4-Amino-TEMPO as N-Nucleophile in Palladium-Catalyzed Aminocarbonylation

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• 作者：Má ; té ; Gergely ; Attila Taká ; cs and Lá ; szl&oacute ; Kollá ; r
• 刊名：Journal of Heterocyclic Chemistry
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：54
• 期：1
• 页码：634-640
• 全文大小：508K
• ISSN：1943-5193

文摘

Palladium-catalyzed aminocarbonylation of iodobenzene and iodoalkenes (1-iodocyclohexene, 4-tert-butyl-1-iodocyclohexene, α-iodostyrene, 17-iodoandrost-16-ene) was carried out using a free radical (4-amino-TEMPO) for the first time. Its reduced form (4-amino-2,2,6,6-tetramethylpiperidine) was also used as N-nucleophile. The free radical was partially reduced under aminocarbonylation conditions; however, the isolation of carbonylated products bearing a stable radical moiety was successfully accomplished. It was proved that the reduction of the 1-oxyl functionality took place to higher extent when more severe conditions (40 bar CO pressure) were used. The mixture of carboxamide and 2-ketocarboxamide products was obtained using iodobenzene because of single and double carbon monoxide insertion, respectively. In turn, carboxamide derivatives were formed exclusively when iodoalkenes were used as substrates.