The reaction of 1,2-diaza-1,3-butadienes with dialkyl phenylphosphonites under solvent-free conditions proceeds via zwitterionic intermediate and gives, by precipitation, the stable ylidic a-phosphanylidenehydrazones that, in turn, can be transformed into the corresponding 3-phenyl-2H-1,2,3lambda5-diazaphospholes. The latter compounds are converted by hydrolytic cleavage in methanol–water (95:5) into E-hydrazonophosphonates that are useful for the preparation of the corresponding b-ketophosphonates and 4-[alkoxy(phenyl)phosphoryl]-1,2-diaza-1,3-butadienes. These peculiar 1,2-diaza-1,3-butadienes, bearing an alkoxy(phenyl)phosphoryl group on the carbon atom in position 4 are also able to add different nucleophiles, such as methanol or thiourea, giving 2-[alkoxy(phenyl)phosphoryl]-2-methoxyhydrazones and 5-phosphinate-substituted thiazol-4-ones, respectively.
O. A. Attanasi, G. Baccolini, C. Boga, L. De Crescentini, P. Filippone, F. Mantellini (2008). Carbon–phosphorus bond formation and transformation in the reaction of 1,2-diaza-1,3-butadienes with alkyl phenylphosphonites. TETRAHEDRON, 64, 6724-6732 [10.1016/j.tet.2008.05.007].
Carbon–phosphorus bond formation and transformation in the reaction of 1,2-diaza-1,3-butadienes with alkyl phenylphosphonites
BACCOLINI, GRAZIANO;BOGA, CARLA;
2008
Abstract
The reaction of 1,2-diaza-1,3-butadienes with dialkyl phenylphosphonites under solvent-free conditions proceeds via zwitterionic intermediate and gives, by precipitation, the stable ylidic a-phosphanylidenehydrazones that, in turn, can be transformed into the corresponding 3-phenyl-2H-1,2,3lambda5-diazaphospholes. The latter compounds are converted by hydrolytic cleavage in methanol–water (95:5) into E-hydrazonophosphonates that are useful for the preparation of the corresponding b-ketophosphonates and 4-[alkoxy(phenyl)phosphoryl]-1,2-diaza-1,3-butadienes. These peculiar 1,2-diaza-1,3-butadienes, bearing an alkoxy(phenyl)phosphoryl group on the carbon atom in position 4 are also able to add different nucleophiles, such as methanol or thiourea, giving 2-[alkoxy(phenyl)phosphoryl]-2-methoxyhydrazones and 5-phosphinate-substituted thiazol-4-ones, respectively.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.