Synthesis of carboxylic acids by oxidation of alkenes and hydration of alkynes
The OsO4-catalyzed direct oxidation of olefins via the carbon-carbon cleavage of an osmate ester by the action of oxone allows the preparation of ketones or carboxylic acids in high yields. This method should be applicable as an alternative to ozonolysis.
B. R. Travis, R. S. Narayan, B. Borhan, J. Am. Chem. Soc., 2002, 124, 3824-3825.
Oxidative cleavage of various olefins to the corresponding ketones/carboxylic acids occurs with catalytic amounts of 3,4,5,6-tetramethyl-2-iodobenzoic acid (TetMe-IA) and oxone as terminal oxidant in acetonitrile-water mixture at rt. The reaction mechanism involves dihydroxylation of the olefin with oxone, oxidative cleavage by TetMe-IBX, and oxidation of the aldehyde functionality to the corresponding acid with oxone.
J. N. Moorthy, K. N. Parida, J. Org. Chem., 2014, 79, 11431-11439.
A mild one-pot ozonolysis-oxidation process enables the synthesis of carboxylic acids from alkenes. Conducting the ozonolysis in an aqueous organic solvent eliminates secondary ozonide formation and the intermediates generated are readily converted into a carboxylic acid by adding sodium chlorite. The desired acids are isolated in high purity and high yield by simple extraction after a reductive quench.
B. M. Cochran, Synlett, 2016, 27, 245-248.
A catalytic amount of a composite material, RuO2/BaTi4O9, in combination with NaIO4 in EtOAc-H2O has been shown to efficiently cleave alkenes, affording ketones, aldehydes and/or carboxylic acids in high yields.
H. Okumoto, K. Ohtsuko, S. Banjoya, Synlett, 2007, 3201-3205.
A highly enantioselective and catalytic vinylation of aldehydes leads to allylic alcohols that are then transformed to the allylic amines via Overman's [3,3]-sigmatropic rearrangement of imidates. Oxidative cleavage of the allylic amines furnishes amino acids in good yields and excellent ee's. The scope and utility of this method are demonstrated by the synthesis of challenging allylic amines and their subsequent transformation to valuable nonproteinogenic amino acids, including both D and L configured (1-adamantyl)glycine.
Y. K. Chen. A. E. Lurain, P. J. Walsh, J. Am. Chem. Soc., 2002, 124, 12225-12231.
Specific oxidation protocols have been developed for the cleavage of styrenes, aliphatic olefins, and terminal aliphatic olefins to carbonyl compounds with ruthenium trichloride as catalyst. Olefins that are not fully substituted are converted to aldehydes rather than carboxylic acids.
D. Yang, C. Zhang, J. Org. Chem., 2001, 66, 4814-4818.