Iodocyclization of Trifluoromethylallenic Phosphonates: An Efficient Approach to Trifluoromethylated Oxaphospholenes.

Abstract α-Trifluoromethylallenic phosphonates were prepared by the reaction of diethyl chlorophosphite (DECP) and 4,4,4-trifluorobut-2-yn-1-ols in the presence of Et 3 N. The iodocyclization of these fluorine-containing allenic phosphonates was achieved with iodine under mild conditions to give the corresponding trifluoromethylated oxaphospholenes in moderate to good yields.