Halides chromium carbonyl complex

Dinuclear carbonyl complexes, with copper, 2, 187-188 Dinuclear chromium(III) complexes, with halides, alkyls, aryls, 5, 317... 

Aryl halides may be carbonylated using several different palladium complexes and several different hydrogen donors839,840,842,843. In most synthetically useful reactions the conditions are reasonably low pressure (up to 6 bar) and reasonably low temperatures (below 100 °C). Halobenzenes have also been successfully carbonylated at 30 bar using a carbon monoxide/hydrogen mixture in the presence of a palladium catalyst and triethy-lamine. In this case the halobenzene must first be complexed with chromium tricarbonyl844. 

Vanhoye and coworkers [402] synthesized aldehydes by using the electrogenerated radical anion of iron pentacarbonyl to reduce iodoethane and benzyl bromide in the presence of carbon monoxide. Esters can be prepared catalytically from alkyl halides and alcohols in the presence of iron pentacarbonyl [403]. Yoshida and coworkers reduced mixtures of organic halides and iron pentacarbonyl and then introduced an electrophile to obtain carbonyl compounds [404] and converted alkyl halides into aldehydes by using iron pentacarbonyl as a catalyst [405,406]. Finally, a review by Torii [407] provides references to additional papers that deal with catalytic processes involving complexes of nickel, cobalt, iron, palladium, rhodium, platinum, chromium, molybdenum, tungsten, manganese, rhenium, tin, lead, zinc, mercury, and titanium. 

Metal carbonyl halides can also undergo photoredox reactions if an MLCT chromophoreofsuitableenergyispresentinthecomplex.ThecomplexCrI(CO)5, for example, has a characteristic long-wavelength absorption at 638 nm that is due to an I - Cr (LMCT) absorption. Irradiation into this chromophore for a solution of CrI(CO)5 in acetonitrile leads to the formation of iodine and the zerovalent chromium complex Cr(CO)5MeCN with a quantum yield of 0.01 (Ref. 65) ... 

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