Synthesis of carboxylic acids by hydrolysis of amides and related compounds
A nickel-catalyzed esterification of amides with 2-(trimethylsilyl)ethanol, followed by a fluoride-mediated deprotection in a single-pot operation provides carboxylic acids. This approach circumvents catalyst poisoning observed in attempts to directly hydrolyze amides using nickel catalysis.
R. R. Knapp, A. S. Bulger, N. K. Garg, Org. Lett., 2020, 22, 2833-2837.
tert-Butyl nitrite (TBN) is a multitask reagent for the controlled synthesis of N-nitrosoamides from N-alkyl amides, hydrolysis of N-methoxyamides to carboxylic acids, metal-free benzocoumarin synthesis from ortho-aryl-N-methoxyamides, and Ru-catalyzed isocoumarin synthesis.
S. L. Yedage, B. M. Bhanage, J. Org. Chem., 2017, 82, 5769-5781.
A catalytic amount of ytterbium(III) triflate as a Lewis acid promoter enables the conversion of a broad range of imides in the presence of alcohols, water, amines, or N,O-dimethylhydroxylamine to the corresponding esters, carboxylic acids, amides, and Weinreb amides in good yields.
C. Guissart, A. Barros, L. R. Barata, G. Evano, Org. Lett., 2018, 20, 5090-5093.
Rhodococcus erythropolis AJ270, an amidase-containing microbial whole cell catalyst, enables a highly efficient and enantioselective hydrolytic desymmetrization of a number of prochiral α-substituted α-aminomalonamides in neutral phosphate buffer at 30°C to afford functionalized α-tetrasubstituted α-amino acids in very good chemical yields and high ee.
L-B. Zhang, D.-X. Wang, L. Zhao, M.-X. Wang, J. Org. Chem., 2012, 77, 5584-5591.
2-bromo-6-isocyanopyridine as novel convertible isocyanide for multicomponent chemistry combines sufficient nucleophilicity with good leaving group capacity of the resulting amide moiety under both basic and acidic conditions. An efficient two-step synthesis of the potent opioid carfentanil demonstrates the practical utility of this reagent.
G. van der Heiden, J. A. W. Jong, E. Ruijter, R. V. A. Orru, Org. Lett., 2016, 18, 984-987.