Reducing hybrid ligand-based alane and chasing aluminium(): dialane and unusual transient dialumene

In this work, an alane, [DNIAlH 2 ] ( 1 ) (DNI = 3,3-dimethyl-2-[2-methyl-2-(2,6-diisopropyl-aniline)ethenyl]-3 H -indolenine), stabilised by a hybrid ligand was reduced by Jones's Mg( i ) ([( Mes BDIMg) 2 ]) and Roesky's Al( i ) ([ Dipp BDIAl:]). The resulting dialane compound [{DNI(H)Al} 2 ] ( 2 ) was characterised using NMR spectroscopy, mass spectrometry, DFT calculations and single-crystal XRD experiments. The reaction of aluminium dihydride [DNIAlH 2 ] ( 1 ) with [ Dipp BDIAl:] at high temperatures gives an intramolecular C(sp 2 )-H bond-activated compound 3 . To study the monomeric hybrid ligand-based Al( i ), characterisations and computational calculations were performed, which elucidate that compound 5 , consisting of two inequivalent aluminium atoms in an Al 2 CN four-membered ring, resulting from the activation of a carbon-nitrogen bond in the reaction of [DNINa] with [(Cp*Al) 4 ]. The alane [DNIAlH 2 ] ( 1 ) was reduced by Jones's Mg( i ) and Roesky's Al( i ) to give the dialane [{DNI(H)Al} 2 ] ( 2 ). 1 with [ Dipp BDIAl:] gives intramolecular C(sp 2 )-H bond-activated 3 . [DNINa] with [(Cp*Al) 4 ] gives C-N activated 5 with an Al 2 CN ring.