Diacyl diselenide

Piperidinium selenocarboxylates (15 equation 10) have been isolated in high yields from the reaction between diacyl diselenides and piperidine. The salts (15) dissolved in common protic and aprotic solvents and readily reacted with alkylating agents such as phenacyl bromide to give the corresponding esters in almost quantitative yields. ... 

L sters, and amides are reduced to 1 -H 0 system. Pyridine derivatives. iqueous THF. With MeOH as a pro-inerted to the diamines. lal selenium is reduced by Sml2, and mium salts gives diacyl diselenide "L r hand, diorganyl disulfides, dise-ieavage, furnishing acyl and alkyl active Michael donors. ... 

In 1994, successful isolations of various alkyl and aryl selenocarboxylic acids [14] enabled them to undergo exact reactions. Reactions of selenocarboxylic acids with dicyclohexylcarbodiimide (DCC) yield the corresponding diacyl selenides 25 and selenourea 26 quantitatively (Scheme 15) [14], as in reactions of thio- [44] and dithiocarboxylic acids [45,46]. In air,selenocarboxylic acids are immediately oxidized to afford the corresponding diacyl diselenides [13, 14]. Also, thio- and dithio-carboxylic acids readily react with aryl isocyanates to give acyl carbamoyl [47,48] and thioacyl carbamoyl sulfides [49, 50], respectively. 

The trialkyls R3M (M=A1, Ga, In) undergo insertion reactions with COS to form alkylmetal thiocarboxylates (RCOS)xMR3 x (M=A1, Ga, In x=l-3), which are difficult to separate [327]. Treatment of trimethylaluminum with thioacetic acid, however, leads to a good yield of dimethylaluminum thioacetate 75 as yellow crystals that sublime (Scheme 6) [327]. On the basis of infrared and NMR spectra, the structure of 78 has been deduced to be a dimer [327]. Syntheses of Group 13 metal derivatives of selenocarboxylic acids have not been reported, although the formation of RCOSeAl(CH3)3 has been described as a short-lived intermediate in the reaction of RCOOR with [(CH3)2Al]2Se to form diacyl diselenide [281]. 

Oxidation of Se-phenyl selenothioates 31 (R=i-Pr, Bu, Tol) with m-CPBA in ether gave a mixture of E- and Z-S-oxides (sulfines) 66, phenylseleno acyl sulfides 67, diphenyl diselenide, and diacyl disulfides 68 (only in the case of R=Tol) (Eq. 17) [12]. It was proposed that compounds 67 were formed by rearrangements of oxathiirane intermediates 69 [12]. 

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