Synthesis of N-Trifluoromethanesulfinyl Ketimines by Cascade Trifluoromethylthiolation/Rearrangement of Ketoximes

Abstract

A new and efficient cascade electrophilic trifluoro­methylthio­lation/radical rearrangement reaction of ketoximes is reported using N-trifluoro­methyl­thio-dibenzene­sulfonimide as the SCF3 source without any additives. This simple one-pot reaction provides the corresponding N-trifluoro­methane­sulfinyl ketimine products in good yields with high E selectivity under mild reaction conditions.

Metal‐catalyzed Radical Trifluoromethylthiolation of Aryl Boronic Acids in the Aqueous Phase

“…In the direct trifluoromethylthiolation of arenes, the electrophilic [12][13][14][15][16] and nucleophilic [17][18][19][20][21] methodologies have been considerably successful over the past decade; however, methods involving radicals have not been studied in detail. [22][23][24] The initially discovered radical trifluoromethylthiolating reagents, such as bis(trifluoromethyl)disulfane (CF 3 SSCF 3 ) [25] and trifluoromethanesulfenyl chloride (CF 3 SCl), [26] are highly toxic, thus preventing their further use.…”

C–H Fluoroalkylsulfinylation/Intramolecular Rearrangement for Precise Synthesis of Fluoroalkyl Sulfoxides

“…Systematic studies on the development and universal applications of bench-stable and readily accessible electrophilic fluoroalkylthiolating reagents have largely extended the space of fluorine and sulfur chemistry, which enable unprecedently quick and direct synthesis of fluoroalkylthiolated target molecules (Figure c) . Indeed, cascade electrophilic fluoroalkylthiolation of an oxygen center/tandem rearrangement reaction, which was mainly developed, provided straightforward routes to prepare diverse fluoroalkyl sulfoxides, owing to the abundance of functionalized alcohols and mild reaction conditions with high efficiency …”

“…[1,3]/[2,3]/[3,3]-Sigmatropic rearrangements have emerged as a prevalent strategy for the precise synthesis of natural and bioactive compounds, while tandem fluoroalkylation and rearrangement reactions of specific substrates, such as ylides, remain to be explored as a result of the scarcity of efficient methods or reactive reagents to form the key intermediates. ,, Owing to the intrinsic weakness of the N–O bond (57 kcal/mol), functionalized arylhydroxylamines have been recognized as powerful building blocks for the preparation of valuable scaffolds with high efficiency . Typically, Lewis acids, transition metals, or elevated reaction temperatures were used to promote the cleavage of the N–O bond and further rearrangements.…”

“…Therefore, we envisioned that arylhydroxylamines could undergo O-fluoroalkylthiolation with shelf-stable and readily accessible electrophilic fluoroalkylthiolating reagents, ,,, resulting in a highly active intermediate containing the “N–O–S” bond (Figure ). Subsequently, internal 2,3-sigmatropic rearrangement through the sulfur and oxygen transfer process and rearomatization occurred to give C–H fluoroalkylsulfenylated products.…”

S-triggered Schmidt-type rearrangement of vinyl azides to access N-aryl-(trifluoromethylsulfinyl)acetamides

“…3 Accordingly, an array of nucleophilic and electrophilic CF 3 S precursors 4 were developed and utilized in diverse trifluoromethylthiolation reactions for the preparation of biologically interesting products. 5 However, a toxic or expensive reagent together with tedious preparatory work poses a challenge to the evolution of attractive trifluoromethylthiolation strategies ensuring diversity, high efficiency and practicability. Therefore, the development of a method for direct installation of a CF 3 S moiety into the target molecules with readily available CF 3 SO 2 Na is an appealing research objective.…”