Switchable Regioselective 7- endo or 6- exo Iodocyclization of O -Homoallyl Benzimidates.

We present a facile switchable regioselective 7- endo or 6- exo iodocyclization of O -homoallyl benzimidates here, which affords various iodo-substituted 1,3-oxazines and tetrahydro-1,3-oxazepines in a controllable manner. The products can further undergo substitution reactions to afford a series of rich functionalized target heterocyclic molecules. The developed protocol has the advantages of mild conditions, simple operation, and excellent functional group compatibility.