Synthesis and structures of new symmetrically and unsymmetrically substituted cyclodiphosphazanes

Abstract

The reaction of λ3-diazadiphosphetidine [ClPNt-Bu]2 (1a) with phenols in the presence of triethylamine or as their sodium salts affords only cis-[(ArO)PNt-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(NHC6H11)] (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. © Elsevier Science Ltd.