Phenylcarbonyl isothiocyanates, substituted

Heating of the cycloadduct derived from 4-nitrophenyl isothiocyanate and dicyclohexyl-carbodiimide causes cycloreversion to give the starting materials In the reaction of phenylcarbonyl isothiocyanate and substituted phenylcarbonyl isothiocyanates, respectively, with carbodiimides, [2-1-4] cycloadducts 221 are usually obtained, but the [2 + 2] cycloadduct 220 is also formed when the reaction of DCC with phenylth-iocarbonyl isothiocyanate is stopped at shorter reaction times. ... 

Cyclohexyl-2(2 -thienyl)-3-benzoylaziridine also reacts with aryl isothiocyanates to give [3-1-2] cycloadducts The reaction of A -tosylaziridines with isothiocyanates in the presence of tributylphosphine affords the [3+2] cycloadducts in yields up to 78 Phenylcarbonyl isothiocyanates react with 1,3-dipoles 99, generated in the treatment of 4-substituted 1,2,3-thiadiazoles with KOH/EtOH, to give the heterocycle 100 . 

Cyclic aldo- and ketonitrones react similarly with phenyl isothiocyanateHowever, substituted phenyl isothiocyanates react with 5,5-dimethyl-l-pyrroline-l-oxide to give cycloadducts derived from addition across the C=N bond as well as the C=S bond of the isothiocyanates. The C=S cycloadducts are unstable and undergo further transformations . The [3+2] cycloaddition reaction of 3,3,5,5-tetramethylpyrroline-l-oxide with aryl- and phenylcarbonyl isocyanates also occurs exclusively by addition across the C=S bond . ... 

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