A concise and efficient method has been developed herein for the synthesis of valuable naphtho[1,2-d]imidazole derivatives. It involves an earth-abundant cobalt-catalyzed electrophilic ortho C–H amination/cyclization/directing group removal cascade with O-benzoloxyamines using paraformaldehyde as a one carbon synthon. Picolinamide has been utilized as a traceless directing group. A boosting effect of HFIP is found in the whole process. The reaction conditions are very simple and allow easy handling, making this methodology valuable and appealing.
![Graphical abstract: An HFIP-assisted, cobalt-catalyzed three-component electrophilic C–H amination/cyclization/directing group removal cascade to naphtho[1,2-d]imidazoles](http://hg.y866.cn/compound/lib/scimg/usr/1/D3CC00749A.jpg)