Catalytic Geminal Difluorination of Styrenes for the Construction of Fluorine-rich Bioisosteres
摘要:
A geminal difluorination of alkenes based on I(I)/I(III) catalysis is disclosed, which is compatible with a range of electronically and substitutionally diverse styrenes (27 examples, up to 89% yield). Employing inexpensive p-Toll as the organocatalyst, turnover is enabled by Selectfluor-mediated oxidation to generate the ArIF2 species in situ. Extension to include alpha-substituted styrenes bearing fluorine-containing groups is disclosed and provides an expansive platform for the generation of fluorine-rich architectures.
Silver-Mediated Intermolecular Iodotrifluoromethoxylation of Alkenes
作者:Qingyun Huang、Pingping Tang
DOI:10.1021/acs.joc.9b03206
日期:2020.2.21
For the first time, intermolecular iodotrifluoromethoxylation between alkenes and NIS with AgF as the catalyst and TFMS as the trifluoromethoxylation reagent has been explored. The practical processes, good functional group tolerance, and easy scalability make this reaction an attractive protocol for the synthesis of trifluoromethoxylated iodides, which can be readily used for further synthetic manipulation
Reported herein is the use of S‐perfluoroalkyl sulfilimino iminiums as a new source of RF radicals under visible‐light photoredox catalysis (RF=CF3, C4F9, CF2Br, CFCl2). These shelf‐stable perfluoroalkyl reagents, readily prepared on gram scale from the corresponding sulfoxide using a one‐pot procedure, allow the efficient photoredox‐induced oxyperfluoroalkylation of various alkenes using fac‐Ir(ppy)3
本文报道了在可见光光氧化还原催化下(R F = CF 3,C 4 F 9,CF 2 Br,CFCl 2)使用S-全氟烷基亚磺酰亚胺基亚胺作为R F自由基的新来源。这些易于储存的全氟烷基试剂可以通过一锅法从相应的亚砜以克为单位轻松制备,可以使用fac-Ir(ppy)3作为光催化剂,对各种烯烃进行有效的光氧化还原诱导的全氟烷基氧化。重要的是,进行了自旋俘获/电子顺磁共振实验以表征参与该自由基/阳离子过程的所有自由基中间体。
An efficient nano-Cu2O-catalyzed cascade multicomponent reaction of 2-halobenzoic acids and trimethylsilyl cyanide with diverse amines was developed using water as a solvent, affording versatile N-substituted phthalimide derivatives in moderate to excellent yields. This novel strategy features carbon monoxide gas-free, environmentallybenign, one-pot multistep transformation, commercially available
the source of SCF3 radical under photoredoxcatalysis. This allowed an efficient and general visible‐light‐mediated carbotrifluoromethylthiolation of alkenes. Under the optimized conditions using fac‐[Ir(ppy)3] as the photocatalyst, various N‐aryl acrylamides as well as a wide range of substituted styrenes can readily be difunctionalized in an intra‐ or intermolecular fashion, affording the corresponding
1-Fluoro-1-sulfonyloxylation of Alkenes by Sterically and Electronically Tuned Hypervalent Iodine: Regression Analysis toward 1,1-Heterodifunctionalization
the heterodifunctionalization of alkenes, 1,1-regioselectivity remains elusive in sharp contrast to 1,2-regioselectivity. Herein, the 1-fluoro-1-sulfonyloxylation of styrenes with Bu4NBF4 and sulfonic acids using a hypervalent iodine ArI(OAc)2 is reported. Regression analysis of substituents on ArI(OAc)2 suggested that their electron-withdrawing ability and steric factor influence the 1,1-heterodifunctionalization
在烯烃的异双功能化中,1,1-区域选择性与 1,2-区域选择性形成鲜明对比,仍然难以捉摸。在此,报道了使用高价碘 ArI(OAc) 2对苯乙烯与 Bu 4 NBF 4和磺酸进行1-氟-1-磺酰氧基化反应。ArI(OAc) 2上取代基的回归分析表明它们的吸电子能力和空间因素影响1,1-异双功能化。我们设计了o -2,4-(CF 3 ) 2 C 6 H 3 }-和p -NO 2 -取代的ArI(OAc) 2通过回归分析实现高选择性。