C-H bond activation and C-C bond formation at adjacent metals.

摘要

Reaction of the methylene hydride compound [Ir2(H)(CO) 3(mu-CH2)-(dppm)2][CF3SO3] (1) with Me3NO removes a carbonyl, generating the fluxional methyl complex [Ir2(CH3)(CO)(mu-CO)(dppm) 2][CF3SO3] (2), the reactivity of which forms the basis of much of this thesis. Reaction of 2 with small molecules (CO, SO2, PR3, tBuNC) yields methylene hydride products by C-H activation of the methyl ligand.;Addition of activated alkynes or olefins to 2, yields cis dimetallated products. Compound 2 reacts at low temperature with non-activated 1-alkynes to initially yield the a etylide hydride complexes [Ir2(CH3)(H)(CO)2(mu-C≡CR)(dppm) 2][CF3SO3] (R = Me (14), Ph ( 17), H (20)). Upon warming, 14 and 17 transform into bridging alkyne complexes before eliminating methane at room temperature to yield bridging acetylide species. Compound 20 transforms into a vinylidene/methyl complex which upon reaction with CO generates a methylvinylidene/hydride.;Reaction of 2 with internal, non-activated alkynes, allene and methylallene initially yields the kinetic products in which the organic group bridges the metals cis to the methyl ligand. The allene adducts form rare mu-eta1:eta3-allene compounds. These products transform into the vinylcarbene compounds of formula [Ir2(H)(CO) 2(mu-eta1:eta3-CHCR=CR' H)(dppm)2][CF3SO3]. Isotopic labelling shows one route for the production of the vinylcarbenes from the bridging alkyne precursors and two routes for the generation from the allene and methylallene adducts.;The substituted methyl complex [Ir2(CH2OCH 3)(I)(CO)(mu-CO)(dppm)2] (40), was prepared by oxidative addition of iodomethyl methyl ether to [Ir2(CO) 3(dppm)2]. Compound 40 reacts with trimethylsilyl triflate and trimethylsilyl iodide to yield methylene bridged species. Reaction of 40 with methyl triflate generates a methoxycarbyne by removal of iodide ion and double C-H activation of the methoxymethyl ligand. (Abstract shortened by UMI.)