Thermal decomposition of sulphenyl carboxylates

Novel ipso-Substitution of p-Sulfinylphenols through the Pummerer-Type Reaction: A Selective and Efficient Synthesis of p-Quinones and Protected p-Dihydroquinones

“…However, alkenes such as styrene, 3,3-dimethylbut-1-ene, and allyltrimethylsilane efficiently trapped 13 to dramatically increase the yield of 14c (runs 1−3, Table ) 31c. Although about 10−20% of the trifluoroacetate 14 decomposed during purification by flash column chromatography on SiO 2 , we could obtain an excellent yield of the corresponding acetate by the hydrolysis of 14 followed by acetylation (see the Experimental Section).…”

“…Since it is thought that the attack of the trifluoroacetoxy anion on the sulfur atom of the intermediate D gives 14 and the sulfenyl trifluoroacetate 13 [indeed, the addition of 3 equiv of trifluoroacetic acid slightly improved the yield of 14c (run 11, Table ) 29 ], formation of 5 must be due to the reaction of 13 with unreacted 6 . This was confirmed by the fact that treatment of 6c with 13 in situ prepared from silver trifluoroacetate and phenylsulfenyl chloride at 0 °C immediately gave 5c in 70% yield (Scheme ) …”

Silver-Catalyzed Direct Thiolation of Quinones by Activation of Aryl Disulfides to Synthesize Quinonyl Aryl Thioethers

“…With these results, we proposed a plausible mechanism shown in Scheme . Initially, silver complex [Ag­(I)­(dppp)]­OAc ( 5 ) interacting with phenyl disulfide ( 2a ) forms the active intermediate 6a , which then generates silver thiolate 7 and sulphenyl acetate 8 . The reaction of silver thiolate 7 with 1,4-naphthoquinone ( 1a ) forms complex 9 , and it was then oxidized by sulphenyl acetate 8 to afford the desired thioether 3a .…”