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.
<i>N</i>-Trifluoromethylthiosaccharin: An Easily Accessible, Shelf-Stable, Broadly Applicable Trifluoromethylthiolating Reagent
作者:Chunfa Xu、Bingqing Ma、Qilong Shen
DOI:10.1002/anie.201403983
日期:2014.8.25
A new, electrophilic trifluoromethylthiolating reagent, N‐trifluoromethylthiosaccharin, was developed and can be synthesized in two steps from saccharin within 30 minutes. N‐trifluoromethylthiosaccharin is a powerful trifluoromethylthiolating reagent and allows the trifluoromethylthiolation of a variety of nucleophiles such as alcohols, amines, thiols, electron‐rich arenes, aldehydes, ketones, acyclic
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
Oxidative Trifluoromethylthiolation of Terminal Alkynes with AgSCF<sub>3</sub>: A Convenient Approach to Alkynyl Trifluoromethyl Sulfides
作者:Sheng-Qing Zhu、Xiu-Hua Xu、Feng-Ling Qing
DOI:10.1002/ejoc.201402533
日期:2014.7
new method for the efficient synthesis of alkynyl trifluoromethyl sulfides was developed. By combining AgSCF3 and NCS in N,N-dimethylacetamide, an electrophilic active intermediate was produced, which was then treated with a variety of terminalalkynes to afford the corresponding trifluoromethanesulfenylated products in moderate to excellent yields.
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.