Electrochemical Diazidation of Alkenes Catalyzed by Manganese Porphyrin Complexes with Second-Sphere Hydrogen-Bond Donors

In this work, we report manganese porphyrin complexes
for the electrocatalytic
vicinal diazidation of alkenes with sodium azide. This protocol shows
improved practicality over our previous work using MnBr2 catalysis in the following aspects: (1) it requires substantially
lower catalyst loading (as low as 0.3 mol %), which reduces the formation
of metal azide complexes and simplifies product purification; (2)
the introduction of a neutral aqueous buffer prevents the generation
of toxic hydrazoic acid, contributing to a safer experimental procedure;
(3) the catalytic system displays improved reactivity toward unactivated
terminal alkenes. Mechanistic studies support the roles of second-sphere
hydrogen-bond donors in stabilizing key reaction intermediates.