Cobalt/rhodium catalysts amidocarbonylations

Amidocarbonylation is a recently developed, organometallic-catalyzed route to amino acid generation - particularly A(-acyl a-amino acids - using either aldehydes or alkenes as starting materials and synthesis gas as an integral building block. The two principal classes of reaction are illustrated in eqs. (1) and (2). Both syntheses offer the opportunity to introduce two functionalities, amido and carboxylate, simultaneously where an amide is the co-reactant. Homogeneous amidocarbonylation catalysts are typically cobalt carbonyl-based, or utilize transition-metal binary systems, e. g. cobalt-rhodium, cobalt-palladium, and cobalt-iron. 

A regioselective hydroformylation-amidocarbonylation process of a fluoroolefin is reported for cobalt-rhodium bimetallic catalyst systems With Rh6(CO),6 and Co2(CO)8 (1 50) in dioxane, 3,3,3-trifluoropropene (57) reacts with acetamide under hydroformylation conditions to give 58 with 94% selectivity (80-bar CO, 50-bar H2, 120°C, 10 hr, CT821) (226,275) ... 

Cobaltcarbonyls are used as catalysts for carbonylations such as hydroformylation (0x0 reaction), hydrocarbonylation and amidocarbonylation [70a]. Hydroformylation is the reaction of preparing aliphatic aldehydes in which carbon number is increased by one [46]. Especially, butylaldehyde has been industrially produced largely from propylene butylaldehyde is used as a raw material for butanol and 2-ethylhexanol, etc. Cobalt and rhodium compounds are used for their catalysts. The reactivity of cobalt catalysts is lower than that of rhodium catalysts. However, more linear products of the reaction shown in eq. (17.27) are obtained. The ratio of... 

New Steroidal derivatives of androstene and pregnene containing an a-amino moiety have been prepared in a one-pot hydroformylation-amidocarbonylation reaction using a rhodium or a rhodium-cobalt complex catalyst [157]. 

A number of publications have appeared revealing that catalytic processes which are unsuccessful with vinylic fluondes can be applied effectively to fluoro-alkyl- and fluoioarylethylenes Hydroformylation [56] and related reactions such as amidocarbonylation [571 will proceed in high yield and regioselectivity The choice of the catalyst system, especially of rhodium and cobalt catalysts, allows either regioselective reaction to proceed A few of the large number of syntheuc variants are given in equation 45... 

A broad range of olefins, acetals, epoxides, alcohols, and chlorides were demonstrated effective alternative starting materials. Cobalt and rhodium carbonyls and bimetallic complexes catalyzed the domino hydroformylation-amidocarbonylation of olefins (17-22). Addition of 0.1 mol% RheCCOie to the cobalt catalyst gave branched AT-acetyltrifluorovaline, which indicated that the hydroformylation step governs the regioselectivity of the domino process (Scheme 4) (22). 

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