[14353-86-7] · C6F9IO6 · Iodine Tris(trifluoroacetate) · (MW 465.96)
(formation of trifluoroacetoxy-substituted alkanes,5,6 reacts with alkenes to form bis(trifluoroacetates);10 iodinates arenes;7,8 preparation of iodonium salts via [bis(trifluoroacetoxy)iodo]arenes;9 induces 1,2-migration in arylalkenes;11 formation of a,b-trifluoroacetoxy diesters from cyclic ethers5,12,13)
Alternate Names: ITT; tris(trifluoroacetoxy)iodane.
Physical Data: mp 120 °C (dec).
Solubility: sol CH2Cl2, CHCl3.
Form Supplied in: yellow crystals; not commercially available.
Analysis of Reagent Purity: elemental analysis.4
Preparative Methods: Trifluoroacetic Acid oxidation of Iodine;2 reaction of Silver(I) Trifluoroacetate with ICl3;3 reduction of IO2(CO2CF3) with I2;2 or action of Nitric Acid/Trifluoroacetic Anhydride on I2.4
Purification: sublimation (90 °C/10-3 mmHg).4
Handling, Storage, and Precautions: stable compound; store in the absence of moisture in a sealed container under nitrogen, protected from light. Handle in a fume hood.
Alkanes react rapidly with iodine tris(trifluoroacetate). In the case of cyclohexane, (AcO)3I does not react at rt, but ITT reacts in 3 d (eq 1).5
Alkanes possessing tertiary C-H groups are oxidized within minutes to form trifluoroacetate esters (eqs 2-4).5
8aH-Cedrane reacts rapidly at rt to yield the ring contracted ketone (eq 5).6
The reaction of arenes with ITT leads to introduction of the (CF3CO2)2I group onto the aromatic ring to yield the corresponding [bis(trifluoroacetoxy)iodo]arenes (eqs 6 and 7).7 The reaction of ITT with a variety of aromatic compounds, including those substituted with electron-withdrawing groups, can be employed in a general method for the synthesis of iodoarenes.8 For example, treatment of p-methoxyacetophenone with ITT at rt followed by reduction of the intermediate IIII species with aqueous Sodium Iodide provides the aryl iodide in excellent yield (eq 8).8
Similarly, toluene yields a 2:3 o:p ratio and chlorobenzene yields a 6:94 o:p ratio of products.
[Bis(trifluoroacetoxy)iodo]arenes can be used for the preparation of iodonium salts (eq 9).9
Alkenes yield vic-cis-bis(trifluoroacetoxy) diesters upon addition of ITT (eq 10).10
1,2-Migration occurs in the reaction of Ar2C=CH2 with ITT following addition of water (eq 11).11
Ethers react with ITT to yield a,b-(trifluoroacetoxy) diesters (eqs 12 and 13).5,12,13
Robert M. Moriarty & Jerome W. Kosmeder II
University of Illinois at Chicago, IL, USA