Direct, Rapid and Convenient Synthesis of Esters and Thioesters Using PPh₃/N-Chlorobenzotriazole System

Direct and Facile Synthesis of Acyl Isothiocyanates from Carboxylic Acids Using Trichloroisocyanuric Acid/Triphenylphosphine System

“…compare entries 2-7 with 8-12). This novel direct isothiocyanation method can be applied efficiently for the conversion of cinnamic acid, substituted cinnamic acids and aliphatic carboxylic acids to the corresponding acyl isothiocyanates ( Table 2, entries [13][14][15][16][17][18][19][20]. The isothiocyanation of aliphatic carboxylic acids was completed in longer reaction time than the aromatic carboxylic acids.…”

“…Also, carboxylic acids with sensitive functional groups such as alkyl, ether, amide and ester wherein the previously described protocols would not work, can be converted efficiently to corresponding acyl isothiocyanates (Table 2, entries 8,9,10,11,12,18,19,20).…”

“…[19][20][21] Herein we wish to report a simplified, rapid and one-step method for the conversion of carboxylic acids to acyl isothiocyanates in the presence of TPP/TCCA as a mild, efficient and inexpensive reagent system at room temperature.…”

A novel and highly efficient esterification process using triphenylphosphine oxide with oxalyl chloride

“…In the Mitsunobu reaction, the alcohol was usually activated towards nucleophilic attack from the carboxylic acid, and this activation was achieved by the reaction with a phosphine, typically Ph 3 P, and a dialkyl azodicarboxylate. In recent years, a number of reports have focused on generating other azo dicarboxylates such as diisopropyl azodicarboxylate [ 2 , 22 ], di-2-methoxyethyl azodicarboxylate [ 23 ], azodicarbonyl dimorpholide [ 24 ], di- p -nitrobenzyl azodicarboxylate [ 25 ], 5,5′-dimethyl-3,3′-azoisoxazole [ 26 ], 4-dimethylaminopyridine [ 27 , 28 ], di- p -chlorobenzyl azodicarboxylate [ 29 ], DEAD [ 30 ], N -chlorobenzotriazole [ 31 ] and Fe(Pc) [ 32 ].…”

“…Phosphonium, phosphinic salts and phosphine oxides as frequently used coupling reagents have been reported especially for some famous reactions such as the Wittig reaction [5][6][7][8][9][10], Appel reaction [11][12][13][14], Staudinger reaction [15][16][17][18][19][20] and Mitsunobu reaction [2,[21][22][23][24][25][26][27][28][29][30][31][32]. The Mitsunobu reaction, first reported by Mitsunobu et al in 1967 [21], converts an alcohol into a variety of other functional groups including esters, and this method could generate esters in excellent yield (90%) via the condensation of a carboxylic acid and alcohol with a mixture of triphenylphosphine (Ph 3 P) and diethyl azodicarboxylate (DEAD).…”