84718-90-1Relevant academic research and scientific papers
PHOTOLYSIS OF SOME UNSYMMETRICAL PHOSPHINIC AZIDES IN METHANOL. RELATIVE MIGRATORY APTITUDES OF ALKYL GROUPS AND PHENYL IN THE CURTIUS-LIKE REARRANGEMENT.
Harger, Martin J. P.,Westlake, Sally
, p. 3073 - 3078 (2007/10/02)
When an alkylphenylphosphinic azide RPhP(O)N3 (R=Me, Et, Pri or But) is photolysed in MeOH either the alkyl or phenyl group can migrate from P to N in the Curtius-like rearrangement.The composition of the product shows that migration of the alkyl group R is preferred.However, the preference is not great and decreases as R changes But->Pri->Et->Me-> (approx. migratory aptitudes relative to Ph: 2.1, 1.7, 1.3, 1.2 respectively), probably because the Ph-P bond is better able to assume the correct conformation for Ph migration when R is less bulky.For t-butylmethylphosphinic azide there is very little preference for migration of But relative to Me.Small amounts of unrearranged products such as ButPhP(O)NHOMe and ButPhP(O)NH2 are generally produced in the photolyses, together with the methyl phosphinates RPhP(O)OMe (major product when R=Me) resulting from (non-photochemical) solvolysis of the azide.
