A photocatalyzed formal (3+2) cycloaddition has been developed to construct original polysubstituted α‐SCF3 cyclopentanones in a regio‐ and diastereoselective manner. This building block approach leverages trifluoromethylthio alkynes and branched / linear aldehydes, as readily available reaction partners, in consecutive hydrogen atom transfers and C–C bond formations. Difluoromethylthio alkynes are also compatible subtrates. Furthermore, the potential for telescoped reaction starting from alcohols instead of aldehydes was demonstrated, as well as process automatization and scale‐up under continuous microflow conditions. This prompted density functional theory calculations to support a free radical‐mediated cascade hydrogen atom transfer process.
A photocatalyzed formal (3+2) cycloaddition has been developed to construct original polysubstituted α‐SCF3 cyclopentanones in a regio‐ and diastereoselective manner. This building block approach leverages trifluoromethylthio alkynes and branched / linear aldehydes, as readily available reaction partners, in consecutive hydrogen atom transfers and C–C bond formations. Difluoromethylthio alkynes are also compatible subtrates. Furthermore, the potential for telescoped reaction starting from alcohols instead of aldehydes was demonstrated, as well as process automatization and scale‐up under continuous microflow conditions. This prompted density functional theory calculations to support a free radical‐mediated cascade hydrogen atom transfer process.
Structure–Reactivity Relationship of Trifluoromethanesulfenates: Discovery of an Electrophilic Trifluoromethylthiolating Reagent
作者:Xinxin Shao、Chunfa Xu、Long Lu、Qilong Shen
DOI:10.1021/jo502645m
日期:2015.3.20
A family of electrophilic trifluoromethanesulfenates was prepared. Structure–reactivity relationship studies showed that the substituted groups on the aryl ring of the trifluoromethylthiolating reagent did not have an obvious influence on their reactivities. A simplified electrophilic trifluoromethylthiolating reagent 1c was then identified that can react with a wide range of nucleophiles such as Grignard
A copper-catalyzed chemo- and stereoselective oxidative bis-trifluoromethylthiolation of propiolic acid derivatives was achieved by using carboxylicacid as the activating group and formic acid as a cosolvent. The reaction of propiolic acid derivatives and AgSCF3 in the presence of (NH4)2S2O8 and catalytic Cu(OAc)2 in MeCN/HCO2H afforded bis-trifluoromethylthiolated acrylic acids in moderate to excellent
通过使用羧酸作为活化基团和甲酸作为助溶剂,实现了丙酸衍生物的铜催化的化学和立体选择性氧化双三氟甲基硫醇化。丙酸衍生物和AgSCF 3在(NH 4)2 S 2 O 8和催化性Cu(OAc)2存在下于MeCN / HCO 2 H中反应,可得到中等收率至优异收率的双三氟甲基硫代丙烯酸,并具有E选择性。所得产物的进一步衍生得到一系列含多取代的SCF 3的烯烃。
Base-Catalyzed Electrophilic Trifluoromethylthiolation of Terminal Alkynes
作者:Sébastien Alazet、Luc Zimmer、Thierry Billard
DOI:10.1002/anie.201305179
日期:2013.10.4
Pin the tail on the alkyne: CF3S‐ or CF3CF2S‐alkynes can be simply and quickly obtained by mixing terminalalkynes with a trifluoromethanesulfenamide reagent. The reaction uses easy‐to‐handle reagents, and functions under mild conditions without activation by transition metals.
Copper‐catalyzeddirect perfluoroalkylthiolation of alkynes by using the corresponding perfluoroalkanesulfenamide reagent is reported. The selective mono‐ and bis‐perfluoroalkylthiolation of alkynes can be conducted under very mild conditions (no base, room temperature) in very good to excellent yields. This approach, which uses a low toxicity, inexpensive copper catalyst that incorporates a commercially
Metal-Free Oxidative Trifluoromethylthiolation of Terminal Alkynes with CF<sub>3</sub>SiMe<sub>3</sub> and Elemental Sulfur
作者:Chao Chen、Lingling Chu、Feng-Ling Qing
DOI:10.1021/ja305801m
日期:2012.8.1
A metal-free oxidative trifluoromethyl-thiolation of terminalalkynes using readily available CF(3)SiMe(3) and elemental sulfur at room temperature has been developed. This reaction provides an efficient and convenient method for the preparation of alkynyl trifluoromethyl sulfides bearing a wide range of functional groups. Preliminary investigation revealed that elemental sulfur instead of air acted