Synthesis of Glycouronamides by Transamidation Approach at Room Temperature

Abstract

Synthesis of various glycouronamides via transamidation reaction is reported under mild reaction conditions. Transamidation of N-nitroso uronamides with primary and secondary amines was successfully achieved in the presence of triethyl amine. On the other hand, N-Boc uronamides underwent transamidation smoothly with various primary amines in the presence of DBU. These reactions provided the desired glycouroamides in good to excellent yields at room temperature.

Amidic resonance not a barrier for transamidation of N-pivaloyl activated amides: catalyst, base and additive free conditions

“…3 In the endeavour to achieve transamidation with a broad substrate scope, activation of amides prior to transamidation has been recognized as the most effective and successful method, 1,[3][4][5] in which the amides are activated by coupling an electron-withdrawing group to the amide nitrogen. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] In recent years, transamidation of N-activated acyclic twisted amides has gained wide attention. Among them, the most notable ones are the transition-metal-free transamidations using LiHMDS, 1 Et 3 N, 9,19 DBU, 9,17 TBHP, 20 CsF, 21,22 and CsCO 3 23 and under catalyst-free conditions.…”

“…[6][7][8][9][10][11][12][13][14][15][16][17][18][19] In recent years, transamidation of N-activated acyclic twisted amides has gained wide attention. Among them, the most notable ones are the transition-metal-free transamidations using LiHMDS, 1 Et 3 N, 9,19 DBU, 9,17 TBHP, 20 CsF, 21,22 and CsCO 3 23 and under catalyst-free conditions. 5,10,14,[23][24][25][26][27] To date, transamidation has been primarily achieved with N-activated amides endowed with significant amide bond twists.…”

Microwave-assisted chemoselective transamidation of secondary amides by selective N–C(O) bond cleavage under catalyst, additive and solvent-free conditions

“…[12][13][14] On the other hand, Szostak and co-workers have demonstrated the transamidation of N-tert-butoxycarbonyl (N-Boc), 15,16 N-toluenesulphonate (N-Ts) activated secondary amides with palladium, [17][18][19][20] base catalysts, 21 and recently in the absence of any additives under mild conditions. 22 Recently the transamidation of N-Boc, N-nitroso, N-tosyl, and N-pivaloyl activated primary and secondary amides have been reported without any catalyst under mild conditions [23][24][25][26][27][28] and Xile Hu et al reported the nickel-catalyzed reductive transamidation of secondary amides with nitroarenes as the nitrogen source. 29 Microwave irradiation (MWI) is a non-conventional and environmentally friendly energy source and have been successfully employed recently to promote organic transformations.…”