Rhodium(III)-Catalyzed Direct C–H Arylation of Various Acyclic Enamides with Arylsilanes
作者:Xiaolan Li、Kai Sun、Wenjuan Shen、Yong Zhang、Ming-Zhu Lu、Xuzhong Luo、Haiqing Luo
DOI:10.1021/acs.orglett.0c03578
日期:2021.1.1
The stereoselective β-C(sp2)–H arylation of various acyclic enamides with arylsilanes via Rh(III)-catalyzed cross-coupling reaction was illustrated. The methodology was characterized by extraordinary efficacy and stereoselectivity, a wide scope of substrates, good functional group tolerance, and the adoption of environmentally friendly arylsilanes. The utility of this present method was evidenced by
only: An atom‐economical synthetic route towards arylated Z‐enamides through double CH functionalization is described. The Z/E selectivity of the palladium‐catalyzed monoarylation is absolute (step A in scheme), and the molecular complexity of the products can be further endowed by a sequential second arylation, which requires the use of trifluoracetic acid (TFA; step B).
Catalytic charge transfer complex enabled difluoromethylation of enamides with difluoromethyltriphenylphosphonium bromide
作者:Ping Li、Qiang Liu、De-Qun Sun、Xiang-Yu Chen
DOI:10.1039/d2ob01539k
日期:——
A catalytic chargetransfercomplex strategy that enabled difluoromethylation and ethoxycarbonylmonofluoromethylation of enamides with phosphonium bromine salts has been reported. This strategy also provides a convenient approach for the synthesis of functionalized oxindoles and 1,1-diphenylethylenes with easily available phosphonium bromine salts and a catalytic amount of iodine anion.
Copper- or iron-catalyzed stereoselective methylation of enamides using dicumyl peroxide as the methyl source
作者:Fukuan Zhang、Haidong Liu、Xin-Jian Jia、Lin Li、Yi Liang、Xuzhong Luo、Haiqing Luo
DOI:10.1039/d3nj02949b
日期:——
An efficient and versatile copper- or iron-catalyzed direct β-C(sp2)–Hmethylation of enamides by usingdicumylperoxide (DCP) as the methylatingreagent has been developed. This methodology provides convenient access to a wide range of β-C(sp2)-methylated enamides with exclusive E-selective control in moderate to good yields. Mechanistic studies reveal that a methyl radical was involved in this transformation
A charge transfer complex (CTC)-enabled photoreduction of ether phosphonium salts for the generation of oxyalkyl radicals was described. The photoreduction provides a convenient method to achieve selective oxyalkylation of enamides with broad substrate scope. The method features operational simplicity, mild and inherent green conditions.