Palladium-Catalyzed Enantioselective α-Arylation of α-Fluoroketones

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• 作者：Zhiwei Jiao ; Jason J. Beiger ; Yushu Jin ; Shaozhong Ge ; Jianrong Steve Zhou ; John F. Hartwig
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：December 14, 2016
• 年：2016
• 卷：138
• 期：49
• 页码：15980-15986
• 全文大小：648K
• ISSN：1520-5126

文摘

The transition-metal-catalyzed α-arylation of carbonyl compounds is a widely practiced method for C–C bond formation. Several enantioselective versions of this process have been reported, but intermolecular, enantioselective coupling reactions of aryl electrophiles with α-fluoro carbonyl compounds have yet to be disclosed. We report enantioselective coupling of aryl and heteroaryl bromides and triflates with α-fluoroindanones catalyzed by palladium complexes of a BINOL-derived monophosphine and Segphos, respectively. The enolates were generated directly from α-fluoroindanones in the presence of potassium phosphate base during the reactions. We also report that reactions of α-fluorotetralones occur in high yields and enantioselectivities when conducted with enolates generated by elimination of trifluoroacetate from trifluoromethyl β-diketone hydrates. These reactions were catalyzed by palladium complexes of the commercially available bisphosphine Difluorphos. Thus, the formation of enantioenriched α-aryl-α-fluoroketones can be readily achieved by C–C bond formation when the appropriate palladium catalyst and α-fluoro enolate precursor were used.