Synthesis of 1,2-diketones
A convenient Pd-catalyzed reaction of aryl halides, tert-butyl isocyanide as the CO source, and organoaluminum reagents provides 1,2-diketones in very good yields and with good functional group tolerance.
B. Chen, X.-F. Wu, Org. Lett., 2020, 22, 636-641.
A selective C-C bond cleavage of 1,3-diketones affords 1,2-diketones in high yields under mild reaction conditions in air by the use of FeCl3 as the catalyst and tert-butyl nitrite (TBN) as the oxidant without the use of solvent. The possible reaction mechanism is discussed. This protocol provides an expeditious route to useful 1,2-diketones.
L. Huang, K. Cheng, B. Yao, Y. Xie, Y. Zhang, J. Org. Chem., 2011, 76, 5732-5737.
Iodine/base-catalyzed aerobic photooxidation of 1,3-diketones under visible-light irradiation of fluorescent lamp enables a catalytic direct synthesis of 1,2-diketones.
N. Tada, M. Shomura, H. Nakayama, T. Miura, A. Itoh, Synlett, 2010, 1979-1983.
1,3-Diols undergo smooth oxidative cleavage of the C-C bond in the presence of 2-iodoxybenzoic acid (IBX) affording 1,2-diketones in excellent yields under mild conditions.
J. S. Yadav, S. K. Biswas, R. Srinivas, Synthesis, 2006, 4237-4241.
An aerobic decomposition of 1,3-diaryl-2-diazo-1,3-diketones to 1,2-diaryl-1,2-diketones (benzils) can be catalyzed by a few dirhodium carboxylates (5 mol %) under a balloon pressure of oxygen at ambient temperatures. An oxygen atom from O2 is shown to be incorporated into the product accompanied by the extrusion of a carbonyl unit from the starting materials.
J.-L. Zhu, Y.-T. Tsai, J. Org. Chem., 2021, 86, 813-828.