Phenyliodine diacetate—Iodine

Environmentally benign oxidation of sulfides to sulfoxides was reported by Kita and co-workers by using iodine(III) reagents such as iodosobenzene (PhIO) or phenyliodine diacetate (PIDA) with KBr in water. 

The oxidative fluorination of 4-alkylphenols to give the 4-fluoro-4-alkylcyclohexa-2,5-dien-l-ones can be achieved by using hypervalent iodine reagents, such as phenyliodo bis(trifluoroacetate) or phenyliodine diacetate in the presence of pyridinium polyhydrogen fluoride (equation 81) vide infra). ... 

Takeda et al. applied a hypervalent iodine(III)-initiated oxidative [4 + 2] cyclization of o-phenylenediamines and electron-poor alkynes to the preparation of quinoxalines 125 from alkyne starting materials without the presence of metal catalysts (Scheme 52) (13CC9266). Optimal reaction conditions were found to be phenyliodine diacetate (PIDA) (2 equiv) as the... 

Epimines. Irradiation of nitroamines and cyanoamines in the presence of phenyliodine(III) diacetate and iodine generates an aminyl radical which undergoes intramolecular hydrogen abstraction to produce epimines. 

Iodine-Mercury(II) oxide, 149 Lithium diisopropylamide-Potassium /-butoxide, 164 Molybdenum carbonyl, 194 Phenyliodine(III) diacetate, 242 Sulfuryl chloride, 284 Conjugate addition reactions Michael reactions Alumina, 14... 

In particular, (diacyloxyiodo)benzene such as phenyliodine(III) diacetate (PIDA) and phenyliodine(III) bis(trifluoroacetate) (PIFA) have received a great deal of attention due to their reactivities similar to those of heavy metal reagents or anodic oxidation, low toxicity, ready availability and easy handling. Accordingly, a variety of useful oxidation reactions using iodine(III) or iodine(V) reagents have been developed recently. A number of previous review articles and... 

More recently, a new class of non-metallic oxidation reagents has been reported - the hy-pervalent iodine complexes [19]. Phenyliodine(III) diacetate (PIDA) and phenyliodine(III) bis(trifluoroacetate) (PIFA) have proven to be very efficient reagents that give rise to higher regioselectivity than other oxidants in some reactions and, more importantly, offer a mild and non-toxic alternative to the heavy metals. 

Phenyliodine(III) diacetate-M lodination. An acid-cai combination. An oxidatise d<5 introduction of an iodine atom 1... 

Yeung and coworkers oxidize the allylic position of alkenes using a combination of phenyliodine(III) diacetate and t-butyl hydroperoxide in an ester solvent. A variety of substituted cyclic alkenes, including steroid frameworks, can be oxidized to a,P-unsaturated ketones. Ester solvents proved crucial for the success of the reaction, leading to the supposition that coordination of the carbonyl of the ester to the iodine center is necessary for the reaction to proceed. 

Zhu and coworkers developed the cyclization of Al-arylamidines 55 and 56 mediated by phenyliodine(III) diacetate. Ligand substitution of the amidine for the acetate on the iodine center generates an Af-iodoimido intermediate. Homolysis gives an IV-centered radical which can undergo HAS. Formation of the N—C bond provides a resonance-stabilized radical. The iodine species accepts a second electron to form a cationic intermediate similar to EAS. Final rearomatization by deprotonation provides the benzimidazoles 57 and 58. 

The Yokoyama group found that irradiating 3-phenyl-l-propanol and its derivatives 59 and 60 with phenyliodine(III) diacetate and I2 formed a hypoiodite. Homolytic O—I bond cleavage results in an oxygen-centered radical which can undergo HAS to synthesize a chromane. Once formed, however, the now-activated electron-rich aromatic ring is primed for a classical EAS under tlie reaction conditions. AcOI acts as the electrophile for this tandem reaction to place an iodine substituent para to the new oxygen substituent in products 61 and 62. ... 

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