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

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 BbpAlBr 2 (OEt 2 ) {Bbp = 2,6‐[CH(SiMe 3 ) 2 ] 2 C 6 H 3 } 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.