Amino acid and water-driven tunable green protocol to access S–S/C–S bonds via aerobic oxidative coupling and hydrothiolation

A green methodology utilizing a natural supplement such as L-arginine in conjunction with water and oxygen led to oxidative coupling of thiols into disulfides (S–S bond) whereas thiol–yne coupling to access vinyl sulfides (C–S bond) was facilitated in a nitrogen atmosphere. The tunable protocol offers several advantages such as low catalyst loading, high yields, clean reaction, no over-oxidation of the S–S bond besides being metal/base/waste-free. The synthesis of ubiquitous cystine and glutathione disulfide in the same catalytic system is an added advantage and the catalytic system has been recycled up to seven times.