Tf2NH-Catalyzed 1,6-Conjugate Addition of Vinyl Azides with p-Quinone Methides: A Mild and Efficient Method for the Synthesis of β-Bis-Arylamides

Triflamides and Triflimides: Synthesis and Applications

Among the variety of sulfonamides, triflamides (CF₃SO₂NHR, TfNHR) occupy a special position in organic chemistry. Triflamides are widely used as reagents, efficient catalysts or additives in numerous reactions. The reasons for the widespread use of these compounds are their high NH-acidity, lipophilicity, catalytic activity and specific chemical properties. Their strong electron-withdrawing properties and low nucleophilicity, combined with their high NH-acidity, makes it possible to use triflamides in a vast variety of organic reactions. This review is devoted to the synthesis and use of N-trifluoromethanesulfonyl derivatives in organic chemistry, medicine, biochemistry, catalysis and agriculture. Part of the work is a review of areas and examples of the use of bis(trifluoromethanesulfonyl)imide (triflimide, (CF₃SO₂)₂NH, Tf₂NH). Being one of the strongest NH-acids, triflimide, and especially its salts, are widely used as catalysts in cycloaddition reactions, Friedel–Crafts reactions, condensation reactions, heterocyclization and many others. Triflamides act as a source of nitrogen in C-amination (sulfonamidation) reactions, the products of which are useful building blocks in organic synthesis, catalysts and ligands in metal complex catalysis, and have found applications in medicine. The addition reactions of triflamide in the presence of oxidizing agents to alkenes and dienes are considered separately.

Zn(OTf)2-Catalyzed 1,6-Conjugate Addition of Benzoxazinones to p-Quinone Methides: Access to 3,3-Diaryl-2-(2-oxo-2H-1,4-benzoxazin-3-yl)propanoic Acid Esters

An effective method for the synthesis of 3,3-diaryl-2-(2-oxo-2H-1,4-benzoxazin-3-yl)propanoic acid esters is reported. A novel zinc triflate-catalyzed regioselective 1,6-conjugate addition of vinylogous carbamates to p-quinone methides for accessing the title compounds has been developed. This protocol furnished the hybrid compounds in good to excellent yields. The reaction is rapid and has a broad substrate scope.

Recent developments in 1,6-addition reactions of para-quinone methides (p-QMs)

In this review, we provide a comprehensive overview of recent progress in this rapidly growing field by summarizing the 1,6-conjugate addition and annulation reactions of p-QMs with consideration of their mechanisms and applications.

Silyl enol etherification by a Tf2NH/amine co-catalytic system for minimizing hazardous waste generation

A practical silyl enol etherification of ketones with allylsilanes catalyzed by a Tf₂NH–amine co-catalyst under mild conditions has been developed.