Iodocyclisations reactions of Boc- and Cbz-protected N-allylguanidines

Abstract The cyclisation of mono-protected and bis-protected guanidines 8a – j under standard iodocyclisation conditions (I 2 /K 2 CO 3 ) gave the guanidine heterocycles 9 – 25 via either a direct cyclisation or by a cyclisation/ring-contraction process, which could be controlled by careful selection of conditions.