Pd/Light‐Accelerated Atom‐Transfer Carbonylation of Alkyl Iodides: Applications in Multicomponent Coupling Processes Leading to Functionalized Carboxylic Acid Derivatives |
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Authors: | Dr Akira Fusano Shuhei Sumino Satoshi Nishitani Takaya Inouye Keisuke Morimoto Dr Takahide Fukuyama Prof Ilhyong Ryu |
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Institution: | Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599‐8531 (Japan), Fax: (+81)?72‐254‐9695 |
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Abstract: | The atom‐transfer carbonylation reaction of various alkyl iodides thereby leading to carboxylic acid esters was effectively accelerated by the addition of transition‐metal catalysts under photoirradiation conditions. By using a combined Pd/hν reaction system, vicinal C‐functionalization of alkenes was attained in which α‐substituted iodoalkanes, alkenes, carbon monoxide, and alcohols were coupled to give functionalized esters. When alkenyl alcohols were used as acceptor alkenes, three‐component coupling reactions, which were accompanied by intramolecular esterification, proceeded to give lactones. Pd‐dimer complex Pd2(CNMe)6]PF6]2, which is known to undergo homolysis under photoirradiation conditions, worked quite well as a catalyst in these three‐ or four‐component coupling reactions. In this metal/radical hybrid system, both Pd radicals and acyl radicals are key players and a stereochemical study confirmed the carbonylation step proceeded through a radical carbonylation mechanism. |
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Keywords: | carbon monoxide carbonylation multicomponent reactions palladium radical reactions |
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