Reaction of the NHC-stabilized mono- and bis-iodo-alanes with NaCp afforded the corresponding Cp-substituted compounds that show dismutation in solution. Using magnesocene MgCp2 as Cp source led to isolation of tetranuclear Al2Mg2 compounds with interesting structural motifs including bridging hydrides between Al and Mg centers.
The mono- and bis-iodo-substituted NHC-stabilized alanes (NHC) ⋅ AlH2I and (NHC) ⋅ AlHI2 offer a convenient entry for further substitution reactions at aluminum. Reactions of (NHC) ⋅ AlH2I 1–4 with one equivalent of NaCp afforded the adducts (NHC) ⋅ AlH2Cp 9–12 (NHC=Me2ImMe (9), iPr2ImMe (10), iPr2Im (11), Dipp2Im (12)). Alane adducts with two Cp substituents (NHC) ⋅ AlHCp2
13–16 (NHC=Me2ImMe (13), iPr2ImMe (14), iPr2Im (15), Dipp2Im (16)) were prepared by the analogous reaction of (NHC) ⋅ AlHI2
5–8 using two equivalents of NaCp. The unusual dimeric adducts ((NHC) ⋅ AlH2Cp ⋅ CpMgI)2
17–19 (NHC=Me2ImMe (17), iPr2ImMe (18), iPr2Im (19)) were obtained from the reaction of 1–3 with MgCp2.Zum Volltext