Synthesis of trifluoromethylated pyrrolidines via decarboxylative [3+2] cycloaddition of non-stabilized N -unsubstituted azomethine ylides

One-Pot Synthesis of Triazolobenzodiazepines Through Decarboxylative [3 + 2] Cycloaddition of Nonstabilized Azomethine Ylides and Cu-Free Click Reactions

“…Reaction conditions for the synthesis of proline 4a through one-pot [3 + 2] cycloaddition were developed using 1:1.2:1 of 2-azidebenzaldehyde 1a , 2-aminoisobutyric acid 2a, and N -ethylmaleimide 3a in the presence of 0.3 equiv. of AcOH for decarboxylation [43] (Table 1). After screening solvents including 2-methyltetrahydrofuran, toluene, EtOH and CH 3 CN as well as reaction time and temperature, it was found that a reaction using CH 3 CN as a solvent at 110 °C for 6 h afforded 4a in 93% LC (liquid chromatography) yield with a dr (diastereomer) of 6:1 (Table 1, entry 6).…”

“…Compared to the reactions of stabilized ylides A, cycloadditions of nonstabilized ylides B are less explored (Figure 2B) [36,37,38,39,40,41,42]. We have recently reported the synthesis of α-trifluoromethyl pyrrolidines through decarboxylative [3 + 2] cycloaddition of nonstabilized azomethine ylides B derived from α-amino acids [43]. Presented in this paper is a new application of nonstabilized azomethine ylides in the one-pot [3 + 2] and click reactions for triazolobenzodiazepines.…”

Recent Advances on Diverse Decarboxylative Reactions of Amino Acids

“…Zhang et al. developed a greener method for the synthesis of trifluoromethylated and pyrrolidinedione‐fused pyrrolidines 370 through a three‐component, decarboxylative [3+2] cycloaddition of non‐stabilized N ‐unsubstituted azomethine ylides with trifluoroacetophenones 369 (Scheme ) …”

One-pot Double Annulations to Confer Diastereoselective Spirooxindole-pyrrolothiazoles

“…We have reported a series of multicomponent reactions, like Groebke-Blackburn-Bienayme for making BET inhibitors UMB32 and UMB136 [33,34], and Zhang 4-Aminoquinolines synthesis for developing fluorinated analogues of acetylcholinesterase (AChE) inhibitors [35], cascade reactions, such as one-step synthesis of quinolines and quinolin-4-ols involving Histone acetyltransferases (HAT) inhibitors [36,37], as well as one-pot reactions, for example, amino acids(esters)-based [3+2] cycloadditions [38][39][40][41][42][43][44][45][46][47][48] in the synthesis of pyrrolidine-containing systems [49][50][51][52][53][54][55][56][57][58][59].…”