Phenylselenol esters

Acyl radicals. Tributyltin hydride in combination with AIBN can generate acyl radicals from phenylselenol esters, which are a better source than acyl chlorides or phenylthiol esters for acyl radicals for intramolecular cyclization. 

Phenyl selenocyanate, CoHsSeCN. Mol. wt. 182.08, b.p. 125°/16 mm. Preparation. Selenol esters, RCOSeCeH. Carboxylic acids react with phenyl selenocyanate (1 equiv.) and tri-n-butylphosphine (2 equiv.) in methylene chloride or THF to form phenylselenol esters usually in high yield. Similarly, thiol esters,... 

Diisobutylaluminum phenylselenolate (39), which is prepared in situ by the reaction between diphenyl diselenide and diisobutylaluminum hydride (DIBALH) [67], is also a useful nucleophilic selenium reagent (Scheme 37). For example, 39 reacts with oxime sulfonates to produce selenoimidic esters... 

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