Palladium(II)-Catalyzed Direct Arylation of Enaminones Using Organotrifluoroborates
摘要:
A Pd(II)-catalyzed reaction for the direct aryation of cyclic enaminones is reported. The reactivity of electron-rich, electron-poor, and sterically encumbered organotrifluoroborates was investigated. This reaction represents a unique use for organotrifluoroborates as coupling partners and discloses the utility of enaminones for direct-functionalization reactions. It provides immediate access to arylpiperidine, indolizidine, and quinolizidine scaffolds from the corresponding mono- and bicyclic, unattenuated enaminones.
Direct Hiyama Cross-Coupling of Enaminones With Triethoxy(aryl)silanes and Dimethylphenylsilanol
作者:Lei Bi、Gunda I. Georg
DOI:10.1021/ol202202a
日期:2011.10.21
2,3-Dihydropyridin-4(1H)-ones undergo direct C-H functionalization at C5 In the palladium(II)-catalyzed Hiyama reaction, using triethoxy(aryl)silanes and dimethylphenylsilanol. The reagent CuF2 has a dual role In the reactions with triethoxy(aryl)silanes. It Is a source of fluoride to activate the sllane in the Hiyama reaction and also serves as the reoxidant to convert Pd(0) to Pd(II) In the catalytic cycle.