Dehydrogenative Dual Ammonia Activation and Transfer by an N‐Heterocyclic Boryloxy Aluminyl Compound
Debotra Sarkar, Petra Vasko, Lu Ying, Job J. C. Struijs, Liam P. Griffin, Simon Aldridge
Abstract
Abstract The reactivity of an N‐heterocyclic boryloxy (NHBO) ligated aluminyl compound has been harnessed for main‐group‐mediated dehydrogenative dual activation of ammonia. The Al(I) system K[{(HCDippN) 2 BO} 2 Al] reacts with excess NH 3 to give the Al(III) bis(amide) K[{(HCDippN) 2 BO} 2 Al(NH 2 ) 2 ] and in the process generates H 2 . The initial stage of the reaction proceeds via formal N−H oxidative addition at Al(I) (via a coordination/proton shuttling sequence) to give an aluminium(III) primary amido hydride. Subsequent protonolysis of the strongly hydridic Al−H bond selectively yields the corresponding aluminium bis(amide) and H 2 . This step occurs without competing protolytic ligand loss – exploiting the limited basicity of the supporting [(boryl)O] − donors. In terms of amide transfer reactivity, the utility of K[{(HCDippN) 2 BO} 2 Al(NH 2 ) 2 ] in delivering one or both equivalents of [NH 2 ] − to electrophilic substrates (HBpin, CO 2 and Ph 2 CO) has been demonstrated.