Efficient synthesis of 2,5-disubstituted tetrazoles via the Cu2O-catalyzed aerobic oxidative direct cross-coupling of N-H free tetrazoles with boronic acids.

We present a new protocol that allows for the synthesis of 2,5-disubstituted tetrazoles via the direct coupling of N-H free tetrazoles and low toxic boronic acids in the presence of only a catalytic amount of Cu(2)O (5 mol%) as catalyst and 1 atm of environmentally benign O(2) as oxidant, without the need for other additives. This method represents a simple, green, and atom-efficient synthesis of 2,5-disubstituted tetrazoles.