A Convenient Synthesis of Carboxanilides from Silyl Carboxylates and Weakly Nucleophilic Anilines Using<i>p</i>-Trifluoromethylbenzoic Anhydride and a Catalytic Amount of Active Titanium(IV) Salt
Various carboxanilides are prepared in excellent yields from nearly equimolar amounts of silyl carboxylates and the corresponding weakly nucleophilic anilines under mild conditions by using p-trifluoromethylbenzoic anhydride and a catalytic amount of active titanium(IV) salt.
In the presence of a catalytic amount of active titanium(IV) salt generated in situ from 1 mol of TiCl4 and 2 mol of AgOTf, weakly nucleophilic anilines react under mild conditions with nearly equimolar amounts of silyl carboxylates to afford the corresponding anilides in excellent yields using 4-(trifluoromethyl)benzoic anhydride. The mixed anhydride formed in situ from trimethylsily acetate and 4-(trifluoxomethyl)benzoic anhydride, a key intermediate of this reaction, was detected by 1H NMR experiment. Further, it was shown that the reaction of the mixed anhydrides and 2-nitroaniline was faster than that of the corresponding homo anhydrides and 2-nitroaniline.
Amide Formation in One Pot from Carboxylic Acids and Amines via Carboxyl and Sulfinyl Mixed Anhydrides
作者:Bartosz K. Zambroń、Srinivas R. Dubbaka、Dean Marković、Elena Moreno-Clavijo、Pierre Vogel
DOI:10.1021/ol401053y
日期:2013.5.17
An efficient method has been developed for the preparation of yet unknown acyclic mixedanhydrides of carboxylic and sulfinic acids. Sterically hindered 2-methylbut-3-ene-2-sulfinyl carboxylates add primary and secondary amines preferentially onto the carbonyl moieties realizing a new method for the one-pot preparation of carboxamides. It uses 1:1 mixtures of carboxylic acids and amines without a base
The Catalytic Friedel–Crafts Acylation Reaction Starting from Aromatic Compounds and Free Carboxylic Acids (or Their Trimethylsilyl Esters) by Promotion of Silicon(IV) Cationic Species via Mixed Anhydrides
作者:Kaoru Suzuki、Hideo Kitagawa、Teruaki Mukaiyama
DOI:10.1246/bcsj.66.3729
日期:1993.12
active cationic species generated from silicon(IV) chloride and silver perchlorate, carboxylic acids or their trimethylsilyl esters react with p-trifluoromethylbenzoic anhydride to form corresponding mixed anhydrides in situ. Then the catalytic Friedel–Crafts acylation reaction between initially formed mixed anhydrides and coexisted aromatic compounds smoothly proceeds at room temperature to afford
Various carboxylic esters are prepared in excellent yields by the reaction of nearly equimolar amounts of silyl derivatives of carboxylicacids and alcohols with p-trifluoromethylbenzoic anhydride in the presence of a catalytic amount of Lewis acid.