CuI/L‐proline‐catalyzed synthesis of bis(2‐(4,5‐diaryl‐1H‐imidazol‐2‐yl)phenyl)sulfane derivatives using potassium ethylxanthate as a sulfur source.

A CuI/L‐proline‐catalyzed reaction of 2‐(2‐bromophenyl)‐4,5‐diaryl‐1H‐imidazole and potassium ethylxanthate unexpectedly gave bis(2‐(4,5‐diaryl‐1H‐imidazol‐2‐yl)phenyl)sulfane derivatives in high yields, rather than 2,3‐diphenyl‐5H‐benzo[e]imidazo[1,2‐c]thiazine‐5‐thione. This cascade procedure provided an efficient method to synthesize diphenylsulfanes using potassium ethylxanthate as a new type of sulfur source via the Csp2S bond Ullmann reaction twice. [ABSTRACT FROM AUTHOR]