Unanticipated switch of reactivity of isonitrile via N C bond scission: Cascade formation of symmetrical sulfonyl guanidine

Unanticipated formation of symmetrical sulfonyl guanidine was observed while treating isonitriles with N,N-dibromoarylsulfonamides in absence of an external amine source. Interesting feature of this work is that one molecule of isonitrile initially reacts with dibromoarylsulfonamide via the C-end to produce the intermediate carbodiimide while the other molecule undergoes C N triple bond cleavage to react as amine source with the intermediate. This switch of reactivity from C-center to N-center of the isonitrile generated symmetrical guanidine.

Automated summary

Unexpectedly, symmetrical sulfonyl guanidine was formed during the treatment of isonitriles with N,N-dibromoarylsulfonamides in absence of an external amine source. The interesting feature of this work is the switch of reactivity from the C-center to the N-center of isonitrile, where one molecule reacts via the C-end to produce an intermediate carbodiimide while the other molecule undergoes C N triple bond cleavage to act as an amine source with the intermediate.