Synthesis and structures of new symmetrically and unsymmetrically substituted cyclodiphosphazanes

Abstract

The reaction of λ 3-diazadiphosphetidine [ClPN t-Bu] 2 ( 1a) with phenols in the presence of triethylamine or as their sodium salts affords only cis-[(ArO)PN t-Bu] 2 as isolable products; thus, several compounds where ArO=2,6-dimethylphenoxy ( 2), 2-naphthoxy, 4-methoxy ( 3), 4-methoxyphenoxy ( 4), 4-methylphenoxy ( 5), 4- t-butylphenoxy ( 6) and 1-anthryloxy ( 8) were synthesized. The reaction of 1a with 1 mol equivalent of 2,6-dimethyl phenol or 2-naphthol afforded the unsymmetrical derivatives [ClP(N- t-Bu) 2P(OAr)], where ArO=2,6-dimethyl phenoxy ( 9) or 2-naphthoxy ( 10), which could be characterized by 31P NMR spectroscopy. In a rather unusual reaction, 9 reacted with excess cyclohexylamine to give the unsymmetrical hydrolyzed product [H(O)P(N- t-Bu) 2(NHC 6H 11)] ( 11). A single crystal X-ray structure determination confirms the cis disposition of aryloxy groups in 2 as well as that of the phosphoryl oxygen and the cyclohexylamino group in 11.