Synthesis of N1,N3-disubstituted formamidrazones via the TMSCl-promoted reaction of isocyanides with thiosemicarbazones

A hitherto undescribed TMSCl-promoted reaction of thiosemicarbazones was found to give rare N1,N3-disubstituted formamidrazones in fair to excellent yields. The scope of this new reaction was investigated and a plausible mechanism proposed.