6973-73-5Relevant academic research and scientific papers
Preparation and Synthetic Applicability of Imidazole-Containing Cyclic Iodonium Salts
Antonkin, Nikita S.,Vlasenko, Yulia A.,Yoshimura, Akira,Smirnov, Vladimir I.,Borodina, Tatyana N.,Zhdankin, Viktor V.,Yusubov, Mekhman S.,Shafir, Alexandr,Postnikov, Pavel S.
, p. 7163 - 7178 (2021/05/29)
A novel approach to the preparation of imidazole-substituted cyclic iodonium salts has been developed via the oxidative cyclization of 1-phenyl-5-iodoimidazole using a cheap and available Oxone/H2SO4 oxidative system. The structure of the new polycyclic heteroarenes has been confirmed by single-crystal X-ray diffractometry, revealing the characteristic structure features for cyclic iodonium salts. The newly produced imidazole-flanked cyclic iodonium compounds were found to readily engage in a heterocyclization reaction with elemental sulfur, affording benzo[5,1-b]imidazothiazoles in good yields.
The Role of Iodanyl Radicals as Critical Chain Carriers in Aerobic Hypervalent Iodine Chemistry
Hyun, Sung-Min,Yuan, Mingbin,Maity, Asim,Gutierrez, Osvaldo,Powers, David C.
supporting information, p. 2388 - 2404 (2019/09/12)
Selective O2 utilization remains a substantial challenge in synthetic chemistry. Biological small-molecule oxidation reactions often utilize aerobically generated high-valent catalyst intermediates to effect substrate oxidation. Available synthetic methods for aerobic oxidation catalysis are largely limited to substrate functionalization chemistry by low-valent catalyst intermediates (i.e., aerobically generated Pd(II) intermediates). Motivated by the need for new chemical platforms for aerobic oxidation catalysis, we recently developed aerobic hypervalent iodine chemistry. Here, we report that in contrast to the canonical two-electron oxidation mechanisms for the oxidation of organoiodides, the developed aerobic hypervalent iodine chemistry proceeds via a radical chain mechanism initiated by the addition of aerobically generated acetoxy radicals to aryl iodides. Despite the radical chain mechanism, aerobic hypervalent iodine chemistry displays substrate tolerance similar to that observed with traditional terminal oxidants, such as peracids. We anticipate that these insights will enable new sustainable oxidation chemistry via hypervalent iodine intermediates. O2 is routinely utilized in biological catalysis to generate high-valent catalyst intermediates that engage in substrate oxidation chemistry. Analogous synthetic chemistry via aerobically generated high-valent intermediates would enable new sustainable synthetic methods but is largely unknown because of the challenges in selective O2 utilization. We have developed aerobic hypervalent iodine chemistry as a platform for coupling O2 reduction with a diverse set of substrate functionalization mechanisms. Many of the synthetic applications of hypervalent iodine reagents rely on selective two-electron oxidation-reduction chemistry. Here, we report that one-electron oxidation reactions pathways via iodanyl radical intermediates are critical in aerobic hypervalent iodine chemistry. The new appreciation for the critical role that iodanyl radicals can play in the synthesis of hypervalent iodine compounds will provide new opportunities in sustainable oxidation catalysis. Aerobic hypervalent iodine chemistry provides a strategy for coupling the one-electron chemistry of O2 with two-electron processes typical of organic synthesis. We show that in contrast to the canonical two-electron oxidation of aryl iodides, aerobic synthesis proceeds by a radical chain process initiated by the addition of aerobically generated acetoxy radicals to aryliodides to generate iodanyl radicals. Robustness analysis reveals that the developed aerobic oxidation chemistry displays substrate tolerance similar to that observed in peracid-based methods and thus holds promise as a sustainable synthetic method.
Synthesis of O -Aroyl- N, N -dimethylhydroxylamines through Hypervalent Iodine-Mediated Amination of Carboxylic Acids with N, N -Dimethylformamide
Zhang, Chuancheng,Yue, Qiang,Xiao, Zhen,Wang, Xianglan,Zhang, Qian,Li, Dong
supporting information, p. 4303 - 4308 (2017/09/13)
An efficient protocol for the synthesis of O -aroyl- N, N -dimethylhydroxylamines, which are important electrophilic amination reagents, is described. The reaction between carboxylic acids and N, N -dimethylformamide is mediated by hypervalent iodine and
NH-Heterocyclic Aryliodonium Salts and their Selective Conversion into N1-Aryl-5-iodoimidazoles
Wu, Yichen,Izquierdo, Susana,Vidossich, Pietro,Lledós, Agustí,Shafir, Alexandr
supporting information, p. 7152 - 7156 (2016/07/06)
The synthesis of N-arylimidazoles substituted at the sterically encumbered 5-position is a challenge for modern synthetic approaches. A new family of imidazolyl aryliodonium salts is reported, which serve as a stepping stone on the way to selective formation of N1-aryl-5-iodoimidazoles. Iodine acts as a “universal” placeholder poised for replacement by aryl substituents. These new λ3-iodanes are produced by treating the NH-imidazole with ArI(OAc)2, and are converted to N1-aryl-5-iodoimidazoles by a selective copper-catalyzed aryl migration. The method tolerates a variety of aryl fragments and is also applicable to substituted imidazoles.
Tandem catalytic C(sp3)-H amination/sila-sonogashira-hagihara coupling reactions with iodine reagents
Buendia, Julien,Darses, Benjamin,Dauban, Philippe
supporting information, p. 5697 - 5701 (2015/06/16)
A new tandem C-N and C-C bond-forming reaction has been achieved through RhII/Pd0 catalysis. The sequence first involves an iodine(III) oxidant, then the in situ generated iodine(I) by-product is used as a coupling partner. The overall process demonstrates the synthetic value of iodoarenes produced in trivalent iodine reagent mediated oxidations. I(003) is a double agent: A tandem C-N and C-C bond-forming reaction has been achieved through RhII/Pd0 catalysis. The sequence first involves an iodine(III) oxidant, then the in situ generated iodine(I) by-product is used as a coupling partner. The overall process affords complex building blocks with high yields, and demonstrates the synthetic value of iodoarenes produced in trivalent iodine reagent mediated oxidations.
Synthesis and reactivity of aryl(alkynyl)iodonium salts
Dixon, Luke I.,Carroll, Michael A.,Gregson, Thomas J.,Ellames, George J.,Harrington, Ross W.,Clegg, William
supporting information, p. 2334 - 2345 (2013/05/21)
The first practical, yet simple, preparation of aryl(alkynyl)iodonium trifluoroacetate salts is described. The generic nature of this synthetic method has allowed the production of a range of aryl(alkynyl)iodonium trifluoroacetate salts with independent variation of both the alkynyl and aryliodo groups in yields of 30-85 %. Application of these new reagents to the synthesis of a series of 2-arylfuro[3,2-c]pyridines (40-64 %) highlights the potential of this class of materials as precursors to bioactive heterocyclic structures. These experiments have also demonstrated that, in this case, the effect of the aryliodo group on the reaction is negligible.
Direct arylation of benzoxazole C-H bonds with iodobenzene diacetates
Yu, Peng,Zhang, Guangyou,Chen, Fan,Cheng, Jiang
supporting information; experimental part, p. 4588 - 4590 (2012/09/22)
A Pd (OAc)2-catalyzed direct arylation of benzoxazole C-H bonds has been achieved with iodobenzene diacetates as the arylation reagent in moderate to good yields. The procedure tolerates a series of functional groups, such as methoxy, nitro, cyano, chloro, and bromo groups.
Approach to the synthesis of indoline derivatives from diaryliodonium salts
Landge, Kamalkishor P.,Jang, Keun Sam,Lee, Sang Yeul,Chi, Dae Yoon
experimental part, p. 5705 - 5713 (2012/09/07)
An effective method of constructing the indoline moiety via intramolecular nucleophilic ring closure of a diaryliodonium salt is described. Diacetoxyiodoarene compounds (1a-1e) were converted into intermediate Koser's reagent and coupled with arylstannanes (7-10) to form diaryliodonium salts (11a-14e). Indoline compounds with different N-protecting groups, 15, 16, 17, and 18, were synthesized in higher yields by treating salts (11a-14e) with Cs2CO3 and TEMPO. Regardless of the electronic environment of five para-substituted iodoarenes and the natures of four N-protected arylstannane groups, the conversion proceeded well to afford corresponding indolines in yields of 72-84 and 70-84%, respectively.
4-ARYLOXYQUINOLIN-2(1H)-ONES AS MTOR KINASE AND PI3 KINASE INHIBITORS, FOR USE AS ANTI-CANCER AGENTS
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Page/Page column 60, (2010/04/06)
4-aryloxyquinolin-2(1H)-ones as mtor kinase and PI3 kinase inhibitors, for use as anti-cancer agents. Compounds of the formula I and pharmaceutically acceptable salts thereof, wherein A, B, R1, R2, R3, R4, R5, R6, and R7 are defined as set forth herein are disclosed. Also disclosed are pharmaceutical compositions comprising the compounds of the invention and a pharmaceutically acceptable carrier, methods of making the compounds of the invention and methods of using the compounds for inhibiting mTOR and PI3 kinases and for treating cancers.
New and direct approach to hypervalent iodine compounds from arenes and iodine. straightforward synthesis of (diacetoxyiodo)arenes and diaryliodonium salts using potassium μ-peroxo-hexaoxodisulfate
Hossain, Md. Delwar,Kitamura, Tsugio
experimental part, p. 2213 - 2219 (2009/08/08)
The reaction of arenes with elemental iodine, acetic acid, and potassium μ-peroxo-hexaoxodisulfate (K2S2O8) in the presence of concentrated sulfuric acid, efficiently generated the corresponding (diacetoxyiodo)arenes in good yields. Diaryliodonium triflates were directly synthesized by reaction of arenes with elemental iodine in good yields by using K2S2O8, AcOH, and TfOH. Diaryliodonium tosylates were also prepared from arenes and elemental iodine by using K 2S2O8, AcOH, H2SO4, and TsOH. The procedure involved mild conditions and a straightforward one-pot synthesis.
