Studies on cyclic α-aminoalkanephosphonate compounds: A novel synthesis of 2-phenyl-1,4,2-benzoxaza (or diaza)phosphorin 2-oxides

Numerous cyclic α-aminoalkanephosphonates, 2-phenyl-1,4,2-benzoxaza (or diaza) phosphorin 2-oxides 6a-o and 8 have been prepared by a Mannich-type reaction of o-aminophenol or o-phenylenediamine with phenyldichlorophosphine and aldehydes or ketones. The cis and trans-geometric isomers of the title compounds were stereoselectively generated, depending upon the aldehyde or ketone substrates used. The synthetic methods provide an easy access to the organophosphorus heterocycles with the ring system mentioned above.