e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
Tetrahedron
Photolysis of some unsymmetrical phosphinic azides in methanol: Relative migratory aptitudes of alkyl groups and phenyl in the curtius-like rearrangement
MJP Harger, S Westlake
Index: Harger, Martin J. P.; Westlake, Sally Tetrahedron, 1982 , vol. 38, # 20 p. 3073 - 3078
When an alkylphenylphosphinic acid PRhP (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 and 1.2 respectively), ...