A solvent-free carbonylation and oxidation system aimed at green and sustainable chemistry was developed. With these reactions, an environmentally benign synthesis of urea derivatives could be carried out in good to excellent yields from primary amines and sulfur at ambient pressure of carbon monoxide and oxygen. For example, N,N′-dioctylurea was prepared in 99% yield from two equivalents octylamine and one equivalent sulfur in the presence of carbon monoxide (1 atm) at 80 °C and oxygen (1 atm) at room temperature, in the complete absence of solvent.
urea derivatives - carbon monoxide - oxygen - sulfur - solvent-free