Synthesis of symmetrical diaryl 1,2-diketones from grignard reagents and 1,1′-Oxalylimidazole
Reaction of two equivalents of aryl Grignard with 1,1′-oxalyldiimidazole yields diaryl-1,2-diketones (benzils) in 55–80% yield, even for relatively sterically hindered examples.
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Cited by (19)
Zinc azaphthalocyanines with thiophen-2-yl, 5-methylthiophen-2-yl and pyridin-3-yl peripheral substituents: Additive substituent contributions to singlet oxygen production
2009, Dyes and PigmentsCitation Excerpt :However, many heterocyclic aldehydes do not undergo benzoin condensation [30] but the reactivity seems difficult to predict [16]. A second method for synthesis of α-diketones is acylation of the heterocycle with oxalyl chloride [17] or with 1,1′-oxalyldiimidazole [20]. A third possibility is formation of an anil from the heterocyclic carboxaldehyde, followed by cyanide catalyzed condensation to the dianil, and finally acid hydrolysis to the α-diketone [19,31].
Synthesis and biological activity of vicinal diaryl-substituted 1H-imidazoles
2007, TetrahedronCitation Excerpt :In recent years, the efficient synthesis of 1,2,5-triaryl-1H-imidazoles 37 has brilliantly been achieved by regioselective direct transition metal-mediated arylation of 1-aryl-1H-imidazoles84 or 1,2-diaryl-1H-imidazoles.83,100 Thus, Sezen and Sames100 synthesized compounds 37b and 37h by C-5 arylation of 1,2-diphenyl-1H-imidazole (10a) with the required aryl iodides under the optimized conditions originally reported by Miura203 for 2-phenyloxazole, 2-methylthiazole, and 1,2-dimethyl-1H-imidazole (Scheme 52). 1,2,5-Triaryl-1H-imidazoles 37i and 37j have analogously been prepared from 1,2-diaryl-1H-imidazoles 47o and 47p, respectively (Scheme 53).100
Synthesis of unsymmetrical hetaryl-1,2-diketones
2002, TetrahedronA direct access to α-diones from oxalyl chloride
1995, Tetrahedron LettersDiphenylparabanic acid as a synthon for the synthesis of α-diketones and α-ketocarboxylic acids
2012, Journal of Organic Chemistry