10.1002/adsc.200606108
The research focuses on the synthesis of β- and γ-lactams through intramolecular carbenoid C-H insertion of α-diazoacetamides using diruthenium(I,I) catalysts. The study investigates the efficiency of various dinuclear Ru(I,I) complexes with different bidentate bridging ligands in catalyzing the cyclization reactions. The reactants include a series of α-diazoacetamides with different N-substituents, such as diethyl, dibutyl, diisopropyl, dibenzyl, and benzyl-isopropyl variants. The catalysts used are of the type [Ru2(μ-L1)2(CO)4L2]2, where L1 can be a bridging acetate, calix[4]arenedicarboxylate, saccharinate, pyridin-2-olate, or triazenide ligand, as well as [RuCl2(pcymene)]2. The experiments involved the preparation of diazoacetamides and their subsequent decomposition using the catalysts. The products were analyzed using techniques such as 1H NMR, 13C NMR, IR spectroscopy, mass spectrometry, and elemental analysis to confirm their structures and determine the yields of the reactions. The study also compared the performance of the ruthenium catalysts with that of Rh2(OAc)4, a commonly used catalyst for such transformations, and observed differences in regioselectivity and chemoselectivity.
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