Migration aryloxide

The different products which are obtained due to hydroxybenzyl migration can be trapped by metal complexation. The thus formed trivalent, N403-encapsulating ligand adopts a pentagonal bipyramidal geometry at the ytterbium center with two aryloxide oxygens in the axial positions. 

A detailed study of the specific rates of solvolysis of N,N,N, N -tetra-methyldiamidophosphorochloridate (80) (TMDAPC) with analysis in terms of the extended Grunwald-Winstein equation has been reported (Scheme 19). The stereochemistry of nucleophilic attack at tetracoordinate phosphorus was also discussed." The initial reaction of bis (2,4-dinitrophenyl) phosphate (BDNPP) (81) with hydroxylamine involves release of 1 mol 2,4-dinitrophen-oxide ion and formation of a phosphorylated hydroxylamine (82), which reacts readily with further NH2OH, giving the monoester (83). The intermediate (82) also breaks down by two other independent reactions one involves intramolecular displacement of aryloxide ion (83) and the other involves migration of the 2,4-dinitrophenyl group from O to N and formation of phosphorylated 2,4-dinitrophenylhydroxylamine (84) (Scheme 20)." ... 

The reactions of A-chloroalkylphosphazenes with hydroxylamine hydrochloride to give (73) proceed in a similar manner. Derivatives of (73) were obtained by reactions with arylamines, with sodium aryloxides, and with acetic (or formic) acid. The latter is noteworthy in that the proton of the hydroxy-group in (74) does not migrate to nitrogen. 

The tungsten alkylidynes Tp W( = CH)(CO)2 and Tp W(=CPh)(CO)2 also arise from side reactions of phosphonium alkylidyne complexes with aryloxide nucleophiles from reaction of the quaternary phosphonium salts with adventitious hydroxide to give a dissociated alkyl anion or a product resulting from a 1,2-phenyl migration. At low temperature, phenyl migration is inhibited and only the terminal dissociation product is observed. At room temperature, both phenyl and C-H alkylidyne products form in an approximate 1 1 ratio. 

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