and might find applications in the synthesis of biologically active molecules.