Formation of Oxazolidinones and Oxazinanones by Reaction of Allylamines and of Homoallylamines with Carbon Dioxide and Iodine via Intramolecular Cyclization

“CO2 fixation” has been achieved, under normal pressure at room temperature without a catalyst, by means of the title reaction. The five- and six-membered heterocycles 1 and 2, respectively, are formed in 40–70% yield. Longer reaction time and the addition of Cs2CO3 increases the yields to 60–90% (R1 = H, alkyl, aryl; R2 = H, alkyl; R3 = H, CH2Aryl).