Rhodium-catalyzed substitution reaction of aryl fluorides with disulfides: p-orientation in the polyarylthiolation of polyfluorobenzenes.
In the presence of a catalytic amount of RhH(PPh3)4 and 1,2-bis(diphenylphosphino)benzene, an aromatic fluoride, an organic disulfide (0.5 equiv), and triphenylphosphine (0.5 equiv) reacted in refluxing chlorobenzene to give an aryl sulfide in high yield. Since triphenylphosphine trapped fluoride atoms forming phosphine difluoride, both organothio groups of the disulfide reacted effectively, and the fluoride substituent reacted more readily than the chloride and bromide. The reaction of hexafluorobenzene and a diaryl disulfide gave 1,4-diarylthio-2,3,5,6-tetrafluorobenzene, 1,2,4,5-tetraarylthio-3,6-difluorobenzene, and hexaarylthiobenzene in a stepwise manner; pentafluorobenzene gave 1-arylthio-2,3,5,6-tetrafluorobenzene; 1,2,3,4-tetrafluorobenzene gave 1,2-diarylthio-3,6-difluorobenzene; and 1,2,4,5-tetrafluorobenzene gave 1,4-diarylthio-2-5-difluorobenzene. The polyarylthiolation reaction of polyfluorobenzenes exhibited a strong tendency to form 1,4-difluorobenzenes.
Arisawa
Mieko
M
Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan.
Suzuki
Takaaki
T
Ishikawa
Tomofumi
T
Yamaguchi
Masahiko
M
D002384:Catalysis; D004220:Disulfides / Q000138:chemical synthesis / Q000737:chemistry*; D005464:Fluorobenzenes / Q000138:chemical synthesis / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D004220:Disulfides; D005464:Fluorobenzenes; D009943:Organophosphorus Compounds; D013438:Sulfhydryl Compounds; C061896:triphenylphosphine; D012238:Rhodium