Synthesis and Structure of Lewis Base‐Coordinated Phosphanylalumanes Bearing P–H and Al–Br Moieties

Abstract

Phosphanylalumanes bearing hydrogen and halogen substituents (RHP–AlXR, R = organic substituent, X = halogen) are expected to be useful synthetic precursors for P=Al doubly bonded species, phosphaalumenes (RP=AlR), though there have been only limited number of H,X‐functionalized phosphanylalumanes. In this communication, synthesis and structure of a Lewis base coordinated phosphanylalumane bearing P–H and Al–Br moieties are reported. Reaction of LiPHMes with BbpAlBr₂(OEt₂) {Bbp = 2,6‐[CH(SiMe₃)₂]₂C₆H₃} followed by the treatment with a N‐heterocyclic carbene (L) afforded the Lewis base coordinated H,Br‐functionalized phosphanylalumane, MesP(H)‐Al(Br)(L)Bbp (L = N‐heterocyclic carbene). Its Al–P bond length is comparable to that observed for the previously reported H,Cl‐functionalized phosphanylalumane free from Lewis base‐coordination, indicating the negligible contribution of Al=P double‐bond character in the phosphanylalumane derivatives.

Abstract

A Lewis base coordinated phosphanylalumane bearing P–H and Al–Br moieties was synthesized. Its Al–P bond length is comparable to those of phosphanylalumanes free from Lewis base‐coordination, indicating negligible contribution of Al=P double‐bond character in phosphanylalumanes. Deprotonation of the P‐bound hydrogen of the newly synthesized H,Br‐functionalized phosphanylalumane was investigated.