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An efficient route to constructing C–S bonds has been developed by TBHP ( tert-butyl hydroperoxide) mediated C–H thiolation of tetrahydrofuran with disulfides. This route is promoted by catalytic amounts of Na2CO3 and gives various tetrahydrofuran-containing sulfides in moderate to high yields.

An efficient and metal-free method was developed to synthesise 3-sulfenylindoles via the iodine-mediated electrophilic cyclisation of 2-alkynylanilines with disulfides. In the presence of I2, various 3-sulfenylindoles were obtained in moderate to high yields.

A simple and general method for the oxidation of benzylic azides to aldehydes using the inexpensive and environmentally benign iron (III) chloride as catalyst with 30% aqueous H2O2 as oxidant is described. Broad substrate scope and high tolerance against several functional groups make the process synthetically useful.

Water was found to promote the ligand-free Pd(OAc)2-catalysed Heck cross-coupling reaction. In the presence of 3 mol% Pd(OAc)2, 2 equiv. of Cs2CO3 and 15 mg of water, the coupling of a wide variety of aryl halides with alkenes proceeded smoothly in TBAB ( n-Bu4NBr) in moderate to excellent yield. The Pd(OAc)2/TBAB system could be recovered and reused at least three times without loss of catalytic activity.

PdCl2 combined with TBAF (n-Bu4NF) were found to be efficient conditions for the Heck reactions. In the presence of PdCl2 and TBAF, a variety of aryl halides were coupled with alkenes smoothly in moderate to good yields. Moreover, the PdCl2/TBAF system could be recovered and reused several times in the reaction. Note that these reactions are conducted under solvent-free, ligand-free and reusable conditions.