Anodic Oxidation of Bisamides

Previously [1] we studied the anodic oxidation of bisamides of type RCONH(CH2)nNHCOR (n = 2-4) under controlled current electrolysis (CCE), in methanol. Those with 3 and 4 methylene groups undergo mostly mono- and dimethoxylation at the alpha-position to 'N' atom. However, when the spacer contains two methylene groups only the anodic process favor fragmentation products due to CH2-CH2 bond cleavage, as shown in Eq. 1. Following the above results, the anodic oxidation of aromatic bisamides with ‘CH2CH2’ as a spacer (ArCONHCH2CH2NHCOAr), has been investigated [2] in acetonitrile, and under controlled potential electrolysis. The outcome indicates that the major products involve unsymmetrical geminal bisamides (Eq. 2) that are difficult to synthesize by other methods. References [1] T. Golub and J.Y. Becker, Beilstein J. Org. Chem. 2018, 14, 861–868. [2] T. Golub, G.-Y. Dou, C.-C. Zeng and J. Y. Becker, Org. Lett., 2019, 21, 7961-7964 [DOI: 10.1021/acs.orglett.9b02917]. Figure 1