Sébastien Alazet

Abstract Because of its high lipophilicity, the CF 3 S group has always interested chemists. However, strategies to introduce it into organic molecules have been, for the most part, reserved to specialized “fluorine chemists”. Recent published work has demystified these preconceived ideas by proposing new efficient methods or easy‐to‐handle reagents to enrich the toolbox of chemists. However, all these new concepts arise from the pioneering works of the past! In this review, we will do a “back to the future” by remembering the most significant results of the past and by presenting extensions and novelties of the present and for the future.

Pin the tail on the alkyne: CF3S- or CF3CF2S-alkynes can be simply and quickly obtained by mixing terminal alkynes with a trifluoromethanesulfenamide reagent. The reaction uses easy-to-handle reagents, and functions under mild conditions without activation by transition metals. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

A general method for the α-trifluoromethylthiolation of carbonyl compounds, without prefunctionalization, has been developed. Aldehydes, ketones, esters, amides, keto-esters, alkaloids, and steroids have been trifluoromethylthiolated with good yields. This work, proposing a new reagent for electrophilic trifluoromethylthiolation, provides a route towards the original synthesis of various trifluoromethylthiolated molecules for further applications.

Azides are building blocks of increasing importance in synthetic chemistry, chemical biology, and materials science. Azidobenziodoxolone (ABX, Zhdankin reagent) is a valuable azide source, but its safety profile has not been thoroughly established. Herein, we report a safety study of ABX, which shows its hazardous nature. We introduce two derivatives, tBu-ABX and ABZ (azidobenziodazolone), with a better safety profile, and use them in established photoredox- and metal-mediated azidations, and in a new ring-expansion of silylated cyclobutanols to give azidated cyclopentanones.

The most reactive 2nd generation of trifluoromethanesulfenamides undergoes a copper-catalyzed cross-coupling reaction with boronic acids to afford CF3 S-molecules. Contrary to the previous methods in the literature, no base addition, no heating, and no large excess of reagents are required to obtain good results. Furthermore, a crucial role of a small amount of water to favor this reaction has been demonstrated. This constitutes the mildest described conditions for such a reaction.