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
<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
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.
Sulfur and friends: A new electrophilichypervalentiodinereagent 1 has been developed for direct trifluoromethylthiolation. A variety of nucleophiles, including β‐ketoesters, aldehydes, amides, aryl or vinyl boronic acids, and alkynes, reacted with 1 under mild conditions to give the corresponding trifluoromethylthiolated compounds in good to excellent yields.