ja8b13390_si_002.cif (763.83 kB)

Bis(imido)vanadium(V)-Catalyzed [2+2+1] Coupling of Alkynes and Azobenzenes Giving Multisubstituted Pyrroles

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posted on 07.02.2019, 00:00 by Kento Kawakita, Evan P. Beaumier, Yuya Kakiuchi, Hayato Tsurugi, Ian A. Tonks, Kazushi Mashima
The combination of VCl3(THF)3 and N,N-bis­(trimethylsilyl)­aniline (1a) is an efficient catalyst for the [2+2+1] coupling reaction of alkynes and azobenzenes, giving multisubstituted pyrroles. A plausible reaction mechanism involves the generation of a mono­(imido)­vanadium­(III) species as an initiation step, where 1a served as an imido source with concomitant release of 2 equiv of ClSiMe3, followed by a reaction with azobenzene to form a catalytically active bis­(imido)­vanadium­(V) species via NN bond cleavage.