Sodium nitrite (NaNO2) catalysed iodo-cyclisation of alkenes and alkynes using molecular oxygen

We have developed a convenient iodo-cyclisation reaction using NaNO2 as catalyst and molecular oxygen as the terminal oxidant. The reactive species, acetyl hypoiodite (IOAc), was generated in situ from TBAI and AcOH. The iodo-cyclisation reaction with a range of alkenes and alkynes gave good to excellent yields. Iodo-amination products can also be obtained using carbamates prepared from commercially available allylic alcohols and alkynic alcohols.