895771-34-3Relevant academic research and scientific papers
Possible competitive modes of decarboxylation in the annulation reactions ofortho-substituted anilines and arylglyoxylates
Laha, Joydev K.,Panday, Surabhi,Tomar, Monika,Patel, Ketul V.
supporting information, p. 845 - 853 (2021/02/09)
Annulation reactions ofortho-substituted anilines and arylglyoxylates in the presence of K2S2O8at 80 °C under metal-free neutral conditions have been investigated, which extended a platform for the tandem synthesis of nitrogen heterocycles. While arylglyoxylic acids are known to undergo decarboxylation to form an acyl radical in the presence of K2S2O8and used in the Minisci acylation of electron-deficient (hetero)aromatics, their reactions with electron-richortho-substituted anilines to form nitrogen heterocycles have recently been studied. Depending upon the experimental conditions used in the reactions, the mechanism of the formation of heterocycles involving reactions of an acyl radical or aryl iminocarboxylic acids has been postulated. Given the subtle understanding of the mechanisms of annulation reactions of 2-substituted anilines and arylglyoxylates in the presence of K2S2O8, an extensive mechanistic investigation was undertaken. In the current study, the various mechanistic pathways including the generation of acyl, imidoyl, aminal, and N,O-hemiketal radicals have been postulated based on different possible decarboxylation modes. Some of the proposed intermediates are supported based on the available analytical data. The protocol uses a single, inexpensive reagent K2S2O8, which offers not only transition-metal-free conditions but also serves as the reagent for the key decarboxylation step. Taken together, this study complements the current development of the annulation reactions of 2-substituted anilines and arylglyoxylates in terms of synthesis and mechanistic understanding.
Syntheses of 3,4- and 1,4-dihydroquinazolines from 2-aminobenzylamine
Díaz, Jimena E.,Ranieri, Silvia,Gruber, Nadia,Orelli, Liliana R.
supporting information, p. 1470 - 1477 (2017/08/02)
A straightforward strategy for the synthesis of dihydroquinazolines is presented, which allows for the preparation of 3,4- and 1,4-dihydroquinazolines with different substitution patterns from 2-aminobenzylamine (2-ABA) as common precursor. The required functionalization of both amino groups present in 2-ABA was achieved by different routes involving selective N-acylation and cesium carbonate-mediated N-alkylation reactions, avoiding protection/deprotection steps. The heterocycles were efficiently synthesized in short reaction times by microwave-assisted ring closure of the corresponding aminoamides promoted by ethyl polyphosphate (PPE).
General, Mild, and Metal-Free Synthesis of Phenyl Selenoesters from Anhydrides and Their Use in Peptide Synthesis
Temperini, Andrea,Piazzolla, Francesca,Minuti, Lucio,Curini, Massimo,Siciliano, Carlo
, p. 4588 - 4603 (2017/05/12)
A mild, practical, and simple procedure for phenyl selenoesters synthesis from several anhydrides and diphenyl diselenide was developed. This transition-metal-free method provides a straightforward entry to storable Fmoc-amino acid selenoesters which are effective chemoselective acylating reagents. An application to oligopeptide synthesis was illustrated.
Tert -Butyl Peroxybenzoate Mediated Selective and Mild N-Benzoylation of Ammonia/Amines under Catalyst- and Solvent-Free Conditions
Yadav, Dilip Kumar T.,Bhanage, Bhalchandra M.
supporting information, p. 1862 - 1866 (2015/08/06)
A new protocol for the synthesis of amides from tert-butyl peroxybenzoate (TBPB) and ammonia/amines has been developed under catalyst- and solvent-free conditions. The ammonia, primary and secondary amines reacted smoothly with TBPB to furnish the corresponding primary, secondary, and tertiary amides in excellent yields. TBPB proved to be an efficient and highly chemoselective benzoylating reagent for aliphatic amines in the presence of aromatic amines/hydroxyl groups.
An azobenzene-containing metal-organic framework as an efficient heterogeneous catalyst for direct amidation of benzoic acids: Synthesis of bioactive compounds
Hoang, Linh T. M.,Ngo, Long H.,Nguyen, Ha L.,Nguyen, Hanh T. H.,Nguyen, Chung K.,Nguyen, Binh T.,Ton, Quang T.,Nguyen, Hong K. D.,Cordova, Kyle E.,Truong, Thanh
supporting information, p. 17132 - 17135 (2015/12/04)
An azobenzene-containing zirconium metal-organic framework was demonstrated to be an effective heterogeneous catalyst for the direct amidation of benzoic acids in tetrahydrofuran at 70°C. This finding was applied to the synthesis of several important, representative bioactive compounds.
A convenient palladium-catalyzed carbonylative synthesis of quinazolines from 2-aminobenzylamine and aryl bromides
Chen, Jianbin,Natte, Kishore,Neumann, Helfried,Wu, Xiao-Feng
, p. 56502 - 56505 (2015/02/02)
A novel and practical strategy towards quinazoline scaffolds synthesis has been achieved. Through palladium-catalyzed carbonylative coupling of 2-aminobenzylamine with aryl bromides, the desired quinazolines were produced in moderate to good yields for the first time. The reactions followed an aminocarbonylation-condensation-oxidation sequence in a one-pot one-step manner. Preliminary investigation showed DMSO serves both as solvent and oxidant in this procedure.
