Electrochemical Synthesis of (Phenylseleno)benzophenones and (Phenyltelluro)benzophenones by the SRN1 Mechanism, Using a Redox Catalyst

Article abstract of DOI:10.1021/jo00232a031

Benzophenone derivatives substituted by o-, m-, or p-phenyltelluro and m- or p-phenylseleno groups have been synthesised in acetonitrile by the mediated cathodic reduction of bromobenzophenone in the presence of an equivalent amount of PhTe- or PhSe- initially prepared by electrochemical reduction of the corresponding diphenyl dichalcogenide.Azobenzene (0.1 equiv) was utilized as redox catalyst.Sonication was maintained during electrolysis and an acid such as fluorene or malononitrile(0.5 equiv) was present to avoid the formation of -CH2CN and its addition upon the bromo or chalcogeno ketones.Under such conditions, the chalcogeno ketones were isolated in 44-86percent yields.In the case of the m- and p-telluro ketones whose yields are moderate (48percent and 44percent), the formation of (PhCOC6H4)2Te proceeded simultaneously (31percent and 36percent).