Copper‐Catalyzed Synthesis of N‐Formyl/Acylsulfenamides and ‐thiosulfonamides

Recent remarkable success of copper‐catalyzed oxidative bond formations led us to develop an environmentally benign copper‐catalyzed sulfur–nitrogen bond‐forming reaction to provide synthetically and industrially useful electron‐deficient sulfenamides. The low nucleophilicity of N‐formyl/acyl‐ and sulfonylamides was overcome by introducing a 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene additive. A variety of N‐formyl/acylsulfenamides and ‐thiosulfonamides were synthesized in good yields without over‐oxidation of sulfur. Related mechanistic studies supported the proposed reaction mechanism.