NHC‐Stabilized Dialanes(4) of Al2Mes4

Abstract

AbstractThe synthesis and characterization of novel N‐heterocyclic carbene (NHC) stabilized dialanes Al2Mes4 as well as first investigations concerning the reactivity of these compounds are reported. The synthesis of these compounds proceeds via the mesityl‐substituted alanes (NHC)⋅AlHMes2 (NHC=IMeMe{=1,3,4,5‐tetramethyl‐imidazolin‐2‐ylidene}, IiPrMe {=1,3‐di‐iso‐propyl‐4,5‐dimethylimidazolin‐2‐ylidene}) and iodo‐alanes (NHC)⋅AlIMes2 (NHC=IMeMe, IiPrMe). Metallic reduction of (NHC)⋅AlIMes2 afforded the new NHC‐stabilized dialanes (NHC)2⋅Al2Mes4 (NHC=IMeMe, IiPrMe). The NHC‐ligated dialanes are thermally robust and storable synthons for the dialane Al2Mes4. First reactivity studies on (IMeMe)2⋅Al2Mes4 towards small molecules confirm this, as this compound shows controlled and selective reactions with several substrates. Reaction with CuCl leads to oxidation of the dialane and formation of (IMeMe)⋅AlClMes2, reactions with pyridine N‐oxide and tBu−N=C=S, respectively, gave the chalcogenide‐bridged dimers {(IMeMe)⋅AlMes2}2‐μ‐E (E=O, S), and reaction with acetylene afforded the dimetallaacetylide {(IMeMe)⋅AlMes2}2‐μ‐(C≡C).