19230-50-3Relevant articles and documents
Synthesis, characterization and initial evaluation of 5-nitro-1- (trifluoromethyl)-3H-1λ3,2-benziodaoxol-3-one
Santschi, Nico,Sarott, Roman C.,Otth, Elisabeth,Kissner, Reinhard,Togni, Antonio
, p. 1 - 6 (2014)
The synthesis of 5-nitro-1-(trifluoromethyl)-3H-1λ3,2- benziodaoxol-3-one (3), a hypervalent-iodine-based electrophilic trifluoromethylating reagent, is described. Whereas considerations based on cyclic voltammetry and X-ray structural properties would predict an inferior reactivity when compared to the non-nitrated derivative 2, 19F NMR kinetic studies showed that this new derivative is almost one order of magnitude more reactive. Furthermore, differential scanning calorimetry measurements indicated that, in addition, it is also safer to handle.
Synthesis of isocoumarins via Pd/C-mediated reactions of o-iodobenzoic acid with terminal alkynes
Subramanian, Venkataraman,Batchu, Venkateswara Rao,Barange, Deepak,Pal, Manojit
, p. 4778 - 4783 (2005)
The coupling reaction of o-iodobenzoic acid with terminal alkynes by using a catalyst system of 10% Pd/C-Et3N-CuI-PPh3 has been studied in a variety of solvents. 3-Substituted isocoumarins were formed in good yields and with good reg
Singlet Oxygen Generation from a Water-Soluble Hypervalent Iodine(V) Reagent AIBX and H2O2: An Access to Artemisinin
Hu, Ze-Nan,Shen, Hui-Jie,Zhang, Chi
supporting information, (2021/06/21)
Herein, we report an efficient method for the chemical generation of 1O2 by treatment of H2O2 with AIBX, a highly water-soluble, bench-stable, recyclable hypervalent iodine(V) reagent developed by our group. The generation of 1O2 was confirmed by the following results: (1) capture of 1O2 with the sodium salt of anthracene-9,10-bis(ethanesulfonate) produced the corresponding endoperoxide and (2) TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) produced by the oxidation of 2,2,6,6-tetramethylpiperidine with 1O2 generated using the AIBX/H2O2 system was detected by electron spin resonance spectroscopy. To illustrate the potential utility of this method for organic synthesis, we used the AIBX/H2O2 system to perform typical reactions of 1O2: [2 + 2]/[4 + 2] cycloadditions, Schenck ene reactions, and heteroatom oxidation reactions, which afforded the corresponding products in high yields. Moreover, we used the method to synthesize the antimalarial drug artemisinin. Finally, we demonstrated that AIBX could be regenerated after the reaction by means of a workup involving extraction and removal of water to obtain a precursor of AIBX, which could then be re-oxidized.
One-Pot Synthesis and Conformational Analysis of Six-Membered Cyclic Iodonium Salts
Caspers, Lucien D.,Spils, Julian,Damrath, Mattis,Lork, Enno,Nachtsheim, Boris J.
, p. 9161 - 9178 (2020/08/14)
Two one-pot procedures for the construction of carbon-bridged diaryliodonium triflates and tetrafluoroborates are described. Strong Br?nsted acids enable the effective Friedel-Crafts alkylation with diversely substituted o-iodobenzyl alcohol derivatives, providing diphenylmethane scaffolds, which are subsequently oxidized and cyclized to the corresponding dibenzo[b,e]iodininium salts. Based on NMR investigations and density functional theory (DFT) calculations, we could verify the so-far-undescribed existence of two stable isomers in cyclic iodonium salts substituted with aliphatic side chains in the carbon bridge.
One-Pot C-H Arylation/Lactamization Cascade Reaction of Free Benzylamines
Chand-Thakuri, Pratibha,Landge, Vinod G.,Kapoor, Mohit,Young, Michael C.
, p. 6626 - 6644 (2020/07/14)
An efficient method has been developed for the synthesis of seven-membered biaryl lactams involving Pd-catalyzed, native amine-directed, ortho-arylation of benzylamines followed by in situ lactamization. This cascade sequence is enabled by the use of 2-iodobenzoates, which facilitates C-H arylation from the free amine under conditions that typically require an improved directing group approach. This reaction is characterized by a broad substrate scope with good functional group tolerance. The need for an ester versus carboxylic acid-functionalized coupling partner is also explored, as is the potential for synthesizing eight-membered biaryl lactams. Various applications are also investigated, including access to the aza-brassinolide core.
[Bis(trifluoroacetoxy)iodo]p-nitrobenzene and [bis(trifluoroacetoxy)iodo]pentafluorobenzene as lead reagents for the direct ring contraction of lactams to pyrrolidines
Aubert-Nicol, Samuel,Heinrich, Nora,Lessard, Jean,Spino, Claude
, p. 484 - 501 (2019/08/01)
Two 3-iodanes, namely [bis(trifluoroacetoxy)iodo]p-nitrobenzene and [bis(trifluoroacetoxy)iodo]pentafluorobenzene, were used to effect the direct ring-contraction of lactams to pyrrolidines. Intense reaction optimization was necessary but only
Regioselectivity Influences in Platinum-Catalyzed Intramolecular Alkyne O-H and N-H Additions
Costello, Jeff P.,Ferreira, Eric M.
supporting information, p. 9934 - 9939 (2019/12/24)
The steric and electronic drivers of regioselectivity in platinum-catalyzed intramolecular hydroalkoxylation are elucidated. A branch point is found that divides the process between 5-exo and 6-endo selective processes, and enol ethers can be accessed in good yields for both oxygen heterocycles. The main influence arises from an electronic effect, where the alkyne substituent induces a polarization of the alkyne that leads to preferential heteroatom attack at the more electron-deficient carbon. The electronic effects are studied in other contexts, including hydroacyloxylation and hydroamination, and similar trends in directionality are predominant although not uniformly observed.
Oxidation of secondary alcohols using solid-supported hypervalent iodine catalysts
Ballaschk, Frederic,Kirsch, Stefan F.
supporting information, p. 5896 - 5903 (2019/11/11)
It is shown how secondary alcohols are oxidized to provide the corresponding ketones by use of Oxone and solid-supported hypervalent iodine catalysts. Under experimentally simple conditions with acetonitrile at elevated temperatures, excellent conversions were achieved with low catalyst loadings (0.2-5 mol%) when employing the conjugates 5 and 6 derived from IBX and IBS. The catalysts are broadly applicable to a range of alcohol substrates. Of primary importance with respect to sustainability issues, the metal-free catalysts are easily removed from the reaction mixture through filtration, and they can be re-used in oxidation processes for multiple times, without loss of catalytic activity.
2-Iodo-N-isopropyl-5-methoxybenzamide as a highly reactive and environmentally benign catalyst for alcohol oxidation
Yakura, Takayuki,Fujiwara, Tomoya,Yamada, Akihiro,Nambu, Hisanori
supporting information, p. 971 - 978 (2019/11/11)
Several N-isopropyliodobenzamides were evaluated as catalysts for the oxidation of benzhydrol to benzophenone in the presence of Oxone (2KHSO5·KHSO4·K2SO4) as a co-oxidant at room temperature. A study on the substituent effect of the benzene ring of N-isopropyl-2-iodobenzamide on the oxidation revealed that its reactivity increased in the following order of substitution: 5-NO2 2Me, 3-OMe 5-OAc 5-Cl H, 4-OMe 5-Me 5-OMe. The oxidation of various benzylic and aliphatic alcohols using a catalytic amount of the most reactive 5-methoxy derivative successfully resulted in moderate to excellent yields of the corresponding carbonyl compounds. The high reactivity of the 5-methoxy derivative at room temperature is a result of the rapid generation of the pentavalent species from the trivalent species during the reaction. 5-Methoxy-2-iodobenzamide would be an efficient and environmentally benign catalyst for the oxidation of alcohols, especially benzylic alcohols.
Palladium-Catalyzed, Norbornene-Mediated, ortho-Amination ipso-Amidation: Sequential C-N Bond Formation
Whyte, Andrew,Olson, Maxwell E.,Lautens, Mark
supporting information, p. 345 - 348 (2018/01/27)
A palladium-catalyzed, norbornene-mediated ortho- and ipso-C-N bond-forming Catellani reaction is reported. This reaction proceeds through a sequential intermolecular amination followed by intramolecular cyclization of a tethered amide. The products, ortho-aminated dihydroquinolinones, were generated in moderate to good yields and are present in bioactive molecules. This work highlights the challenge of competing intra- vs intermolecular palladium-catalyzed processes.
