Diruthenium(I,I) Catalysts for the Formation of β‐ and γ‐Lactams via Carbenoid CH Insertion of α‐Diazoacetamides

Abstract

Intramolecular carbenoid C À H insertion of five a-diazoacetamides [N 2 CH À CONR 2 , NR 2 = NEt 2 (3a), NBu 2 (3b),

Oxidative-addition of the N–H bond of saccharin (sacH) to a triosmium centre: Synthesis, structure and reactivity of Os3(CO)10(μ-H)(μ-sac)

“…The organometallic chemistry of the sac has been relatively neglected and only a few organometallic sac complexes are known [4][5][6][7][8]. In 1987, Beck and co-workers reported sac complexes of the Group VI metal carbonyls Na[M(CO)5(κ 1 -(N)-sac)] from the reactions of M(CO) 5(thf) and Na(sac) [8].…”

“…Both of these complexes undergo axial carbonyl substitution in the presence of 2-electron donor ligands to give substituted diruthenium complexes [4]. Further, A and B are suitable pre-catalysts for the cyclopropanation of nucleophilic alkenes with methyl diazoacetate [4], the later has also been found to catalyze the intramolecular carbenoid C-H insertion of α-diazo esters leading to the formation of β-and/or γ-lactams [5,6].…”

Activation of thiosaccharin at a polynuclear osmium cluster

“…In 2006, Buck and Maas reported the isolation of the di-and tetra-ruthenium complexes, [Ru2(CO)6(μ-sac)2] and [Ru4(CO)12(μ-sac)4], respectively, from the reactions of Ru3(CO)12 with excess sacH at elevated temperatures [18]. Moreover, these authors found that both sac-containing compounds function as suitable pre-catalysts for the cyclopropanation of nucleophilic alkenes with methyl diazoacetate [18], with the Ru4 system also able to catalyze the intramolecular carbenoid C-H insertion in 2-diazoacetoacetamides to yield βand/or γ-lactams [20,21]. Recently, we reported the first triosmium clusters containing an ancillary sac ligand from the reactions of [Os3(CO)10-n(NCMe)n] (n = 1, 2) with sacH in refluxing benzene.…”

Sawhorse-type diruthenium tetracarbonyl complexes

“…2 ] n have been found to catalyze in dichloromethane the intramolecular degradation of ␣-diazo acetamides to give lactams [Eqs. (38) and (39)], depending on the substituents in the amido function [117].…”