(Bis(trifluoroacetoxy)iodo)benzene

(Bis(trifluoroacetoxy)iodo)­benzene

Names
Preferred IUPAC name Phenyl-λ3-iodanediyl bis(trifluoroacetate)
Other names Phenyliodine bis(trifluoroacetate); PIFA
Identifiers
CAS Number	2712-78-9  N
3D model (JSmol)	Interactive image
ChemSpider	92428  Y
ECHA InfoCard	100.018.462
EC Number	220-308-0
PubChem CID	102317
UNII	659SFV27XS
CompTox Dashboard (EPA)	DTXSID40181584
InChI InChI=1S/C10H5F6IO4/c11-9(12,13)7(18)20-17(6-4-2-1-3-5-6)21-8(19)10(14,15)16/h1-5H Y Key: PEZNEXFPRSOYPL-UHFFFAOYSA-N Y InChI=1/C10H5F6IO4/c11-9(12,13)7(18)20-17(6-4-2-1-3-5-6)21-8(19)10(14,15)16/h1-5H Key: PEZNEXFPRSOYPL-UHFFFAOYAA
SMILES FC(F)(F)C(=O)OI(OC(=O)C(F)(F)F)c1ccccc1
Properties
Chemical formula	C10H5F6IO4
Molar mass	430.041 g·mol−1
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N  verify  (what is  YN ?) Infobox references

(Bis(trifluoroacetoxy)iodo)benzene, C
_⁶H
_⁵I(OCOCF
_³)
_², is a hypervalent iodine compound used as a reagent in organic chemistry. It can be used to carry out the Hofmann rearrangement under acidic conditions. ^[1]

Preparation

The syntheses of all aryl hypervalent iodine compounds start from iodobenzene. The compound can be prepared by reaction of iodobenzene with a mixture of trifluoroperacetic acid and trifluoroacetic acid in a method analogous to the synthesis of (diacetoxyiodo)benzene: ^[1]

It can also be prepared by dissolving diacetoxyiodobenzene (a commercially available compound) with heating in trifluoroacetic acid: ^[2]

Uses

It also brings around the conversion of a hydrazone to a diazo compound, for example in the diazo-thioketone coupling. It also converts thioacetals to their parent carbonyl compounds.

Hofmann rearrangement

The Hofmann rearrangement is a decarbonylation reaction whereby an amide is converted to an amine by way of an isocyanate intermediate. It is usually carried out under strongly basic conditions. ^{[3] [4]}

The reaction can also be carried out under mildly acidic conditions by way of the same intermediate using a hypervalent iodine compound in aqueous solution. ^[1] An example published in Organic Syntheses is the conversion of cyclobutanecarboxamide, easily synthesized from cyclobutylcarboxylic acid, to cyclobutylamine. ^[2] The primary amine is initially present as its trifluoroacetate salt, which can be converted to the hydrochloride salt to facilitate product purification. ^{[1] [2]}

References

1. Aubé, Jeffrey; Fehl, Charlie; Liu, Ruzhang; McLeod, Michael C.; Motiwala, Hashim F. (1993). "6.15 Hofmann, Curtius, Schmidt, Lossen, and Related Reactions". Heteroatom Manipulations. Comprehensive Organic Synthesis II. Vol. 6. pp. 598–635. doi:10.1016/B978-0-08-097742-3.00623-6. ISBN   9780080977430.
2. Almond, M. R.; Stimmel, J. B.; Thompson, E. A.; Loudon, G. M. (1988). "Hofmann Rearrangement Under Mildly Acidic Conditions Using [I,I-Bis(Trifluoroacetoxy)]Iodobenzene: Cyclobutylamine Hydrochloride from Cyclobutanecarboxamide". Organic Syntheses . 66: 132. doi:10.15227/orgsyn.066.0132 ; Collected Volumes, vol. 8, p. 132.
3. Wallis, Everett S.; Lane, John F. (1946). "The Hofmann Reaction". Organic Reactions . 3 (7): 267–306. doi:10.1002/0471264180.or003.07.
4. Surrey, Alexander R. (1961). "Hofmann Reaction". Name Reactions in Organic Chemistry (2nd ed.). Academic Press. pp. 134–136. ISBN   9781483258683.