Reactions of Sulfur Substituted Carbodiimides

The nucleophilic reactions of N-sulfurcarbodiimides are similar to the nucleophilic reactions of other carbodiimides. However, oligomerization reactions are less pronounced. The cyclic dimer of N-p-toluenesulfonyl-N -phenylcarbodiimide 31 is obtained on dissociation of the cycloadduct 30 obtained in the outlined reaction.  

A trimeric six membered ring cyclotrimer 32 is formed from N-trifluoromethylsulfonyl-N -4-fluorophenylcarbodiimide, which is characterized by hydrolysis to the triazine derivative 

indicating that the trimerization proceeds across the aryl substituted C=N bond.  

Six membered ring cycloadducts of N-sulfonylcarbodiimides with arenesulfonyl isocyanates and dialkylcarbodiimides are also known.  

Reactions of N-sulfonylcarbodiimides with cyclic amidines 34 afford mesoionic cycloadducts 35 or a new sulfonylcarbodiimide 36 depending on the substituents.  

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