Chemicals >> Oxidizing Agents >> Hypervalent Iodine Compounds

Iodosobenzene Diacetate, Phenyliodonium Diacetate, PIDA

Recent Literature

LiBr is an efficient catalyst for the dihydroxylation of alkenes to afford either syn or anti diols with excellent diastereoselectivity depending upon the use of NaIO₄ or PhI(OAc)₂ as the oxidants.
L. Emmanuvel, T. M. A. Shaikh, A. Sudalai, Org. Lett., 2005, 7, 5071-5074.

Selective syn and anti diacetoxylations of alkenes have been achieved using a PhI(OAc)₂/BF₃·OEt₂ system in the presence and absence of water, respectively. A broad range of substrates including electron-deficient alkenes furnishes the desired products in good to excellent yields and diastereoselectivity. This novel methodology provides an alternative approach for the preparation of various 1,2-diols.
W. Zhong, J. Yang, X. Meng, Z. Li, J. Org. Chem., 2011, 76, 9997-10004.

W. Zhong, J. Yang, X. Meng, Z. Li, J. Org. Chem., 2011, 76, 9997-10004.

Copper(I) or -(II) salts with weakly coordinating anions catalyze a mild diacetoxylation of olefins efficiently in the presence of PhI(OAc)₂ as the oxidant. The reaction is effective for aryl, aryl alkyl, as well as aliphatic terminal and olefins forming the corresponding vicinal diacetoxy compounds in good yields. Internal olefins lead to syn/anti mixtures of up to 5.2.
J. Seayad, A. M. Seayad, C. L. L. Chai, Org. Lett., 2010, 12, 1412-1415.

In a rhenium-catalyzed oxyalkylation of alkenes, hypervalent iodine(III) reagents derived from widely occurring aliphatic carboxylic acids were not only an oxygenation source but also an alkylation source via decarboxylation. The reaction offers a wide substrate scope, totally regiospecific difunctionalization, mild reaction conditions, and ready availability of both substrates.
Y. Wang, L. Zhang, Y. Yang, P. Zhang, Z. Du, C. Wang, J. Am. Chem. Soc., 2013, 135, 18048-18051.

Half-sandwich ruthenium complexes activate terminal alkynes toward anti-Markovnikov hydration and reductive hydration under mild conditions. Propargylic alcohols can be converted to 1,3-diols in high yield and with retention of stereochemistry at the propargylic position. The method is also amenable to formal anti-Markovnikov reductive amination and oxidative hydration reactions to access linear amines and carboxylic acids, respectively.
M. Zeng, S. B. Herzon, J. Org. Chem., 2015, 80, 8604-8618.

An oxidative decarboxylation of β,γ-unsaturated carboxylic acids mediated by PhI(OAc)₂ gives the corresponding allylic acetates. In addition, a decarboxylative C-N bond formation was achieved. Mechanistic studies suggest an unique reactivity of hypervalent iodine reagents in this ionic oxidative decarboxylation.
K. Kiyokawa, S. Yahata, T. Kojima, S. Minakata, Org. Lett., 2014, 16, 4646-4649.

The hypervalent iodine reagent PIDA in combination with a nucleophilic amine (DABCO or pyridine) induces α-functionalization of enones via umpolung of Morita-Baylis-Hillman type intermediates. Depending on the presence of additional nucleophiles, α-chloro-enones, 1,2-diketones and α-tosyloxy-enones can be obtained.
S. Arava, S. K. Santra, G. K. Pathe, R. Kapanaiah, A. M. Szpilman, Angew. Chem. Int. Ed., 2000, 59, 15171-15175.

The use of PhI(OAc)₂ in dichloromethane enables a clean oxidative cleavage of 1,2-diols to aldehydes. In the presence of OsO₄ as catalyst, NMO and 2,6-lutidine, olefinic bonds can be cleaved in acetone/water to yield the corresponding carbonyl compounds.
K. C. Nicolaou, V. A. Adsool, C. R. H. Hale, Org. Lett., 2010, 12, 1552-1555.

K. C. Nicolaou, V. A. Adsool, C. R. H. Hale, Org. Lett., 2010, 12, 1552-1555.

An I(III)-mediated skeletal reorganization of silyl enol ethers enables a formal enone α-arylation. This metal-free transformation offeres mild conditions, good yields, and high stereoselectivities for β-substituted enones.
B. S. Martins, D. Kaiser, A. Bauer, I. Tiefenbrunner, N. Maulide, Org. Lett., 2021, 23, 2094-2098.

A boryl-directed intermolecular C-H amination of allyl N-methyliminodiacetyl boronates (B(MIDA)s) and propargylic B(MIDA)s provide α-amino boronates with an exceptionally high level of site-selectivity. A wide variety of highly functionalized secondary and tertiary α-amino boronates are formed in very good yields under mild reaction conditions.
Y. Liu, Z.-H. Chen, Y. Li, J. Qian, Q. Li, H. Wang, J. Am. Chem. Soc., 2022, 144, 14380-14387.

Copper catalyzes a mild acetalization of boronic esters in the presence of a variety of functional groups. This Chan-Lam coupling method enables an orthogonal acetalization of substrates with reactive, acid-sensitive functional groups.
E. M. Miller, M. A. Walczak, J. Org. Chem., 2020, 85, 8230-8239.

Hypervalent Iodine(III)-Mediated Decarboxylative Ritter-Type Amination Leading to the Production of α-Tertiary Amine Derivatives
K. Kiyokawa, T. Watanabe, L. Fra, T. Kojima, S. Minakata, J. Org. Chem., 2017, 82, 11711-11720.

The combination of PhI(OAc)₂ and Cs₂CO₃ mediates an efficient oxidative 1,2-C to N migration of primary amines. The reaction can be applied to the preparation of both acyclic and cyclic amines. A mechanistic study shows that the rearrangement proceeds via a concerted mechanism.
W. Yamakoshi, M. Arisawa, K. Murai, Org. Lett., 2019, 21, 3023-3027.

A metal-free allylic amination of alkenes with simple sulfonamides and sulfamates allows the introduction of a wide range of nitrogen functionality at the allylic position of alkenes with unique regioselectivity and no allylic transposition in the presence of phosphine selenides or selenoureas as catalysts.
W. P. Teh, D. C. Obenschain, B. M. Black, F. E. Michael, J. Am. Chem. Soc., 2020, 142, 16716-16722.

A direct conversion of a wide range of aliphatic, benzylic, heteroaromatic, allylic, and propargyl alcohols into nitriles with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), iodosobenzene diacetate, and ammonium acetate as a nitrogen source proceeds through an oxidation-imination-aldimine oxidation sequence in situ. Highly chemoselective ammoxidation of primary alcohols in the presence of secondary alcohols was also achieved.
J.-M. Vatèle, Synlett, 2014, 25, 1275-1278.

A highly atom-economical strategy for a copper-catalyzed synthesis of chiral propargylic cyanides is based on a direct decarboxylation of propargylic carboxylic acids without preactivation. The reactions show excellent selectivity and functional group compatibility. Gram-scale reaction and several conversion reactions from chiral propargylic cyanide have demonstrated the synthetic value of this strategy.
G. Zhang, Y. Pei, J. Wang, X. Zhu, Z. Li, F. Zhao, F. Zhao, J. Wu, Org. Lett., 2023, 25, 5006-5010.

The use of diacetoxyiodobenzene in the presence of an ionic liquid enables a facile one-pot synthesis of a series of amides from aldehydes and amines at ambient temperature.
V. Prasad, R. R. Kale, B. B. Mishra, D. Kumar, V. K. Tiwari, Org. Lett., 2012, 14, 2936-2939.

A combination of PhI(OAc)₂ and BF₃·Et₂O promoted the Beckmann rearrangement of ketoximes to provide amides. The Beckmann rearrangement is preceded by acetylation of the hydroxy group of the ketoxime in situ, accelerating the Beckmann rearrangement. The reaction of ketoximes with Koser's reagent in the presence of THF provides ketones in high yields at room temperature.
T. Maegawa, R. Oishi, A. Maekawa, K. Segi, H. Hamamoto, A. Nakamura, Y. Miki, Synthesis, 2022, 54, 4095-4103.

A metal-free oxidative-amidation strategy enables the synthesis of α-ketothioamides and amides from α-azido ketones. The C-H bond thionation of α-azido ketones with elemental sulfur could form α-ketothioacyl azide, which was then nucleophilically attacked by amines, while amides could be formed with the release of nitrogen gas and cyano anion in the presence of PhI(OAc)₂.
P. Yu, Y. Wang, Z. Zeng, Y. Chen, J. Org. Chem., 2019, 84, 14883-14891.

A direct and convenient reaction of primary amides with phenyliodine diacetate in the presence of an ammonia source (NH₃ or ammonium carbamate) provides N-substituted ureas. This transformation involves a nucleophilic addition of ammonia to an isocyanate intermediate generated in situ by a Hofmann rearrangement of the starting amide.
N. S. Rosa, T. Glachet, Q. Ibert, J.-F. Lohier, X. Franck, V. Reboul, Synthesis, 2020, 52, 2099-2105.

Visible light mediates a convenient oxidative cross-coupling of arylglyoxylic acids with tetraalkylthiuram disulfides to provide α-ketoamides in good yields under ambient air at room temperature via a radical pathway.
S. Sarkar, S. Pal, A. Mukherjee, S. Santra, G. V. Zyryanov, A. Majee, J. Org. Chem., 2024, 89, 1473-1482.

A copper-catalyzed cross-dehydrogenative coupling reaction between N-hydroxyphthalimide and aldehydes using PhI(OAc)₂ as an oxidant enables a synthesis of NHPI esters in good yields in water. This facile and efficient method is eco-friendly and offers mild conditions, short reaction time, and broad substrate scope.
Z. Guo, X. Jiang, C. Jin, J. Zhou, B. Sun, W. Su, Synlett, 2017, 28, 1321-1326.

A hypervalent iodine reagent, (diacetoxyiodo)benzene, and catalytic amount of sodium azide in acetonitrile enable an oxidative decarboxylation of 2-aryl carboxylic acids into the corresponding aldehydes, ketones, and nitriles in good yields at room temperature. The advantages of this protocol are short reaction times and mild reaction conditions.
V. N. Telvekar, K. A. Sasane, Synlett, 2010, 2778-2779.

The use of PhI(OAc)₂ enables an efficient access to α,α′-diacetoxy ketones has from ethynylcarbinols. Glycerol derivatives can be easily synthesized in good yields via a one-pot reaction. A plausible mechanism is proposed.
Q.-R. Liu, C.-X. Pan, X.-P. Ma, D.-L. Mo, G.-F. Su, J. Org. Chem., 2015, 80, 6496-6501.

Phenyliodonium diacetate mediates a synthesis of α-oxygenated ketones from styrenes in the presence of molecular oxygen and N-hydroxyphthalimide or N-hydroxybenzotriazole under metal-free conditions. The present method is applicable for wide range of styrenes with various functional groups.
S. Samanta, R. R. Donthiri, C. Ravi, S. Adimurthy, J. Org. Chem., 2016, 81, 3457-3463.

Pd-catalyzed selective oxidation of Boc-protected N-methylamines with IOAc as the oxidant involves a Boc-directed C-H activation process.
D.-H. Wang, X.-S. Hao, D.-F. Wu, J.-Q. Yu, Org. Lett., 2006, 8, 3387-3390.

A one-pot two-step sequence involving an oxidation/imine-iminium formation/reduction allowed the N-alkylation of amines by alcohols. Optically active alcohols and amines can be converted without any epimerization.
C. Guérin, V. Bellosta, G. Guillamot, J. Cossy, Org. Lett., 2011, 13, 3478-3481.

An oxidation/imine-iminium formation/reduction cascade using TEMPO-BAIB-HEH-Brønsted acid catalysis in DMPU as solvent enables a mild and atom-economical nonepimerizing chemo- and enantioselective N-alkylating procedure of amines with alcohols.
I. A. Khan, A. K. Saxena, J. Org. Chem., 2013, 78, 11656-11669.

Alkynyl hydrazones can be conveniently synthesized from 2-oxo-3-butynoates and hydrazine without formation of pyrazoles. The resultant hydrazones are transformed into alkynyl diazoacetates under mild oxidative conditions in excellent yields. Further, alkynyl cyclopropane and propargyl silane carboxylates are synthesized in good yields using copper-catalyzed alkynyl carbene transfer reactions.
A. Sharma, P. Jamwal, H. Vaid, R. Gurubrahamam, Org. Lett., 2023, 25, 1889-1894.

Trimethylchlorosilane was used as chlorine source for the α-chlorination of 1,3-dicarbonyl compounds with phenyliodonium diacetate as oxidant at room temperature to provide α-monochlorinated products in good yield. TMSBr could be used to form monobromide products.
S. Chong, Y. Su, L. Wu, W. Zhang, J. Ma, X. Chen, D. Huang, K.-H. Wang, Y. Hu, Synthesis, 2016, 48, 1359-1370.

A mild and rapid formal electrophilic α-azidation of 1,3-dicarbonyl compounds using commercially available Bu₄NN₃ as the azide source is mediated by (diacetoxyiodo)benzene. The reaction conditions are Bäcklund to the ones employed in analogous halogenations with Et₄NX (X = Cl, Br, I).
M. J. Galligan, R. Akula, H. Ibrahim, Org. Lett., 2014, 16, 600-603.

M. J. Galligan, R. Akula, H. Ibrahim, Org. Lett., 2014, 16, 600-603.

A tandem metal-free oxidative aryl migration/C-C bond-cleavage reaction, mediated by hypervalent iodine reagent, provides straightforward access to important α-ketoamide and α-ketoester derivatives from readily available acrylic derivatives via a concerted process of 1,2-aryl shift concomitant with C-C bond cleavage.
L. Liu, L. Du, D. Zhang-Negrerie, Y. Du, K. Zhao, Org. Lett., 2014, 16, 5772-5775.

A metal-free PhI(OAc)₂ mediated nitrogenation of alkenes via C=C bond cleavage using inorganic ammonia salt as nitrogen source under mild conditions affords nitriles in good yields. The method offers mild reaction conditions, operational simplicity, and use of an ammonium salt as nitrogen source. A plausible reaction mechanism is proposed.
J.-H. Xu, Q. Jiang, C.-C. Guo, J. Org. Chem., 2013, 78, 11881-11882.

The combination of hypervalent iodine(III) and TMSN₃ promotes an oxidative cleavage of C-C double bonds of enamides under an air atmosphere. This method exhibits good functional group tolerance, broad substrate scope and mild conditions. The reaction also offers an approach to cyanobenzamides with synthetic potential for the preparation of industrial and pharmaceutical nitrogen- and oxygen-containing molecules.
G. Liu, Y. Li, J. Sheng, X.-S. Wang, Synthesis, 2017, 49, 3968-3974.

Gold-catalyzed oxidative cross-coupling of alkynes to unsymmetrical diynes has been achieved in the presence of 1,10-Phen as ligand and PhI(OAc)₂ as oxidant giving the desired cross-coupled conjugated diynes in excellent heteroselectivity (>10:1), in good to excellent yields, and with large substrate tolerability.
H. Peng, Y. Xi, N. Ronaghi, B. Dong, N. G. Akhmedov, X. Shi, J. Am. Chem. Soc., 2014, 136, 13174-13177.

Low loadings of imidazol(in)ium aurates catalyze a simple and efficient oxidative coupling of terminal alkynes. This approach displays high functional group tolerance and leads to a broad range of 1,3-diyne compounds in good yields in air under mild and sustainable conditions.
X. Ma, N. V. Tzouras, M. Peng, K. Van Hecke, S. P. Nolan, J. Org. Chem., 2022, 87, 4883-4893.

In a palladium-catalyzed intermolecular aminocarbonylation of alkenes, the use of hypervalent iodine reagent can accelerate the reaction. The current transformation presents a convenient method to generate β-amino acid derivatives from simple alkenes.
J. Cheng, X. Qi, M. Li, P. Chen, G. Liu, J. Am. Chem. Soc., 2015, 137, 2480-2483.

A cobalt-catalyzed decarboxylative acetoxylation reaction is applicable to a wide range of amino acids and arylacetic acids.
K. Xu, Z. Wang, J. Zhang, L. Yu, J. Tan, Org. Lett., 2015, 17, 4476-4478.

A reaction between terminal alkynes and sulfonamides under ambient air using PIDA (diacetoxy iodobenzene) provides α-sulfonylamino ketones. This metal-free reaction offers a broad substrate scope, excellent regioselectivity, easily accessible reactants, and mild reaction conditions and is operationally simple.
S. Mahato, S. Santra, G. V. Zyryanov, A. Majee, J. Org. Chem., 2019, 84, 3176-3183.

In a radical-mediated strategy for β C-H amination of alcohols, imidates as radical relay chaperones serve as traceless directors that facilitates selective C-H functionalization via 1,5-hydrogen atom transfer (HAT) and enable net incorporation of ammonia at the β carbon. A streamlined protocol enables rapid conversion of alcohols to their β-amino analogs (via in situ conversion of alcohols to imidates, directed C-H amination, and hydrolysis).
E. A. Wappes, K. M. Nakafuku, D. A. Nagib, J. Am. Chem. Soc., 2017, 139, 10204-10207.

Intramolecular C-H amination using commercial Rh-catalysts, PhI(OAc)₂, and MgO offers a practical solution for the controlled oxidation of saturated C-H bonds. Reactions of sulfamates with 2 mol % Rh₂(OAc)₄, PhI(OAc)₂, and MgO yield selectively six-membered ring oxathiazinanes. These heterocycles can serve as precursors for 1,3-amino alcohols, β-amino acids, and numerous other amine derivatives.
C. G. Espino, P. M. Wehn, J. Chow, J. Du Bois, J. Am. Chem. Soc., 2001, 123, 6935-6936.

The reaction of a N-silyl sulfinylamine reagent with Grignard, organolithium, or organozinc reagents provides a broad range of (hetero)aryl, alkenyl, and alkyl primary sulfinamides. Treatment of these primary sulfinamides with an amine in the presence of a hypervalent iodine reagent leads directly to sulfonimidamides.
M. Ding, Z.-X. Zhang, T. Q. Davies, M. C. Willis, Org. Lett., 2022, 24, 1711-1715.

Phenyliodonium diacetate mediates an efficient oxidative esterification of sulfenamides to provide sulfinimidate esters and sulfilimines under mild and metal-free conditions in very good yields. The protocol is readily scalable and compatible with a diverse range of substrates and functional groups.
X. Lu, G. Huang, J. Ye, M. A. Bashir, J. Su, K. Yang, F. Liang, X. Xu, Org. Lett., 2023, 25, 2151-2156.

The use of phenyliodonium diacetate (PIDA) and ammonia enables a one-pot metal-free conversion of unprotected amino acids to terminal diazirines. This method tolerates a broad range of functional groups, is operationally simple, and can be scaled up to provide multigram quantities of diazirine.
T. Glachet, H. Marzag, N. S. Rosa, J. F. P. Colell, G. Zhang, W. S. Warren, X. Franck, T. Theis, V. Reboul, J. Am. Chem. Soc., 2019, 141, 13689-13696.

An iron-catalyzed C(sp³)-H acyloxylation of aryl-2H azirines with hypervalent iodine(III) reagents (HIRs) provides a wide range of monoacyloxylated 3-aryl-2H-azirines in good yields.
L. Wang, H. Li, L. Wang, Org. Lett., 2018, 20, 1663-1666.

A visible-light-promoted regioselective coupling of aryl-2H-azirines and (diacetoxy)iodobenzene provides C(sp³)-H acyloxylated azirines in the presence of Rose Bengal as an organophotoredox catalyst. The reaction proceeds under aerobic condition at room temperature via a radical pathway.
A. De, S. Santra, A. Hajra, G. V. Zyrayanov, A. Majee, J. Org. Chem., 2019, 84, 11735-11740.

A Pd-catalyzed, asymmetric 6-endo aminoacetoxylation of unactivated alkenes provides chiral β-acetoxylated piperidines with excellent chemo-, regio- and enantioselectivities under very mild reaction conditions using a designed pyridine-oxazoline (Pyox) ligand.
X. Qi, C. Chen, C. Hou, L. Fu, P. Chen, G. Liu, J. Am. Chem. Soc., 2018, 140, 7415-7419.

Copper(II) trifluoromethanesulfonate catalyzed a mild amidation of cyclic ethers with iminoiodanes with good yields and selectivity. A subsequent reductive ring-opening of the tosylamidated products gives α,ϖ-amino alcohols.
L. He, J. Yu, J. Zhang, X.-Q. Yu, Org. Lett., 2007, 9, 2277-2280.

A 5-endo trig oxidative radical cyclization of benzylamine-derived Ugi three-component reaction products rapidly affords imidazolidinones. This oxidative radical cyclization generates highly decorated privileged heterocycles.
K. Schofield, C. Foley, C. Hulme, Org. Lett., 2021, 23, 107-112.

An oxidative cyclization of β-substituted β,γ-unsaturated carboxylic acids using a hypervalent iodine reagent provides 4-substituted furan-2-ones. The use of the highly electrophilic PhI(OTf)₂, which is in situ prepared from PhI(OAc)₂ and Me₃SiOTf, is crucial. Depending on the substitution pattern at the α-position of the substrates, furan-2(5H)-ones or furan-2(3H)-ones are produced.
K. Kiyokawa, K. Takemoto, S. Yahata, T. Kojima, S. Minakata, Synthesis, 2017, 49, 2907-2912.

In the presence of 1.1 equiv of (Diacetoxyiodo)benzene (PIDA) and suitable halogen sources, a variety of olefins underwent haloamidation, haloetherification, and halolactonization to the corresponding 1,2-bifunctional cyclic skeletons in very good isolated yields. Subsequent mild nucleophilic substitution gives key intermediates for biologically interesting compounds in high yields.
G.-Q. Liu, Y.-M. Li, J. Org. Chem., 2014, 79, 10094-10109.

G.-Q. Liu, Y.-M. Li, J. Org. Chem., 2014, 79, 10094-10109.

The oxyindation of carbonyl-ene-yne compounds with indium trihalides provides di-, tri-, and tetrasubstituted 2-pyrones bearing a carbon-indium bond. The metalated 2-pyrones can be oxidized or cross-coupled to multifunctionalized 2-pyrones.
T. Yata, Y. Kita, Y. Nishimoto, M. Yasuda, J. Org. Chem., 2019, 84, 14330-14341.

An efficient synthesis of indoline compounds from picolinamide (PA)-protected β-arylethylamine substrates via palladium-catalyzed intramolecular amination of ortho-C(sp²)-H bonds features high efficiency, low catalyst loadings, mild operating conditions, and the use of inexpensive reagents.
G. He, C. Lu, Y. Zhao, W. A. Nack, G. Chen, Org. Lett., 2012, 14, 2936-2939.

A Pd(II)-catalyzed intramolecular C-H amination of 2-pyridinesulfonyl-protected phenethylamine derivatives using PhI(OAc)₂ as a bystanding oxidant provides access to various substituted indoline derivatives in good yields. The use of the 2-pyridinesulfonyl protecting group enables a facile deprotection following C-H functionalization.
T.-S. Mei, D. Leow, H. Xiao, B. N. Laforteza, J.-Q. Yu, Org. Lett., 2013, 15, 3058-3061.

Treatment of 2-alkenylanilines with phenyliodine(III) diacetate (PIDA) and LiBr or KI in HFIP provides the corresponding 3-bromoindoles and 3-iodoindoles via cascade oxidative cyclization/halogenation.
B. Zhao, X. Li, X. Wang, L. Jiang, Z. Li, Y. Du, J. Org. Chem., 2023, 88, 1493-1503.

3-Monofunctionalized 2-oxindoles were conveniently synthesized from reactions between an anilide and phenyliodine(III) diacetate (PIDA) through hypervalent iodine mediated C(sp²)–C(sp²) bond formation followed by a subsequent deacylation. This metal-free method provides direct access to interesting oxindole intermediates, as exemplified by the total synthesis of horsfiline.
J. Lv, D. Zhang-Negrerie, J. Deng, Y. Du, K. Zhao, J. Org. Chem., 2014, 79, 1111-1119.

2-Benzyl-N-tosylbenzamides and related substrates undergo copper-catalyzed intramolecular benzylic sulfamidation to provide N-arylsuflonyl-1-arylisoindolinones.
R. B. Bedford, J. G. Bowen, C. Méndez-Gálvez, J. Org. Chem., 2017, 82, 1719-1725.

The use of Cu(OAc)₂ as the catalyst in the presence of PhI(OAc)₂ and K₃PO₄ enables an amination of aliphatic C-H bonds of N-alkylamidines to yield dihydroimidazoles and tetrahydropyrimidines. A subsequent hydride reduction gives the corresponding diamines.
H. Chen, S. Synjaya, Y.-F. Wang, S. Chiba, Org. Lett., 2013, 15, 212-215.

A metal-free catalytic strategy for the facile synthesis of biologically relevant indolizines and imidazopyridines is promoted by amine and N-heterocyclic carbene (NHC) relay catalysis via Michael addition-[3 + 2] fusion of simple azaarenes and α,β-unsaturated aldehydes.
H. Li, X. Li, Y. Yu, J. Li, Y. Liu, H. Li, W. Wang, Org. Lett., 2017, 19, 2010-2013.

A new palladium-catalyzed method allows the oxygenation of unactivated sp³ C-H bonds of a wide variety of alkane substrates containing readily available oxime and/or pyridine directing groups with extremely high levels of chemo-, regio-, and in some cases diastereoselectivity.
L. V. Desai, K. L . Hull, M. S. Sanford, J. Am. Chem. Soc., 2004, 126, 9542-9543.

Palladium-catalyzed intramolecular amination of unactivated C-H bonds at the γ and δ positions of picolinamide (PA) protected amine substrates enables the synthesis of azetidine, pyrrolidine, and indoline compounds. The method features relatively low catalyst loading, use of inexpensive reagents, convenient operating conditions and predictable selectivities.
G. He, Y. Zhao, S. Zhang, C. Lu, G. Chen, J. Am. Chem. Soc., 2012, 134, 3-6.

A palladium-catalyzed intramolecular diamination reaction yields cyclic ureas as direct products of an oxidative alkene transformation in the presence of iodosobenzene diacetate as terminal oxidant.
J. Streuff, C. H. Hövelmann, M. Nieger, K. Muniz, J. Am. Chem. Soc., 2005, 127, 14586-14587.

An intermolecular Pd-catalyzed aminoacetoxylation of alkenes with phthalimide as the nitrogen source and PhI(OAc)₂ as the stoichiometric oxidant and source of acetate achieves a highly regio- and diastereoselective oxidative 1,2-difunctionalization of alkenes. The mechanism is discussed.
G. Liu, S. S. Stahl, J. Am. Chem. Soc., 2006, 128, 7179-7181.

A catalytic Mitsunobu reaction system is described in which the azo reagent is used as an organocatalyst and iodosobenzene diacetate is used as the stoichiometric oxidant. Yields obtained in the catalytic reactions of carboxylic acids and alcohols were slightly lower than those obtained from corresponding stoichiometric reactions.
T. Y. S. But, P. H. Toy, J. Am. Chem. Soc., 2006, 128, 9636-9637.

A gold(I) compound, supported by 4,4',4' '-tri-tert-butyl-2,2':6',2' '-terpyridine (tBu₃tpy) as the ligand, efficiently catalyzes olefin aziridination with the use of the commercially available oxidant PhI(OAc)₂ and sulfonamides.
Z. Li, X. Ding, C. He, J. Org. Chem., 2006, 71, 5876-5880.

The combination of I₂/PhI(OAc)₂ promotes an efficient and practical one-pot reaction of amines with alkyne esters and chalcones under solvent-free ball-milling conditions to afford a variety of polysubstituted trans-2,3-dihydropyrroles in good yields. This protocol furnishes the corresponding pyrroles with the addition of DDQ as oxidant in a subsequent step.
H. Xu, H.-W. Liu, K. Chen, G.-W. Wang, J. Org. Chem., 2018, 83, 6035-6049.

A broad range of functionalized oxazoles were synthesized in good yields from enamides via phenyliodine diacetate (PIDA)-mediated intramolecular cyclization. The oxidative carbon-oxygen bond formation process is heavy-metal-free.
Y. Zheng, X. Li, C. Ren, D. Zhang-Negrerie, Y. Du, K. Zhao, J. Org. Chem., 2012, 77, 10353-10361.

Hypervalent iodine compounds enable Pd-catalyzed acetoxylative, alkoxylative, and hydroxylative cycloisomerizations of homoallenyl amides to give three different types of polysubstituted 2-aminofurans in promising yields at room temperature.
C. Cheng, S. Liu, G. Zhu, J. Org. Chem., 2015, 80, 7604-7612.

Various primary alcohols were smoothly transformed into 3-substitued isoxazoles in good yields in one pot by successive treatment with PhI(OAc)₂ in the presence of TEMPO, NH₂OH, and then NCS, followed by reaction with alkynes in the presence of Et₃N. The use of PhNHNH₂ instead of NH₂OH and decyl methyl sulfide as additive in a later step enabled the synthesis of pyrazoles.
E. Kobayashi, H. Togo, Synthesis, 2019, 51, 3723-3735.

N-Alkyl enamines can be transformed into highly subsituted imidazoles in the presence of (diacetoxyiodo)benzene and TMSN₃ under catalysis of a copper salt such as Cu(OAc)₂ via a domino azidation/intramolecular C(sp³)-H amination. The present reaction provides an efficient method for the preparation of 4-(trifluoromethyl) imidazoles.
H. Ma, X. Zhang, L. Chen, W. Yu, J. Org. Chem., 2017, 82, 11841-11847.

Various 2-arylbenzimidazoles were synthesized from phenylenediamines and aldehydes via a one-step process using hypervalent iodine as oxidant. This method features mild conditions, short reaction times, high yields, and a simple procedure.
L-H. Du, Y.-G. Wang, Synthesis, 2007, 675-678.

A convenient metal-free cyclization of ortho-hydroxystilbenes into 2-arylbenzofurans and 2-arylnaphthofurans is mediated by hypervalent iodine reagents. Using stoichiometric (diacetoxyiodo)benzene in acetonitrile, desired products can be isolated in good yields.
F. V. Singh, T. Wirth, Synthesis, 2012, 44, 1171-1177.

Pd(II)-catalyzed C-H activation of phenylacetic acids followed by an intramolecular C-O bond formation afforded benzofuranones. A modified reaction provides the first example of enantioselective C-H functionalizations through Pd(II)/Pd(IV) redox catalysis.
X.-F. Cheng, Y. Li, Y.-M. Su, F. Yin, J.-Y. Wang, J. Sheng, H. U. Vora, X.-S. Wang, J.-Q. Yu, J. Am. Chem. Soc., 2013, 135, 1236-1239.

A fast and simple reaction of amidines gave benzimidazoles via iodine(III)-promoted oxidative C(sp³)-C(sp²) bond formation in nonpolar solvents, whereas the use of polar solvents favoured a C(sp²)-N bond formation to yield quinazolines. Further selective synthesis of quinazolines in polar solvent was realized using TEMPO as catalyst and K₂S₂O₈ as the oxidant. No metal, base, or other additives were needed.
J.-P. Lin, F.-H. Zhang, Y.-Q. Long, Org. Lett., 2014, 16, 2822-2825.

2-Imidazolines were easily prepared in good yields from the reaction of aldehydes and ethylenediamine with iodine in the presence of potassium carbonate. The 2-imidazolines were smoothly oxidized to the corresponding imidazoles in good yields using (diacetoxyiodo)benzene at room temperature.
M. Ishihara, H. Togo, Synlett, 2006, 227-230.

Iodobenzene diacetate efficiently oxidizes aldoximes to nitrile oxides in MeOH containing a catalytic amount of TFA. Nitrile oxides may be trapped in situ with olefins in a bimolecular or an intramolecular mode. Tandem oxidative dearomatization of phenols/intramolecular nitrile oxide cycloaddition sequences lead to useful synthetic intermediates.
B. A. Mendelsohn, S. Lee, S. Kim, F. Tayssier, V. S. Aulakh, M. A. Ciufolini, Org. Lett., 2009, 11, 1539-1542.

Various substituted enamine derivatives can be conveniently converted to the corresponding 2H-azirines mediated by phenyliodine (III) diacetate (PIDA). The formed 2-aryl-2H-azirines allow the synthesis of indole-3-carbonitriles or isoxazoles via thermal rearrangements.
X. Li, Y. Du, Z. Liang, X. Li, Y. Pan, K. Zhao, Org. Lett., 2009, 11, 2643-2646.

A facile one-pot (3 + 2) cycloaddition-isomerization-oxidation sequence employing 2,2,2-trifluorodiazoethane and styryl derivatives provides 5-aryl-3-trifluoromethylpyrazoles in good yields under mild conditions. The reaction tolerates a broad variety of functional groups.
J. Alterejos, E. Merino, D. Sucunza, J. J. Vaquero, J. Carreras, J. Org. Chem., 2023, 88, 11258-11262.

An iodine(III)-catalyzed oxidative cyclization of 2-hydroxystilbenes using 10 mol% (diacetoxyiodo)benzene [PhI(OAc)2] as catalyst in the presence of m-chloroperbenzoic acid provides 2-arylbenzofurans in good to excellent yields.
F. V. Singh, S. R. Mangaonkar, Synthesis, 2018, 50, 4940-4948.

A nickel-catalyzed intramolecular oxidative C-H bond functionalization of arylthioureas provides 2-aminobenzothiazoles in very good yields and short reaction times. This protocol features an inexpensive catalyst, low catalyst loading, mild reaction conditions, and can be scaled up easily to a gram scale.
M.-Y. Gao, J.-H. Li, S.-B. Zhang, L.-J. Chen, Y.-S. Li, Z.-B. Dong, J. Org. Chem., 2020, 85, 493-500.

Visible light mediates an operationally simple and regioselective synthesis of 2-sulfonamidoindoles and other 2-sulfonamido heteroarenes by an oxidative cross-dehydrogenative coupling of indoles (heteroarenes) with di-p-toluenesulfonamide or N-aryl-p-toluenesulfonamides in the presence of eosin-Y. The reaction enables the synthesis of a wide range of amidated heterocyclic compounds.
A. Paul, A. Sengupta, S. Yadav, J. Org. Chem., 2023, 88, 9599-9614.

A tandem oxidative cyclization/1,2-carbon migration of a broad scope of hydrazides enables the synthesis of otherwise inaccessible hindered or enantiopure triazolopyridinones with retention of configuration. This protocol can be easily scaled up by continuous flow synthesis under mild conditions.
Z. Ye, H. Zhang, N. Chen, Y. Wu, F. Zhang, Org. Lett., 2020, 22, 6464-6467.

A Pd(II)-catalyzed C-H bond amination reaction operates under extremely mild conditions and produces carbazole products in good to excellent yields. Carbazoles possessing complex molecular architecture can also be formed using this reaction, highlighting its potential in natural product synthesis applications.
J. A. Jordan-Hore, C. C. C. Johansson, M. Gulias, E. M. Beck, M. J. Gaunt, J. Am. Chem. Soc., 2008, 130, 16184-16186.

A copper-catalyzed cycloamination of α-Csp³-H bond of N-aryl ketimines with sodium azide provides an efficient access to quinoxalines. The reaction features mild conditions and a broad functional group tolerance.
T. Chen, X. Chen, J. Wei, D. Lin, Y. Xie, W. Zeng, Org. Lett., 2016, 18, 2078-2081.

Cyclization of 2-aminobenzamides and aldehydes catalyzed by p-toluenesulfonic acid followed by an efficient PIDA-mediated oxidative dehydrogenation enables the synthesis of various 4(3H)-quinazolinones - including quinazolinones bearing an N-alkoxy substituent. The method offers mild reaction conditions.
R. Cheng, T. Guo, D. Zhang-Negrerie, Y. Du, K. Zhao, Synthesis, 2013, 45, 2998-3006.

An efficient intermolecular amidation of quinoline N-oxides with sulfonamides in the presence of PhI(OAc)₂ and PPh₃ provides N-(quinolin-2-yl)sulfonamides in very good yields.
X. Yu, S. Yang, Y. Zhang, M. Guo, Y. Yamaoto, M. Bao, Org. Lett., 2017, 19, 6088-6091.

A highly atom-efficient PIDA-mediated intramolecular iminoenol tautomer trapping reaction, followed by Et₃N-promoted aerobic oxidative ring construction enables the synthesis of multisubstituted 2-hydroxy-benzo[b][1,4]oxazins from N-(2-hydroxylaryl)enaminones at room temperature under air. O₂ serves as the oxygen source of the hydroxyl group.
H. Zhang, J. Shen, G. Cheng, Y. Feng, X. Cui, Org. Lett., 2018, 20, 664-667.

A new Pd-catalyzed oxidation reaction for the stereospecific conversion of enynes into cyclopropyl ketones proceeds with net inversion of geometry with respect to the starting olefin. This result is consistent with a mechanism in which the key cyclopropane-forming step involves nucleophilic attack of a tethered olefin onto the Pd^IV-C bond.
L. L. Welbes, T. W. Lyons, K. A. Cychosz, M. S. Sanford, J. Am. Chem. Soc., 2007, 129, 5836-5837.

Acetyl hypoiodite (CH₃CO₂I) is readily generated in situ by oxidation of molecular iodine by (diacetoxyiodo)benzene (DAIB) and can be utilized for the synthesis of 1,2-iodo-cofunctionalized derivatives of alkenes. Conversion of both atoms of molecular iodine to I⁺ results in 100% iodine atom economy for the reported iodo-cofunctionalization of alkenes.
H. Gottam, T. K. Vinod, J. Org. Chem., 2011, 76, 974-977.

Treatment of terminal alkynes with (diacetoxyiodo)benzene, potassium iodide, and copper(I) iodide afforded 1-iodoalkynes in good to excellent yields under mild conditions.
J. Yan, J. Li, D. Cheng, Synlett, 2007, 2442-2444.

Hypervalent iodine reagents mediate practical oxidative iodinations for the chemoselective mono-, di-, and tri-iodination of alkynes. The reaction conditions were systematically optimized by altering the iodine source and/or the hypervalent iodine reagent system.
Y. Liu, D. Huang, J. Huang, K. Maruoka, J. Org. Chem., 2017, 82, 11865-11871.

Phenyliodonium ylides provide easy access to various 1,1-cyclopropane diesters using rhodium or copper catalysis and are safer and convenient alternatives to the corresponding diazo compounds. Moreover, the iodonium ylide of dimethyl malonate was obtained in 78% yield using improved conditions that involve a simple filtration step to isolate the desired product.
S. R. Goudreau, D. Marcoux, A. B. Charette, J. Org. Chem., 2009, 74, 470-473.

An efficient oxidative amination of sulfenamides using diacetoxyiodobenzene (PhI(OAc)₂) and amines provides sulfinamidines in very good yields under mild, metal-free conditions. Furthermore, possible pathways are proposed that elucidate the observed molecular sequence of events in this reaction.
G. Huang, J. Ye, M. A. Bashir, Y. Chen, W. Chen, X. Lu, J. Org. Chem., 2023, 88, 11728-11734.

A rhodium-catalyzed transfer of carbamates to sulfoxides enables a convenient synthesis of N-protected sulfoximines under mild conditions. Sulfoximines, including 4-membered thietane-oximines, bearing Boc and Cbz groups are readily deprotected.
M. Zenzola, R. Doran, R. Luisi, J. A. Bull, J. Org. Chem., 2015, 80, 6391-6399.