35024-12-5Relevant articles and documents
CO2-activated NaClO-5H2O enabled smooth oxygen transfer to iodoarene: A highly practical synthesis of iodosylarene
Miyamoto, Kazunori,Watanabe, Yuichiro,Takagi, Taisei,Okada, Tomohide,Toyama, Takashi,Imamura, Shinji,Uchiyama, Masanobu
, (2021/05/27)
A safe, rapid, and environmentally friendly synthesis of iodosylarene (ArIO) has been developed using NaClO under a carbon dioxide (CO2) atmosphere. Exposure of iodoarene to NaClO-5H2O in acetonitrile under CO2 (1 atm) resulted in the clean formation of ArIO within 10 minutes in high yield. The absence of a base in this method enables the direct use of in-situ-generated iodosylarene not only for a variety of oxidative transformations (synthesis of sulfilimine, pentavalent bismuth, benzyne adduct, etc.), but also for the synthesis of iodonium ylide and imino-λ3-iodane in one pot.
Rh(III)-Catalyzed Chemodivergent Annulations between Indoles and Iodonium Carbenes: A Rapid Access to Tricyclic and Tetracyclic N-Heterocylces
Kanchupalli, Vinaykumar,Kumar, Sanjeev,Nanduri, Srinivas,Nunewar, Saiprasad,Pandhare, Harishchandra
supporting information, p. 4233 - 4238 (2021/06/28)
Herein, we report an acid-controlled highly tunable selectivity of Rh(III)-catalyzed [4 + 2] and [3 + 3] annulations of N-carboxamide indoles with iodonium ylides lead to form synthetically important tricyclic and tetracyclic N-heterocycles. Here, iodonium ylide serves as a carbene precursor. The protocol proceeds under operationally simple conditions and provides novel tricyclic and tetracyclic scaffolds such as 3,4-dihydroindolo[1,2-c]quinazoline-1,6(2H,5H)-dione and 1H-[1,3]oxazino[3,4-a]indol-1-one derivatives with a broad range of functional group tolerance and moderate to excellent yields. Furthermore, the protocol synthetic utility was extended for various chemical transformations and was easily scaled up to a large-scale level.
Rh(iii)-Catalyzed C(sp2)-H functionalization/cyclization cascade of: N -carboxamide indole and iodonium reagents for access to indoloquinazolinone derivatives
Han, Zhi-Peng,Ji, Shun-Jun,Xu, Meng-Meng,Xu, Xiao-Ping,Zhang, Rui-Ying
supporting information, p. 6337 - 6340 (2021/09/10)
A rhodium-catalyzed synthesis of indoloquinazolinone from a readily available hypervalent iodonium reagent and N-carboxamide indole was developed. The protocol features broad functional group tolerance, mild conditions, and excellent yields. The target products were obtained simply by filtration, without tedious column chromatography. Notably, the noble metal catalyst system can be recycled effectively at least ten times. The strategy may be amenable to industrial production.
Iodonium Ylides as Carbene Precursors in Rh(III)-Catalyzed C-H Activation
Jiang, Yuqin,Li, Pengfei,Li, Xingwei,Liu, Bingxian,Zhao, Jie
supporting information, p. 7475 - 7479 (2020/10/12)
The rhodium(III)-catalyzed coupling of C-H substrates with iodonium ylides has been realized for the efficient synthesis of diverse cyclic skeletons, where the iodonium ylides have been identified as efficient and outstanding carbene precursors. The reaction systems are applicable to both sp2 and sp3 C-H substrates under mild and redox-neutral conditions. The catalyst loading can be as low as 0.5 mol % in a gram-scale reaction. Representative products exhibit cytotoxicity toward human cancer cells at nanomolar levels.
Harnessing hypervalent iodonium ylides as carbene precursors: C-H activation of: N -methoxybenzamides with a Rh(iii)-catalyst
Mayakrishnan, Sivakalai,Tamizmani, Masilamani,Maheswari, Naryanan Uma
supporting information, p. 15462 - 15465 (2020/12/25)
Hypervalent iodonium ylides expeditiously generate carbenes which undergo domino intermolecular C-H activation followed by intramolecular condensation in the presence of N-methoxybenzamide as a starting material and a Rh(iii)-catalyst to afford dihydrophenanthridines. KIE studies and DFT calculations were performed to substantiate the mechanistic pathway. To extend the synthetic utilisation, fluorescent pyranoisocoumarins were achieved by using Rh(iii)-catalyzed peri-C-H/O-H activation/annulation reactions.
Blue LED Irradiation of Iodonium Ylides Gives Diradical Intermediates for Efficient Metal-free Cyclopropanation with Alkenes
Chidley, Tristan,Jameel, Islam,Rizwan, Shafa,Peixoto, Philippe A.,Pouységu, Laurent,Quideau, Stéphane,Hopkins, W. Scott,Murphy, Graham K.
supporting information, p. 16959 - 16965 (2019/11/11)
A facile and highly chemoselective synthesis of doubly activated cyclopropanes is reported where mixtures of alkenes and β-dicarbonyl-derived iodonium ylides are irradiated with light from blue LEDs. This metal-free synthesis gives cyclopropanes in yields
Aryliodonium ylides as novel and efficient additives for radical chemistry: Example in Camphorquinone (CQ)/Amine based photoinitiating systems
Kirschner, Julie,Paillard, Julien,Bouzrati-Zerelli, Mariem,Becht, Jean-Michel,Klee, Joachim E.,Chelli, Saloua,Lakhdar, Sami,Lalevée, Jacques
, (2019/08/20)
Diaryliodonium salts are well-established compounds in free radical chemistry and are already used as photoinitiators (free radical or cationic polymerization), but the presence of counter anions is a strong drawback. Indeed, a counter anion is always req
Support-Free Pd3Co NCs as an Efficient Heterogeneous Nanocatalyst for New Organic Transformations of C?C Coupling Reactions
Pradhan, Samjhana,Mishra, Kanchan,Lee, Yong Rok
supporting information, p. 10886 - 10894 (2019/08/02)
A support-free heterogeneous Pd3Co nanostructured composite (NC), synthesized through a hydrothermal route, acted as an effective catalytic system in multivariate Heck-, Sonogashira-, and Suzuki-type coupling reactions of iodonium ylides. The XPS analysis of the bimetallic Pd3Co NCs confirmed the elemental composition as 75 % palladium and 25 % cobalt. Furthermore, high-resolution (HR) TEM analysis confirmed the spherical morphology of the Pd3Co bimetallic nanoparticles. The average diameter of the NCs is 14.8 nm. The coupling reaction proceeded through the generation of α-iodoenones with simultaneous migration of the phenyl group, thereby giving a scaffold with higher atom economy. The heterogeneous Pd3Co NCs were recycled and reused without any significant change in catalytic ability for up to five reaction cycles. The high concentration of Pd and association of cobalt into the lattice of palladium appears to enhance its catalytic ability for the diverse coupling reactions in comparison with its monometallic counterparts as well as with bimetallic NCs with a comparatively lesser amount of Pd.
Safer Synthesis of (Diacetoxyiodo)arenes Using Sodium Hypochlorite Pentahydrate
Watanabe, Ayumi,Miyamoto, Kazunori,Okada, Tomohide,Asawa, Tomotake,Uchiyama, Masanobu
, p. 14262 - 14268 (2018/11/23)
A practical method for the preparation of (diacetoxyiodo)arene ArI(OAc)2 is described. The use of commercially available sodium hypochlorite pentahydrate (NaClO·5H2O) enabled safe, rapid, and inexpensive oxidation of iodoarenes with electron-withdrawing and -donating substituents. The method allows tandem divergent access to synthetically useful organo-λ3-iodanes such as hydroxyl(tosyloxy)iodobenzene, iodosylbenzene, iodonium ylide, etc.
Nucleophilicity Parameters of Stabilized Iodonium Ylides for Characterizing Their Synthetic Potential
Chelli, Saloua,Troshin, Konstantin,Mayer, Peter,Lakhdar, Sami,Ofial, Armin R.,Mayr, Herbert
, p. 10304 - 10313 (2016/09/03)
Kinetics and mechanisms of the reactions of the β-dicarbonyl-substituted iodonium ylides 1(a-d) with several π-conjugated carbenium and iminium ions have been investigated. All reactions proceed with rate-determining attack of the electrophile at the nucleophilic carbon center of the ylides to give iodonium ions, which rapidly expel iodobenzene and undergo different subsequent reactions. The second-order rate constants k2 for the reactions of the iodonium ylides with benzhydrylium ions correlate linearly with the electrophilicity parameters E of the benzhydrylium ions and thus follow the linear free energy relationship log k(20 °C) = sN(N + E) (eq 1), where electrophiles are characterized by one parameter (E), while nucleophiles are characterized by two parameters: the nucleophilicity N and the susceptibility sN. The nucleophilicity parameters 4 + at the carbanionic center of Meldrum's acid or dimedone, respectively, reduces the nucleophilicity by approximately 10 orders of magnitude. The iodonium ylides 1(a-d) thus have nucleophilicities similar to those of pyrroles, indoles, and silylated enol ethers and, therefore, should be suitable substrates in iminium-activated reactions. Good agreement of the measured rate constant for the cyclopropanation of the imidazolidinone-derived iminium ion 10a with the iodonium ylide 1a with the rate constant calculated by eq 1 suggests a stepwise mechanism in which the initial nucleophilic attack of the iodonium ylide at the iminium ion is rate-determining. The reaction of cinnamaldehyde with iodonium ylide 1a catalyzed by (5S)-5-benzyl-2,2,3-trimethyl-imidazolidin-4-one (11a, MacMillan's first-generation catalyst) gives the corresponding cyclopropane with an enantiomeric ratio of 70/30 and, thus, provides proof of principle that iodonium ylides are suitable substrates for iminium-activated cyclopropanations.
