Hydroxy-arylthio-addition

Hydroxysulfenylation (Addition of Oxygen, Sulfur) Hydroxy-arylthio-addition (overall transformation)... 

A hydroxy and an arylthio group can be added to a double bond by treatment with an aryl disulfide and lead tetraacetate in the presence of trifluoroacetic acid." Manganese and copper acetates have been used instead of Pb(OAc)4. ° Addition of the groups OH and RSO has been achieved by treatment of alkenes with O2 and a thiol (RSH)." Two RS groups were added, to give vie- dithiols, by treatment of the alkene with a disulfide RSSR and Bp3-etherate."° This reaction has been carried... 

Acylation of a simple thiol with an alkyl carboxylate is not a very suitable method for preparation of S-alkyl thiocarboxylates. Transesterification is, however, possible if either the thiol or the carboxylic ester is activated. The enhanced reactivity of boron, aluminum and silicon thiolates has been utilized for the synthesis of a large variety of thiocarboxylic S-esters, including hydroxy derivatives (from lactones). a,P-Unsaturated thiol esters, e.g. cinnamoyl or 2-butenoyl derivatives, are also accessible. Michael addition, an undesirable side reaction of thiols, is completely avoided if alkyl trimethylsilyl sulfides ortris(arylthio)boranes are applied. ... 

Other Reactions. Treatment of an active hydroxy compound with 2,2 -dipyridyl disulfide and n-BuyP yields the corresponding thiopyridyl derivative. This methodology has been applied to the preparation of 5-arylthio-5 -deoxyribonucleosides (eq 8). Monophosphate esters [R0P(0)(0H)2] will react similarly to form the activated triphenylphosphonium adduct, which, in the absence of an added external nucleophile, dimerizes yielding a pyrophosphate. A-Methylimidazole has been found to catalyze this transformation. The addition of alcohols or amines, however, traps the phosphoryloxyphosphonium salt as the mixed diphosphate ester or mixed ester/amide, respectively (eq 9). Chlorotrimethylsilane and (pyS)2 have also been reported to facilitate the oxidation of phosphites to phosphates. ... 

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