摘要：

Reaction of the aminotriphenol, tris (2-hydroxy-3-methyl-5-tert-butylbenzyl)amine, with triphenylphosphite resulted in the formation of the first structurally characterized pentaoxyphosphorane-atrane, N[CH2(Me( t -Bu)C6H2)O]3P(OPh)2 ( 1 ) while reaction of the aminotriphenol, tris (2-hydroxy-3,5-dimethylbenzyl)amine ( E ) with 2,2ethylidenebis(4,6-di- tert -butylphenyl)fluorophosphite led to the isolation of the phosphorane, N[CH2(Me2C6H2)O]2P[OC6H2( t -Bu)2]2CHCH3 ( 2 ), as a result of aminotriphenol to aminodiphenol conversion. X-ray analysis revealed the octahedral geometry of 1 showing strong P-N dative bond coordination (2.114(6) ) and the trigonal bipyramidal arrangement for 2 exhibiting a normal P-N covalent bond (1.652(2) ). 1H, 13C and 31P NMR measurements assisted in the structural interpretations and in comparisons with related compounds. The results confirm the premise that donor action at the transition state of active sites of phosphoryl transfer enzymes should enjoy enhanced reaction with nearby donor groups that are positioned to enter into coordination with the reactive phosphoryl component, especially for such enzymatic reactions that exhibit catalytic promiscuity.

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