Fluorinated Isocyanates and Their Derivatives as Intermediates for Biologically Active Compounds

Fluorinated aromatic isocyanates are valuable intermediates for the production of herbicides and insecticides. Unexpected rearrangements during the synthesis of 2‐(trifluoromethyl)phenyl isocyanates provide an entry to N‐trifluoromethylaminobenzoyl fluorides, a novel class of compounds having fungicidal properties. Carbamoyl fluorides, the products of HF addition to isocyanates, undergo ready sulfenylation. Use of these intermediates for the synthesis of N‐sulfenylcarbamate insecticides led to the discovery of the new principle of detoxification of carbamates by sulfenylation.