Catalysts for carbonylation

The addition of alcohols to form the 3-alkoxypropionates is readily carried out with strongly basic catalyst (25). If the alcohol groups are different, ester interchange gives a mixture of products. Anionic polymerization to oligomeric acrylate esters can be obtained with appropriate control of reaction conditions. The 3-aIkoxypropionates can be cleaved in the presence of acid catalysts to generate acrylates (26). Development of transition-metal catalysts for carbonylation of olefins provides routes to both 3-aIkoxypropionates and 3-acryl-oxypropionates (27,28). Hence these are potential intermediates to acrylates from ethylene and carbon monoxide. 

E.2. Supported Dendritic Catalysts for Carbonylation, Hydroesterification, Oxidation, and Heck Reactions... 

Use of Ni as a catalyst for carbonylation of methanol has been known for decades (11-14). The reaction was characterized by high temperature (200-300 C) and pressure (5000-10,000 psi). However, when BASF built methanol carbonylation plants in the early sixties, the catalyst of choice was cobalt, not nickel, in spite of its lower selectivity. Nickel was less reactive, more volatile as the carbonyl, and required higher temperature and pressure than cobalt. 

K., Matsukawa, S., Volk, T, and Terada, M. (1998) Self-assembly of several components into a highly enantioselective Ti catalyst for carbonyl-ene reactions. Angew. Chem., Int. Ed., 36, 2768-2771. 

MONO AND TRIDIRECTIONAL 12-MEMBERED RING ZEOLITES AS ACID CATALYSTS FOR CARBONYL GROUP REACTIONS... 

Lewis acid]+[Co(CO)4] complexes have been reported as a versatile class of catalysts for carbonylative ring expansion of aziridines to p-lactams [147]. For instance, catalysts such as [C5H5Ti(thf)2][Co(CO)4] and [(salph)Al(thf)2][Co (CO)4]1 [148] have been shown to efficiently carbonylate a variety of aziridines under mild conditions. Further, the authors proposed a mechanism for the CO insertion into aziridines. A theoretical investigation has been also reported for the [Co(CO)4] -catalyzed carbonylative ring expansion of (V-benzoyl-2-methylaziri-dine to p-lactams (Scheme 58), [149]. 

Carbonylation of CH2=CHX and halodienes.1 Ni(CN)2 is an active catalyst for carbonylation of unsaturated halides under phase-transfer conditions. The effective species is probably a cyanotricarbonylnickelate. Thus in the presence of cetyltri-... 

Ruthenium complexes are also suitable catalysts for carbonylation reactions of a variety of substrates. Indeed, when a reaction leads to C-Ru or het-eroatom-Ru bond formation in the presence of carbon monoxide, CO insertion can take place at the coordinatively unsaturated ruthenium center, leading to linear ketones or lactones. Thus, ruthenium-catalyzed carbonylative cyclization was involved in the synthesis of cyclopentenones by reaction of allylic carbonates with alkenes in the presence of carbon monoxide [124] (Eq. 93). 

SAFETY PROFILE Mutation data reported. Human systemic effects by intradermal route dermatitis. When heated to decomposition it emits toxic fumes of K2O and Cl". Used as a catalyst for carbonylation of alkynes. See also PLATINUM COMPOUNDS. 

Some other olefins are carbonylated similarly carbon monoxide is introduced at the terminal position to form )3-chloroacyl halides (10). In addition, it was found that metallic palladium is a versatile catalyst for carbonylating various olefins. Saturated esters are prepared by carbonylating simple a-olefins and some cyclic olefins when the reaction is carried out in alcohol containing hydrogen halide and a catalytic amount... 

As far as the central atoms are concerned, in particular the Group VIII metals Co, Ni, Ru, Rh, Pd, Ir, and Pt form effective carbonylation catalysts, each metal demonstrating a different carbonylation activity. Rh and Ir are the most active and preferred catalysts for carbonylation reactions to produce acetic acid or acetic anhydride, or for co-production of acetic acid and acetic anhydride [1, 2]. Co is only of historical interest. 

The synthesis of carboxylic acids by carbonylation of unsaturated hydrocarbons or alcohols was developed mainly by Reppe and his co-workers in the laboratories of BASF at Ludwigshafen. Many industrially important processes such as the synthesis of acrylic acid, propionic acid, and acetic acid were elaborated there in the period from the late 1930s to the mid-1950s [1, 2]. Reppe s introduction of metal carbonyls as catalysts for carbonylation reactions was of paramount importance and many processes, which are still industrially relevant today, were developed rapidly (eq. (1), [3]). 

Evans, D. A. Stereoselective organic reactions catalysts for carbonyl addition processes. Science 1988, 240,420-426. 

The polymer-immobilised nanogold is also an effective catalyst for carbonylation of amines with CO2 to yield corresponding disubstituted ureas... 

Palladium complexes of TPPTS and TPPMS have been employed extensively as catalysts for carbonylation, hydroxycarbonylation, and C—C cross-coupling reactions (cf. Section 6.6). Hydroxycarbonylation of bromobenzene in biphasic medium using Pd(TPPTS)3 as catalyst yields benzoic acid, which remains in the aqueous phase, thus avoiding the direct recycling of the catalyst [59]. The formation of Pd(TPPTS)3 from PdCl2 and TPPTS in aqueous solution has been studied in detail by 170, 1H 31P, and 35C1 NMR spectroscopy. The complex [ PdCI(TPPTS)3 Cl obtained initially is reduced by excess TPPTS, TPPTSO being formed. A more attractive synthesis of Pd(TPPTS)3 involves the facile reduction of [PdCl-(TPPTS)3]+C1- with CO (Scheme 1) [60],... 

The hydroxycarbonylations (carboxylations) of alkyl, aryl, benzyl and allyl halides are from a retrosynthetic and mechanistic standpoint closely related. This type of reaction is widely used in organic synthesis [6], although a stoichiometric amount of salt by-product makes these methods less attractive on a large scale. The use of water-soluble catalysts for carbonylation of organic halides was scarcely studied in the past. Up to now palladium, cobalt, and nickel compounds in combination with water-soluble ligands have been used as catalysts for various carboxylations. 

Rh catalyst for carbonylation, decarbonylation, oxygenation, benzyl cleavage (see 1st edition). 

Metal cations and other Lewis acids can replace protons as reagents/catalysts for carbonyl addition reactions. Metal cations, for example, are involved in hydride and organometallic addition reactions. Metal cations and Lewis acids are also key reagents in the aldol-type reactions that are considered in Section 7.7. 

Fukawa, H., Izumi, Y., Komatsu, S., and Akabori, S. (1962) Studies on modified hydrogenation catalyst. 1. Selective hydrogenation activity of modified Raney nickel catalyst for carbonyl group and C=C double bond. Bull. Chem. Soc. Jpn., 35, 1703-1706. 

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