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The paramagnetic Co3(CO)9(μ3−S) cluster (1) reacts with organic compounds containing S−H, S−S, or P−H bonds to give diamagnetic Co3(CO)7(μ-X)(μ3−S) (μ-X = (μ-L, μ-(1,2-η)-L, and μ-(1,3-η)-L) complexes. The reaction was used to prepare the derivatives with μ-L = SR (2a−h; R = Et, t-Bu, CH2Ph, allyl, Ph, C6F5, 2-naphthyl, CH2CH2OH) and PPh2 (7), μ-(1,2-η)-L = P(S)Ph2 (8), and μ-(1,3-η)-L = S2CR (R = SMe (4), OMe (5), Ph (6)). The reaction results in an increase of the oxidation state of cobalt and may be therefore called an oxidative substitution. It is the first successful and rational way to prepare derivatives of Co3(CO)9(μ3-S), a fundamental cluster molecule described in 1961. The crystal structures of the triphenylphosphine-substituted derivative of 2b, Co3(CO)4(PPh3)3(μ-S-t-Bu)(μ3-S) (3), and of 4, 6, and 8 were determined. A new, high-yield synthesis of 1 is described.

Hydroxycarbonylation of benzyl and substituted benzyl chloride and bromide derivatives was achieved in good yields (up to 97.6%) and quantitative chemoselectivity, in the presence of Co2(CO)8 as the transition metal and polyethylene glycols as the phase-transfer catalyst in an organic solvent/20% aqueous NaOH two-phase system under mild conditions (1 bar CO, room temperature). η1-Benzyl-, η3-benzyl-, and (η1-phenylacetyl)cobalt carbonyls were investigated as intermediates of this catalytic process.

The «one-pot» combined hydrocarbalkoxylation-Michael addition reaction offers a relatively simple synthetic tool to prepare polyfunctionalized compounds from common starting materials. Furthermore, our results gave a new example for the control of homogeneous catalytic systems by basic additives

Phthalimidomethyl and phenoxymethyl as well as corresponding acetyl cobalt tetracarbonyls (1-4) were prepared and characterized. The single-crystal X-ray diffraction molecular structure of 1 (the first X-ray structure of an alkylcobalt tetracarbonyl with a pure organic alkyl group) was determined. The equilibrium constants of the equilibria 1 half arrow pointing right over half arrow pointing left 2 and 3 half arrow pointing right over half arrow pointing left 4 were determined at 20-60 and 20-40 degrees C, respectively

La reaction serait une addition 1,4 concertee determinant la vitesse de HCo(CO) 4 a la conformation cis de dimethylbutadiene avec formation de (dimethyl-2,3 butenyl-2)-Co(CO) 4

La reaction de HCo(CO) 4 avec l'acrylate d'ethyle catalysee par CO 2 (CO) 8 en presence de CO donne: propionate d'ethyle, formyl-2 propionate d'ethyle et ((ethoxycarbonyl)-1 ethyl)-Co(CO) 4 . Effet de la temperature

Mecanisme de la reaction donnant Et 3 SiCo(CO) 4 et H 2 . Des quantites catalytiques de pyridine ou tributylphosphine augmentent la vitesse et changent la cinetique de la reaction

Etudes de la catalyse par les amines tertiaires, les heterocycles azotes, les phosphines ditertiaires et les ions halogenures