- Dinuclear μ-alkylidene complexes of transition metals as models for the transformation of CH2X2 (X=Cl, Br, I) into malonic acid derivatives by double carbonylation reactions
-
The carbonylation of the μ-alkylidene complexes Fe2(CO)8CH2 (1) and Pd2I2(PPh2CH2PPh2)2CH2 (2) has been studied under a variety of conditions.In the presence of an alcohol ROH, complex 1 gives mainly the acetate CH3CO2R, the product of monocarbonylation, whereas under the same conditions complex 2 gives the malonate CH2(CO2R)2, the product of dicarbonylation.The mechanisms of both reactions are discussed.From the fraction involving 1 a mononuclear complex resulting from the dimerization of ketene has been isolated, and its structure established by an X-ray diffraction study.Olefins such as ethene and norbornene are able to trap the ketene intermediate.The possible participation of such μ-alkylidene complexes in the direct transformation of CH2X2 (X=Cl, Br, I) into malonic acid derivatives is discussed.
- Denise, B.,Navarre, D.,Rudler, H.,Daran, J. C.
-
p. 273 - 289
(2007/10/02)
-
- Selective formation of malonate by a double CO insertion reaction into a μ-alkylidene complex of palladium
-
Whereas μ-alkylidene complex Fe2 reacts with CO and ROH to give mainly the ester CH3CO2R, the μ-alkylidene complex Pd2I2 gives malonate CH2(CO2R)2 with a selectivity of 88percent.
- Denise, B.,Navarre, D.,Rudler, H.
-
p. C83 - C85
(2007/10/02)
-
- CARBONYLATION DES COMPLEXES μ-ALKYLIDENIQUES: MISE EN EVIDENCE D'UN COMPOSE MINEUR PROVENANT D'UNE DOUBLE INSERTION DE CO
-
While the μ-alkylidenetungsten complex, (CO)9W2CHCH=C(CH3)2 gives the expected ester resulting from CO insertion-solvolysis reactions, the μ-alkylideneiron complex (CO)8Fe2CH2 gives, as well as the expected ester, a malonate formed by double carbonylation of the bridging carbon atom.
- Navarre, D.,Rose-Munch, F.,Rudler, H.
-
p. C15 - C18
(2007/10/02)
-