Synthesis of the first examples of 1H- and 4H-1,2,4,3λ³-triazaphospholes via unexpected ring-contraction reactions

Abstract

The reaction of the Schiff bases of benzamidrazone or diaminomaleonitrile with bis(dimethylamino)chlorophosphine or tris(dimethylamino)phosphine affords new 1H, 2H-, or 4H-1,2,4,3λ3-triazaphospholes or 1,3,2λ3-diazaphospholes with the formation of triaza- or diaza-phosphorines as intermediates.