Hexyl triazabutadiene as a potent alkylating agent

Alkyl diazonium ions are among the most reactive alkylating agents in the synthetic chemists’ arsenal. That said, there are precious few methods by which one can selectively and safely utilize this chemistry. Herein, we show the use of a bench stable hexyl triazabutadiene as a source of reactive diazonium ions that undergo substitution chemistry with weak nucleophiles, such as carboxylates and even sulfonates. In the absence of a nucleophile, elimination was observed to occur. To overcome issues stemming from side-product inhibition of the reaction, we show that the triazabutadiene can be pre-activated with tosyl isocyanate.