Coupling reactions, metal catalysed carbonylative

Transition metal-catalysed carbon-heteroatom coupling reactions primarily comprise the carbonylation polycondensation of dibromoarenes with aromatic diamines and bisphenols in the presence of carbon monoxide... 

Iron-catalysed cross-coupling and olefin hydrofunctionalisation reactions have emerged that operate well in the absence of the more commonly required noble metals. Similarly, operationally simple and practical iron-catalysed carbonyl and olefin hydrogenation procedures are now available, providing inexpensive routes for molecule construction. 

There has been a review of palladium-catalysed carbonylative coupling reactions of aryl halides with carbon nucleophiles in the presence of carbon monoxide. It has been shown that rhodium is an efficient catalyst for the homocoupling reaction of arylzinc compounds in the presence of 1 atm of carbon monoxide to give diaryl ketones. Under similar conditions, palladium and nickel catalysts yield biaryls. The beneficial catalysis by rhodium is likely to derive from the ease of migration of the aryl ligand to carbon monoxide in the rhodium(III) intermediate. A rhodium catalyst has also been used in the formation of indole-3-carboxylates by reaction of indoles with alcohols in the presence of carbon monoxide. The catalytic cycle. Scheme 5, is likely to involve metallation of the indole at the 3-position, followed... 

It should be noted that the coupling reaction of nitrobenzene to afford azobenzene had been earlier reported to proceed even in the absence of any catalyst, but only under 3000 atm of CO [107]. However, it should also be noted that metallic iron is known to partly react with CO under pressure and the formation of Fe(CO)s by reaction of CO with the stainless steel walls of an high-pressure IR cell has been observed even under only 1 atm of CO [108]. Thus, even in this older experiment, some Fe(CO)s was surely present, which catalysed the reaction. The high pressure is probably required in order to produce significant amounts of the iron carbonyl. Indeed, by replacing Fe(CO)s with finely divided iron powder under the milder conditions of eq. 16, no reaction was observed. 

A text and the proceedings of a conference describe catalytic applications of transition-metal compounds in organic synthesis. New developments in nickel-catalysed carbon-carbon bond formation and the coupling of alkyl groups using transition-metal catalysts have also been reviewed. [TiGp2Cl2] catalyses reaction (23) (n = 1 or 2, X = Mg) carbonylation of the product followed by hydrolysis gives y- or 5-lactones (i.e. X = CO). ... 

---