Synthesis of Billard-Langlois Reagents and their Derivatives by Copper-CatalyzedN-Trifluoromethylthiolation of Arylamines with a Trifluoromethanesulfonyl Hypervalent Iodonium Ylide

Synthesis of Sulfur Perfluorophenyl Compounds Using a Pentafluorobenzenesulfonyl Hypervalent Iodonium Ylide

A novel pentafluorobenzenesulfonyl hypervalent iodonium ylide 3 was designed and synthesized as a useful tool for the preparation of sulfur pentafluorophenyl compounds containing a C₆F₅S or C₆F₅SO₂ unit. Electrophilic pentafluorophenylthiolation of enamines, formal [3+2] cycloaddition reaction of nitriles and alkynes, and intramolecular S_NAr cyclization were achieved using iodonium ylide 3. The fluoro-click reaction was also demonstrated using one of the products via an intermolecular S_NAr reaction with heterocentered nucleophiles.

N-Trifluoromethylthio-dibenzenesulfonimide: A Shelf-Stable, Broadly Applicable Electrophilic Trifluoromethylthiolating Reagent

The super electrophilicity of a shelf-stable, easily prepared trifluoromethylthiolating reagent N-trifluoromethylthio-dibenzenesulfonimide 7 was demonstrated. Consistent with the theoretical prediction, 7 exhibits reactivity remarkably higher than that of other known electrophilic trifluoromethylthiolating reagents. In the absence of any additive, 7 reacted with a wide range of electron-rich arenes and activated heteroarenes under mild conditions. Likewise, reactions of 7 with styrene derivatives can be fine-tuned by simply changing the reaction solvents to generate trifluoromethylthiolated styrenes or oxo-trifluoromethylthio or amino-trifluoromethylthio difunctionalized compounds in high yields.

Advances in Synthetic Applications of Hypervalent Iodine Compounds

The preparation, structure, and chemistry of hypervalent iodine compounds are reviewed with emphasis on their synthetic application. Compounds of iodine possess reactivity similar to that of transition metals, but have the advantage of environmental sustainability and efficient utilization of natural resources. These compounds are widely used in organic synthesis as selective oxidants and environmentally friendly reagents. Synthetic uses of hypervalent iodine reagents in halogenation reactions, various oxidations, rearrangements, aminations, C-C bond-forming reactions, and transition metal-catalyzed reactions are summarized and discussed. Recent discovery of hypervalent catalytic systems and recyclable reagents, and the development of new enantioselective reactions using chiral hypervalent iodine compounds represent a particularly important achievement in the field of hypervalent iodine chemistry. One of the goals of this Review is to attract the attention of the scientific community as to the benefits of using hypervalent iodine compounds as an environmentally sustainable alternative to heavy metals.

2-Diazo-1-phenyl-2-((trifluoromethyl)sulfonyl)ethan-1-one: Another Utility for Electrophilic Trifluoromethylthiolation Reactions

2‐Diazo‐1‐phenyl‐2‐((trifluoromethyl)sulfonyl)ethan‐1‐one (diazo‐triflone) (2) is not only a building block but also a reagent. In this study, diazo‐triflone, which was originally used for the synthesis of β‐lactam triflones as a trifluoromethanesulfonyl (SO₂CF₃) building block under catalyst‐free thermal conditions, is redisclosed as an effective electrophilic trifluoromethylthiolation reagent under copper catalysis. A broad set of enamines, indoles, β‐keto esters, pyrroles, and anilines were nicely transformed into corresponding trifluoromethylthio (SCF₃) compounds in good to high yields by diazo‐triflone under copper catalysis via an electrophilic‐type reaction. A coupling‐type trifluoromethylthiolation reaction of aryl iodides was also realized by diazo‐triflone in acceptable yields.

Quantitative Scale for the Trifluoromethylthio Cation-Donating Ability of Electrophilic Trifluoromethylthiolating Reagents

A new parameter, trifluoromethylthio cation-donating ability (Tt(+)DA), is introduced as a quantitative descriptor for the propensity of electrophilic trifluoromethylthiolating reagents to transfer a CF3S moiety in organic synthesis. The first Tt(+)DA scale of popular reagents has been established through DFT calculations. Excellent correlation has been identified between the Tt(+)DAs of N-SCF3-type reagents and the pKa of the corresponding acids, offering a powerful avenue for the rational design of novel reagents.

Oxidative trifluoromethylthiolation and thiocyanation of amines: a general approach to N–S bond formation

Herein, we described a practical and efficient one-pot oxidative trifluoromethylthiolation of amines.

Reactions of allyl alcohols and boronic acids with trifluoromethanesulfonyl hypervalent iodonium ylide under copper-catalysis

Trifluoromethylsulfinyl 3 and trifluoromethylthio 5 compounds are independently obtained by using the sulfone-type reagent 1 under Cu catalysis.