IMINOPHOSPHANES AND AZADIPHOSPHIRIDINE IMINES

A variety of bis(alkyl)iminophosphanes R-P=N-R' 3a-e (R = CMe2Et, CMeEt2, CEt3; R' = CMe3, CEt3) and arylimine-substitued derivatives [R' = 2,4,6-tBu3C6H2, R = CEt3 (3f), R = PhCH=CH (3g)] are obtained by base-induced dehydrochlorination from the corresponding amino(chloro)phosphanes R-P(Cl)-N(H)R' 2a - g. Depending on the steric demand of the substituents, the iminophosphanes 3a - d undergo a reversible [2 + 1] cyclodimerization to give the azadiphosphiridineimines R-P(=NR')-P(R)-N-R' 4a - d. The same ring system is obtained in the reaction of 3c with the (arylimino)phosphanes R-P=N aryl (R = PhCH=CH, Et, Me). However, this cycloaddition results in the formation of diastereomers 4e - g and 4'e - g, respectively. The reaction of Et-P=N-aryl with R-P=N-aryl (R = PhCH=CH, Cl) furnishes (phosphanylamino)iminophosphanes Et(R)P-N(aryl)-P=Naryl 5a,b. The compounds 3f, 4e, f, and 5a have been characterized by X-ray structure analyses.