Received 2021 Dec 22; Accepted 2022 Jan 11. SYNLETT 25, 403406. A stabilized formulation of IBX (SIBX) for safe oxidation reactions including a new oxidative demethylation of phenolic methyl aryl ethers. It is followed by IBX-supported oxidative aromatization affording the title compounds. The aromatic functional groups were well tolerated, and indole 113) nitrogen need not be protected for the reactions to proceed fruitfully under the present reaction conditions. Disclaimer. (2017). Epub 2015 Dec 9. official website and that any information you provide is encrypted After screening temperatures and stoichiometries, authors employed IBX (1 equiv) and TEAB (1.2 equiv) for the oxidative cyclization. It involves catalyst-free nucleophilic addition of amines 2) on benzoxazoles (107) under solvent-free conditions, followed by IBX-assisted oxidative ring closure. A polar aprotic solvent such as acetonitrile provided high yields of the desired compound. A green approach for the synthesis of a library of 3,4-dihydro pyrimidine-2(1H)-ones 21) (DHPMS) in the water medium, via the Biginelli reaction was developed by Santosh Takale and co-authors employing several aromatic aldehydes (22), -keto esters 23) such as methyl/ethyl acetoacetate, and thiourea/urea 24) as reactants in the presence of iodoxybenzoic acid at 60C (Supplementary Figure S9) (Takale et al., 2011). An interesting mild one-pot two-step metal-free methodology for synthesizing tetracyclic oxazepine-fused pyrrole scaffolds 42) was explored by Sachin Choudhary and co-researchers through [3 + 2] the annulation strategy between dibenzo [b,f][1,4] oxazepines 43) and aqueous succinaldehyde 29) involving proline-catalyzed direct Mannich/cyclization followed by the IBX-supported oxidation sequence (Supplementary Figure S18) (Choudhary et al., 2019). Inclusion in an NLM database does not imply endorsement of, or agreement with, ABAB Phthalocyanines: Scaffolds for Building Unprecedented Donor--Acceptor Chromophores. doi:10.1016/j.tetlet.2013.06.045, Chi, Y., Zhang, W.-X., and Xi, Z. (2019). Download scientific diagram | Scheme 4. doi:10.1055/s-0035-1560416, Silva, T. S., Zeoly, L. A., and Coelho, F. (2020). A Facile and Expeditious One-Pot Synthesis of -Keto-1,3,4-oxadiazoles. Authors noticed that in the absence of -CD, these reactions did not result in satisfactory yields of the aromatized products. doi:10.1039/C9OB01267B, Kandimalla, S. R., Parvathaneni, S. P., Sabitha, G., and Subba Reddy, B. V. (20192019). doi:10.1021/acs.jnatprod.7b00665, Charpentier, J., Frh, N., and Togni, A. and transmitted securely. The process allows recycling and reuse of IBX and found to be scalable. The https:// ensures that you are connecting to the A broad range of 1,4-dibenzoxazepines 43) decorated with a variety of electron-withdrawing and electron-donating functionalities in both rings was exploited as convenient substrates for the protocol. (2014). Charpentier J., Frh N., Togni A. During optimization studies, authors examined the feasibility and effects of different temperature conditions and stoichiometries. o-Iodoxybenzoic Acid (IBX): a Versatile Reagent for the Synthesis of N-Substituted Pyrroles Mediated by -cyclodextrin in Water. Matrine-type alkaloids (72), having broad and potent biological activities, are widely present in the Sophora flavescens, S. alopecuroides, and S. subprostrara. Singh A., Mir N. A., Choudhary S., Singh D., Sharma P., Kant R., et al. doi:10.1016/j.tet.2010.10.053, Makra, Z., Pusks, L. G., and Kanizsai, I. The protocol was efficiently applied for generating diverse bioactive fused heterocyclic scaffolds such as pyrrolo-oxadiazole, dihydro pyrrolo-quinoline, pyrrolo-quinoline, and pyrrolophenanthridine. Hypervalent Iodine Reactions Utilized in Carbon-Carbon Bond Formations. doi:10.1016/j.tetlet.2009.07.155, Patil, P., Nimonkar, A., and Akamanchi, K. G. (2014). doi:10.1016/j.tetlet.2020.151749, Li, C., Liu, Y., and Wang, Q. J. Copyright 2022 Venkata Durga Nageswar, Ramesh and Rakhi. The Mechanism of Dess-Martin Oxidation. (2019). Further scope of the applications of IBX may widen in coming years, with more preparations of soluble as well as recyclable modifications of IBX coming out and refinement of working methodologies. Synthesis of Polycyclic spiro-fused Indolines via IBX-Mediated cascade Cyclization. Chem. official website and that any information you provide is encrypted Authors explained the reaction mechanism. Matrine-type alkaloids (72), having broad and potent biological activities, are widely present in the Sophora flavescens, S. alopecuroides, and S. subprostrara. (2009). 85, 54385448. The authors of this review acknowledge the original contributors and publishers of the articles cited here. For the oxidation step, authors screened oxidants such as DMP, PCC, and Swern apart from IBX. The reactions proceeded with high regioselectivity with regard to C-3 position of indolizines (67), since C-1 position was less nucleophilic than C-3. One-pot Sequential Multicomponent Reaction between. doi:10.1016/j.tet.2010.06.014, Binder, J. T., and Kirsch, S. F. (2006). In either case, a hydroxyl group on C-5, due to hydrogen bond formation with oxygen of the carbonyl group on C-4 hindered the formation of the 5-5-iodanyl complex with IBX, making both 5-hydroxy flavone 94) and 5-hydroxy flavanone 88) unreactive irrespective of reaction temperatures. These hypervalent iodine (III) compounds represent attractive oxidizing agents due to their selective actions and stability. IBX Mediated Reaction of -enamino Esters with Allylic Alcohols: a One Pot Metal Free Domino Approach to Functionalized Pyridines. Advances in Synthetic Applications of Hypervalent Iodine Compounds. 8, 1544815458. A Simple Protocol for the Synthesis of 2-arylbenzoxazoles by Oxidation with O-Iodoxybenzoic Acid (IBX) and its Application in the Synthesis of Arylbenzoxazole-Containing Amino Acids. Ed. Title compounds are obtained by the dehydration and decarboxylation from these intermediates in excellent yields. HHS Vulnerability Disclosure, Help Tetrahedron. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). The best results observed that 2.0 equivalents of IBX and 1.2 equivalents of phenylhydrazine were used. These bromohydrins 13) were later converted successfully into 1, 2, 3-triketones 14) by the IBX-mediated oxidation in DMSO under room temperature conditions (Verma et al., 2017). The https:// ensures that you are connecting to the Bethesda, MD 20894, Web Policies l Also demonstrated is the in situ (re)oxidation of 2-iodosobenzoic acid (IBA) and The stoichiometry of IBX and TEA was fixed after studies. Various amino groups on the side chain, such as NHCbZ, NHBoc, and N3 were tolerated, and N-unprotected substrate did not give the product. The desired products were obtained in the range of 5096%. Tetrahedron Lett. (2015). The present review highlights research reports on IBX-assisted transformations in heterocyclic derivatives, particularly from 2010 onward. unveiled that IBX promoted mild and selective oxidation of unactivated cyclic amines (2b) to imines (25), employing a range of aliphatic meso-pyrrolidines (2b) as substrates (Supplementary Figure S10) (de Graaff et al., 2015) The protocol was further applied for diastereoselective oxidative Ugi-type and aza-FriedelCrafts reactions (26, 27) (Supplementary Figures S11,S12). Nishanth Verma and co-authors employed LiBr/-CD in the H2ODMSO mixture for highly regioselective ring cleavage of epoxides 12) affording bromohydrins 13) (Supplementary Figure S6). Chaojie Li and co-authors in an interesting research communication described a metal-free, eco-friendly, and operationally simple approach for the semisynthesis of sophocarpine 73) from matrine 72) in 91% yield, via the formation of 14-phenyl sulfinyl matrine 74) with efficient and controllable oxidation of thioether 74) to sulfoxide 75) by IBX/H2O as the key step (Supplementary Figures S28,S29) (Li et al., 2014). S. Silva and co-authors by a fast, mild, atom-efficient protocol involving sequential one-pot IBX oxidation of MoritaBaylisHillman (MBH) adducts and catalyst-free conjugate addition of indolizine derivatives 65) as nucleophiles (Supplementary Figure S24) (Silva et al., 2020). These are popularly employed for CH functionalization (Kandimalla et al., 2019), bifunctionalization of olefins and cyclopropane (Banik et al., 2017; Muiz et al., 2017), and oxidative cyclizations (Chi et al., 2014; Xing et al., 2019; Zhen et al., 2019). 52, 44814484. Please enable it to take advantage of the complete set of features! Narendar Reddy Gade et al. They employed IBX as a metal-free oxidant in acetonitrile at ambient temperatures. Oxidant-Switchable Selective Synthesis of 2-Aminobenzimidazoles via C-H Amination/Acetoxylation of Guanidines. High regioselectivity was observed in the product formation. Two equivalents of IBX in EtOAc under reflux conditions provided ketones 80). Org. Several antioxidants and anti-influenza moieties containing pyrogallol 44) and catechol structures were made by Bruno. doi:10.1016/j.tetlet.2012.12.127. The protocol includes a proline-catalyzed direct Mannich reactioncyclization sequence between the in situ-generated aryl/heteroaryl/indolyl-imines and succinaldehyde (29). Authors noticed that in the absence of -CD, these reactions did not result in satisfactory yields of the aromatized products. RK (Foreign Visiting Professor-Edital N.03/2020) thanks the PROPESP/FURG, Rio Grande-RS, for visiting professorship. Chaojie Li and co-authors in an interesting research communication described a metal-free, eco-friendly, and operationally simple approach for the semisynthesis of sophocarpine 73) from matrine 72) in 91% yield, via the formation of 14-phenyl sulfinyl matrine 74) with efficient and controllable oxidation of thioether 74) to sulfoxide 75) by IBX/H2O as the key step (Supplementary Figures S28,S29) (Li et al., 2014). About ScienceDirect 21, 19891993. The aliphatic and heteroaromatic substituents at C 1) also did not hinder the reaction. 2-Aryl benzoxazoles 68) were obtained by a simple protocol by the IBX oxidation of phenolic Schiffs bases (2d) in the presence of 4Ao molecular sieves as described by Fei Chen et al. Gonzlez-Zamora E., Islas-Jcome A., Gutirrez-Carrillo A., Garca-Garibay M. (2014). conditions, use of (2013). The protocol covers a broad range of substrates with alkene, arene, and heteroarene functionalities. l Unauthorized use of these marks is strictly prohibited. The reaction tolerates a wide variety of functional groups. 43, 953962. The protocol covers a broad range of . It was observed that the presence of the ester group at C 3) appeared to be important for successful aromatization. 139, 43544357. Controllable and Efficient Oxidation of Thioether by 2-iodoxybenzoic Acid (IBX) in Water: Semisynthesis of Sophocarpine. doi:10.1039/C4OB00318G, Gade, N. R., Devendram, V., Pal, M., and Iqbal, J. Authors carried out these reactions successfully involving substrates from aromatic (118), heteroaromatic, and benzylic thioamides. Unauthorized use of these marks is strictly prohibited. Several oxidants including IBX, NBS, urea-hydrogen peroxide (UHP), tert-butyl hydroperoxide, m-chloroperoxybenzoic acid, and benzoyl peroxide were evaluated in the optimization process. The protocol has been applied for the synthesis of the antitumor and antibiotic precursor benzocarbazoledione 11). 5 Articles, This article is part of the Research Topic, Applications of IBX in the Synthesis of Heterocycles, https://doi.org/10.3389/fchem.2022.841751, https://www.frontiersin.org/articles/10.3389/fchem.2022.841751/full#supplementary-material. These moieties represent different and divergent classes of molecules such as drugs, amino acids, and dye stuffs; a large number of heterocyclic compounds are known in the literature and are being synthesized regularly. 2-Iodoxybenzoic acid (IBX) is the most important representative of pentavalent iodine compounds, apart from DMP (Hartman and Mayer, 1983). doi:10.1021/acs.joc.0c00189, Singh, A., Mir, N. A., Choudhary, S., Singh, D., Sharma, P., Kant, R., et al. 8600 Rockville Pike DMP and its precurser o-iodoxybenzoic acid (IBX) are potentially heat and shock sensitive and should be handled with appropriate care. After initial studies, authors observed that the reaction proceeded well in the presence of 1.2 eq. The electron-donating groups at C 1) afforded higher yields. Rev. Before Willgerodt, C. (1886). FOIA Chem. RSC Adv. An official website of the United States government. Kandimalla S. R., Parvathaneni S. P., Sabitha G., Subba Reddy B. V. (20192019). These moieties represent different and divergent classes of molecules such as drugs, amino acids, and dye stuffs; a large number of heterocyclic compounds are known in the literature and are being synthesized regularly. 55, 44364454. Full oxidation to carboxylic acids Narendar Reddy Gade et al. (2015). An official website of the United States government. 8600 Rockville Pike ScienceDirect is a registered trademark of Elsevier B.V. (2011). IBX DMSO, THF, 2 h, 20 C 65% HO HO OPMB OTBDPS O OTBDPS Ref. Unable to load your collection due to an error, Unable to load your delegates due to an error. MeSH Recently, the use of the hypervalent iodine reagent 1hydroxy1,2benziodoxol3(1H )one 1oxide (IBX) for the oxidation of primary alcohols and aldehydes to carboxylic acids was described.During the synthesis of these carboxylic acids the corresponding Nhydroxysuccinimide esters were formed as intermediate products, but their isolation as main reaction products was not successful. Selective and Efficient Oxidative Modifications of Flavonoids with 2-iodoxybenzoic Acid (IBX). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. Frontiers | IBX-Mediated Organic Transformations in Heterocyclic Selective and Efficient Oxidative Modifications of Flavonoids with 2-iodoxybenzoic Acid (IBX), Synthesis of Highly Substituted Pyrroles via a Multimetal-Catalyzed RearrangementCondensationCyclization Domino Approach. National Library of Medicine A mechanism was proposed for the IBX-supported cyclo-desulfurization of acylthiosemicarbazides. Catalytic 1,3-Difunctionalization via Oxidative C-C Bond Activation. An interesting rapid and efficient protocol was presented by Alejandro Islas-Jacome and co-authors for a series of four novel nuevamine aza analogs containing the isoindolo [1,2-a] isoquinoline 56) skeleton (Supplementary Figure S21) (Gonzlez-Zamora et al., 2014). A plausible mechanism for the acid-catalyzed oxidation of alcohols with IBX was explained. These difficult oxidations include: Transformation of 1,2-diols into a-dicarbonyl compounds with no oxidative breakage of a C-C bond.3'83 Oxidation of 1,4-diols to lactols with no over-oxidation to lactones.84 also thanks the CNPq-TWAS fellowship.. or 2 equiv. Tetrahedron Lett. Catalytic Enantioselective ,,-Trioxygenation. Excepting these two compounds, other hydroxy flavones 90) and flavanones 84) produced aromatic o-hydroxylated products in both the series. 115, 650682. sharing sensitive information, make sure youre on a federal Following the same synthetic strategy, Mannich substrates related to pyridine 38) and pyrazine ring systems were also investigated successfully to access highly diverse cyclic compounds imidazo [1,2-a]pyridines (39) and imidazo [1,2-a]pyrazines (40) with moderate to good yields (Supplementary Figure S17). Cheng-Kun Lin and Ta-Jung Lu reported a simple and practical approach for the IBX-assisted oxidation of primary aliphatic (77), benzylic (77a), and allylic alcohols, in the presence of stoichiometric quantity of acetic acid. 116, 33283435. Remarkably, the carbonate opening delivered exclusively (E)-olefin and no over-oxidation of -hydroxy was observed. 5b IBX performs the selective oxidation of a primary alcohol, leading to a hydroxyaldehyde that is isolated as a lactol that, interestingly, does not suVer a further oxidation to a lactone. Catalyst-Free Conjugate Addition of Indolizines to In Situ-Generated Oxidized Morita-Baylis-Hillman Adducts. Electrophilic Trifluoromethylation by Use of Hypervalent Iodine Reagents, A Simple Protocol for the Synthesis of 2-arylbenzoxazoles by Oxidation with O-Iodoxybenzoic Acid (IBX) and its Application in the Synthesis of Arylbenzoxazole-Containing Amino Acids. Xing, L., Zhang, Y., Li, B., and Du, Y. IBX-mediated oxidation of primary alcohols and aldehydes to form Chem. Authors also investigated on relative nucleophilicity of indolizines/indoles 67) and concluded that the indolizine skeleton 67) appeared to be a superior nucleophile in the present reaction conditions. Highly functionalized indolizine scaffolds 64) were produced by Thiago. The approach was also extended to include various allylic alcohols 17). The site is secure. S. Silva and co-authors by a fast, mild, atom-efficient protocol involving sequential one-pot IBX oxidation of MoritaBaylisHillman (MBH) adducts and catalyst-free conjugate addition of indolizine derivatives 65) as nucleophiles (Supplementary Figure S24) (Silva et al., 2020). A broad range of propargyl vinyl ethers 3) was used effectively. Accessibility The protocol covers a broad range of substrates with alkene, arene, and heteroarene functionalities. Various amino groups on the side chain, such as NHCbZ, NHBoc, and N3 were tolerated, and N-unprotected substrate did not give the product. Kumar D., Pilania M., Arun V., Mishra B. 2019 Feb 20;17(8):2212-2222. doi: 10.1039/c8ob03128b. A broad range of 2-substituted nicotinic acid derivatives was made by widening the substrate scope to aryl/heteroaryl/benzyl/cinnamoyl/aliphatic -enamino esters 16a). 2021 Oct 20;26(21):6350. doi: 10.3390/molecules26216350. IBX-mediated Oxidation of Unactivated Cyclic Amines: Application in Highly Diastereoselective Oxidative Ugi-type and Aza-Friedel-Crafts Reactions.
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