A convenient synthesis of fluoroalkyl-substituted heterocycles includi
ng 3-trifluoromethylpyrazoles 7, 5-trifluoromethylisoxazoles 8 and 4-t
rifluoromethylpyrimidines 9 is described. This two-step sequence consi
sts of a radical addition of fluoroalkyl iodides I to alkynes 2 to aff
ord the corresponding alkenes 3 and condensation of 3 with hydrazine,
hydroxylamine or amidines to give the aforementioned heterocycles, res
pectively. A possible pathway is suggested.