β-Lactam and penicillin substituted mesoionic metal carbene complexes

1,2,3-Triazolylidene MIC M-complexes (M = Au, Pd, Pt) having 2-azetidinones and penicillin G substituents at the triazole ring were prepared by CuAAC on 2-azetidinones having a terminal alkyne tethered at N1, followed by alkylation of the 1,2,3-triazole ring and transmetallation [Au(i), Pd(ii) and Pt(ii)]. The Au–MIC complexes efficiently catalyze the regioselective cycloisomerization of enynes, while the Pt–MIC complexes were efficient catalysts in hydrosilylation reactions.