Synthesis and X-ray crystal structure of l-cyano-3,3-bis(trifluoromethyl)-l,3-dihydro-lλ3,2-benzoiodoxole, a stable cyanoiodolane

Stable, crystalline cyanoiodolane 3 has been prepared in two steps by sequential reactions of l-hydroxy-3,3-bis(trifluoromethyl)-l,3-dihydro-lλ³,2-benzoiodoxole 1 with trimethylsilyltriflate and then with cyanotrimethysilane; X-ray structure analysis reveals a distorted T-shaped structure for iodine with an endocyclic I-O bond distance of 2.117 A, which is significantly shorter than usual in C-substituted benzoiodoxole derivatives.