Iodocyclisation and rearrangement reactions of mono-protected allyl substituted guanidines

The iodocyclisation of a range N-allyl and N-homoallylguanidines using I2/K2CO3 has been found to lead to a series of novel heterocycles which undergo selective rearrangements on variation of the reaction conditions, and predictable protecting group migration in the presence of trifluoroacetic acid in methanol.