Abstract
Useful and applicable methods for one-pot and odorless synthesis of unsymmetrical
and symmetrical diaryl sulfides via C–O bond activation are presented. First, a new
efficient procedure for the synthesis of unsymmetrical sulfides using the cross-coupling
reaction of phenolic esters such as acetates, tosylates, and triflates and with arylboronic
acid or triphenyltin chloride as the coupling partners is reported. Depending on the
reaction, S8/KF or S8/NaOt-Bu system is found to be an effective source of sulfur in the presence of copper
salts and in poly(ethylene glycol) as a green solvent. Then, the synthesis of symmetrical
diaryl sulfides from phenolic compounds by using S8 as the sulfur source and NaOt-Bu in anhydrous DMF at 120 °C under N2 is described. By these protocols, the synthesis of a variety of unsymmetrical and
symmetrical sulfides become easier than the available protocols in which thiols and
aryl halides are directly used for the preparation of the sulfides.
Key words
phenolic esters - arylboronic acid - triphenyltin chloride - copper salt - catalyst
- sulfides
