Straightforward Access to 2‑Iodoindolizines via Iodine-Mediated Cyclization of 2‑Pyridylallenes

A metal-free access to 2-iodo-1,3-disubstituted indolizines has been developed. The proposed synthesis is relatively simple and efficient and involves the iodine-triggered 5-endo-trig cyclization of 2-pyridylallene precursors. While it can be conducted on a gram scale, the preparation of the precursors is straightforward and does not always require intermediate purifications. The obtained 2-iodoindolizines can be further functionalized through cross-coupling reactions.