The sequential one-pot double dearomatization of bis(
N-benzyl-
P,
P-diphenylphosphinamides) via anioniccyclization is described for the first time. Protonation and alkylation of the dearomatized dianions providebis(tetrahydro-2,1-benzazaphospholes) in good yield and with very high regio- and stereocontrol. Acid-catalyzed methanolysis of the bisheterocycles affords bis(methyl
-aminophosphinates) stereospecifically.The doubly phosphorylated systems proved to be active against a series of cancer cell lines.