One-Pot Regioselective Synthesis of Chromanyl(phenyl)-λ³-iodanes:  Tandem Oxidative Cyclization and λ³-Iodanation of 3-Phenylpropanols

Abstract

Reaction of 3-phenylpropanol with an activated iodosylbenzene-18-crown-6 complex [PhI(OH)BF4-18C6] in dichloromethane in the presence of BF3-Et2O afforded directly the 6-chromanyl(phenyl)-lambda3-iodane-18C6 complex through tandem oxidative intramolecular cyclization yielding chroman and its regioselective phenyl-lambda3-iodanation.

Diaryliodonium Salts: A Journey from Obscurity to Fame

“…[20] It was subsequently reported that phenylsilane also reacted with BF 3 -activated iodosylbenzene, yielding diphenyliodonium tetrafluoroborate after anion exchange. [21,22] The use of triflic acid (TfOH; trifluoromethane sulfonic acid) in organic solvents was found to be an efficient alternative to the inorganic acids previously used, both for reasons of reactivity and because the products could be easily isolated as triflate salts without anion exchange. In 1992, Kitamura et al reported that triflic acid activates iodosylbenzene towards ligand exchange reactions with arenes.…”

Reactions promoted by hypervalent iodine reagents and boron Lewis acids

“…Employing similar reaction conditions, Ochiai demonstrated the tandem oxidative intramolecular cyclisation of 3-phenylpropanol. 42 Formation of 6-chromanyl( phenyl)-λ 3iodanes 28 (Scheme 11, top) originates from the reaction of 15 with either chromane or 3-phenylpropan-1-ol in the presence of BF 3 •OEt 2 . The reported work described the tandem oxidative cyclisation and λ 3 -iodanation of phenylpropanol in which a hypervalent phenyl-λ 3 -iodanyl group was regioselectively introduced at the C6-position of chromane.…”

Recent Advances in Iodosobenzene‐Mediated Construction of Heterocyclic Scaffolds: Transition‐Metal‐Free Approaches and Scope

“…In the same year Ochiai and co‐workers reported a tandem oxidative cyclization and λ 3 ‐iodanation of 3‐phenylpropanols with the aim of construction of chromanyl(phenyl)‐λ 3 ‐iodanes . Exposure of 3‐phenyl‐1‐propanol 11 to either hydroxyl‐λ 3 ‐iodane complex 10 /BF 3 · OEt 2 or PhIO/BF 3 · OEt 2 in dichloromethane at room temperature resulted in 6‐[phenyl(tetrafluoroborato)‐λ 3 ‐iodanyl]chroman 12 [and as a 2:1 complex with 18‐crown‐6 (18C 6 )‐structure 12a ] (Scheme ).…”