Synthesis utilizing reducing ability of carbon monoxide: a new method for selective synthesis of diorgano selenides and diselenides using selenium-carbon monoxide-water reaction system

Abstract

A new approach to the synthesis of diorganyl selenides and diselenides is described. Selective generation of tertiary amine salts of hydrogen selenide ([HSe − ]•[R 3 NH + ]) and hydrogen diselenide ([HSe 2 − ]•[R 3 NH + ]= has been achieved by controlling the reaction conditions for the reduction of elemental selenium with carbon monoxide and water in the presence of tertiary amine. Subsequent alkylation provided a wide variety of symmetrical dialkyl selenides (R 2 Se) and diselenides (R 2 Se 2 ) with a high degree of selectivity. Acylation of the amine salt of hydrogen selenide by equimolar amounts of acid chlorides led to the formation of tertiary amine salt of selenocarboxylates [R 3 NH + ]•[RCOSe − ] in excellent yields. Further acylation and alkylation of this salt yielded bis(acyl) selenides [(RCO) 2 Se] and Se-alkyl selenocarboxylates (RCOSeR'), respectively. Moreover, oxidation of the amine salt of selenocarboxylates gave rise to bis(acyl) diselenides [(RCO) 2 Se 2 ]