- White-light emission from a structurally simple hydrazone
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Two hydrazones featuring a unique excitation wavelength-dependent dual fluorescence emission have been developed. The mixing extent of the two emission bands can be modulated by tuning the excitation wavelength, resulting in multicolor and even white light emission from structurally simple hydrazones.
- Shao, Baihao,Stankewitz, Nell,Morris, Jacob A.,Liptak, Matthew D.,Aprahamian, Ivan
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- Copper-Catalyzed Selective Pyrrole Functionalization by Carbene Transfer Reaction
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1H-Pyrroles can be directly functionalized by means of the incorporation of carbene groups from diazo compounds, in a process catalyzed by TpxCu complexes (Tpx=hydrotrispyrazolylborate ligand). The reactions take place with a complete selectivity toward the formal insertion of the carbene into the Cα?H bond, leading to alkylated pyrroles, with no modification of the Cβ?H, N?H or C=C bonds of the pyrrole unit. Alkyl substituents at C-ring as well as alkyl, aryl, allyl or alkyne substitution at N atom are tolerated, the strategy affording 20 new pyrrole derivatives. The observance of partial deuteration at the methylene group when the reaction is carried out with added D2O serves to discard the direct insertion of the carbene group into the Csp2?H bond, the alternative electrophilic attack to the pyrrole ring being feasible. (Figure presented.).
- Rodríguez, Anabel M.,Molina, Francisco,Díaz-Requejo, M. Mar,Pérez, Pedro J.
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- Semi-Synthesis of C-Ring Cyclopropyl Analogues of Fraxinellone and Their Insecticidal Activity against Mythimna separata Walker
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Fraxinellone (1) is a naturally occurring degraded limonoid isolated from Meliaceae and Rutaceae plants. As a potential natural-product-based insecticidal agent, fraxinellone has been structurally modified to improve its activity. Furan ring of fraxinellone is critical in exhibiting its insecticidal activity, but with few modifications. Herein, C-ring-modified cyclopropyl analogues were semi-synthesized by Rh(II)-catalyzed cyclopropanation. The structures of the target compounds were well characterized by NMR and HRMS. The precise three-dimensional structural information of 3a was established by X-ray crystallography. Their insecticidal activity was evaluated against Mythimna separata Walker by a leaf-dipping method. Compound 3c exhibited stronger insecticidal activity than 1 and toosendanin against M. separata with teratogenic symptoms during the different periods, implying that cyclopropanation of the furan ring could strengthen the insecticidal activity of fraxinellone.
- Dong, Qing-Miao,Tang, Jiang-Jiang,Wang, Min-Ran,Yang, Xiao-Jun
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- Regioselective One-Pot Synthesis of Triptycenes via Triple-Cycloadditions of Arynes to Ynolates
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We developed the novel one-pot synthetic method of substituted triptycenes by the reaction of ynolates and arynes. This four-step process involves three cycloadditions and electrocyclic ring opening of the strained Dewar anthracene. Each of the three related but structurally distinct classes of nucleophiles (ynolate, enolate, and anthracenolate) reacts with o-benzyne in the same predictable manner controlled by chelation and negative hyperconjugation. The resulting functionalized C3-symmetrical triptycenes hold promise in the design of functional materials.
- Umezu, Satoshi,dos Passos Gomes, Gabriel,Yoshinaga, Tatsuro,Sakae, Mikei,Matsumoto, Kenji,Iwata, Takayuki,Alabugin, Igor,Shindo, Mitsuru
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- Synthesis of Functionalized Silsesquioxane Nanomaterials by Rhodium-Catalyzed Carbene Insertion into Si?H Bonds
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We report carbene insertion into Si?H bonds of polyhedral oligomeric silsesquioxanes (POSS) for the synthesis of highly functionalized siloxane nanomaterials. Dirhodium(II) carboxylates catalyze insertion of aryl-diazoacetates as carbene precursors to afford POSS structures containing both ester and aryl groups as orthogonal functional handles for further derivatization of POSS materials. Four diverse and structurally varied silsesquioxane core scaffolds with one, three, or eight Si?H bonds were evaluated with diazo reactants to produce a total of 20 new POSS compounds. Novel diazo compounds containing a fluorinated octyl group and boron-dipyrromethene (BODIPY) chromophore demonstrate the use of highly functionalized substrates. Transformations of aryl(ester)-functionalized POSS compounds derived from this method are demonstrated, including ester hydrolysis and Suzuki–Miyaura cross-coupling.
- Franz, Annaliese K.,Jagannathan, Jake R.,Targos, Karina
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supporting information
(2021/11/27)
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- All-Carbon Tetrasubstituted Olefins Synthesis from Diazo Compounds and Iodonium Ylides under Blue LED Irradiation
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A route for the construction of all-carbon tetra-substituted olefins through visible-light promoted coupling of diazo compounds with iodonium ylides was developed. A wide range of all-carbon tetra-substituted olefins was obtained in moderate to good yields. The synthetic values of the current method were further approved by the synthesis of natural isolates modified alkenes and the successful transformation of final olefins into important heterocycles. (Figure presented.).
- Zhao, Yan-Rui,Li, Lei,Xu, Guo-Yong,Xuan, Jun
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supporting information
p. 506 - 511
(2021/12/08)
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- Visible-light-promoted selective: O -alkylation of 2-pyridones with α-aryldiazoacetates
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A visible-light-promoted O-H insertion reaction between 2-pyridones and α-aryldiazoacetates has been developed. Upon visible light irradiation, the reaction proceeds smoothly under mild and catalyst-free conditions. A wide scope of 2-pyridones and α-aryldiazoacetates are well tolerated, and various O-alkylated 2-pyridones are obtained with perfect selectivity and good functional group tolerance. A photoinduced radical process is probably responsible for the excellent selectivity. This journal is
- Yang, Jingya,Wang, Ganggang,Zhou, Hongyan,Li, Zhifeng,Ma, Ben,Song, Menghui,Sun, Rongxia,Huo, Congde
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supporting information
p. 394 - 398
(2021/01/29)
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- Divergent Synthesis of Aziridine and Imidazolidine Frameworks under Blue LED Irradiation
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We develop a visible light-promoted divergent cycloaddition of α-diazo esters with hexahydro-1,3,5-triazines, leading to a series of aziridine and imidazolidine frameworks in average good yield, by simply changing the reaction media used. It is noteworthy that the reaction occurs under sole visible light irradiation without the need for exogenous photoredox catalysts. More significantly, a reasonable reaction mechanism was proposed on the basis of the control experiments and density functional theory calculation results.
- Cheng, Xiao,Cai, Bao-Gui,Mao, Hui,Lu, Juan,Li, Lei,Wang, Kun,Xuan, Jun
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supporting information
p. 4109 - 4114
(2021/05/26)
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- Visible-Light-Promoted Polysubstituted Olefins Synthesis Involving Sulfur Ylides as Carbene Trapping Reagents
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A blue-light-emitting diode (LED) promoted coupling of aryl diazoacetates with sulfur ylides is described. This protocol features mild conditions, good functional group tolerance, and broad substrate scope for both aryl diazoacetates with sulfur ylides. Under optimal reaction conditions, a wide range of trisubstituted olefins is obtained in moderate to good yield, which can be further transferred to other biologically important heterocycles after a two-step simple operation.
- Ye, Cong,Cai, Bao-Gui,Lu, Juan,Cheng, Xiao,Li, Lei,Pan, Zhong-Wen,Xuan, Jun
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p. 1012 - 1022
(2021/01/09)
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- Tropylium-Catalyzed O-H Insertion Reactions of Diazoalkanes with Carboxylic Acids
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Herein, we describe the application of a nonbenzenoid aromatic carbocation, namely tropylium, as an organic Lewis acid catalyst in O-H functionalization reactions of diazoalkanes with benzoic acids. The newly developed protocol is applicable to a wide range of diazoalkane and carboxylic acid substrates with excellent efficiency (43 examples, up to 99% yield).
- Empel, Claire,Nguyen, Thanh Vinh,Koenigs, Rene M.
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supporting information
p. 548 - 553
(2021/01/26)
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- Dirhodium(II)/Xantphos-Catalyzed Relay Carbene Insertion and Allylic Alkylation Process: Reaction Development and Mechanistic Insights
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Although dirhodium-catalyzed multicomponent reactions of diazo compounds, nucleophiles and electrophiles have achieved great advance in organic synthesis, the introduction of allylic moiety as the third component via allylic metal intermediate remains a formidable challenge in this area. Herein, an attractive three-component reaction of readily accessible amines, diazo compounds, and allylic compounds enabled by a novel dirhodium(II)/Xantphos catalysis is disclosed, affording various architecturally complex and functionally diverse α-quaternary α-amino acid derivatives in good yields with high atom and step economy. Mechanistic studies indicate that the transformation is achieved through a relay dirhodium(II)-catalyzed carbene insertion and allylic alkylation process, in which the catalytic properties of dirhodium are effectively modified by the coordination with Xantphos, leading to good activity in the catalytic allylic alkylation process.
- Liang, Xinyi,Lu, Bin,Peng, Qian,Wang, Xiaoming,Wang, Zijian,Zhang, Jinyu
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supporting information
p. 11799 - 11810
(2021/08/16)
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- Visible light and base promoted O-H insertion/cyclization of para-quinone methides with aryl diazoacetates: An approach to 2,3-dihydrobenzofuran derivatives
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A visible light and base promoted O-H insertion/cyclization of para-quinone methides with aryl diazoacetates is developed. This one-pot two step reaction offers a mild and efficient approach for the synthesis of biologically important 2,3-dihydrobenzofuran derivatives in good yields and moderate diastereoselectivities.
- Zhou, Shuangjing,Cai, Baogui,Hu, Chuxia,Cheng, Xu,Li, Lei,Xuan, Jun
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supporting information
p. 2577 - 2581
(2021/03/22)
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- Erratum: Oxazaborolidinium Ion-Catalyzed Cyclopropanation of α-Substituted Acroleins: Enantioselective Synthesis of Cyclopropanes Bearing Two Chiral Quaternary Centers (J. Am. Chem. Soc. (2011) 133:51 (20708?20711) DOI: 10.1021/ja209270e)
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Pages 20709 and 20710. In the published version of the paper, the trans:cis ratios of 2w and 2x were reversed. The revised results were confirmed by NOE experiments and comparison of the optical rotation data with reported values after transformation. The
- Gao, Lizhu,Hwang, Geum-Sook,Ryu, Do Hyun
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supporting information
p. 6021 - 6022
(2021/05/13)
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- Copper on charcoal: Cu0nanoparticle catalysed aerobic oxidation of α-diazo esters
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By using a charcoal supported nano Cu0catalyst (Cu/C), a highly efficient oxidation of α-diazo esters to α-ketoesters with molecular oxygen as the sole oxidant has been developed. In the presence of the Cu/C catalyst, 2-aryl-α-diazo esters with both electron-donating and electron-withdrawing groups can be oxidized to the corresponding α-ketoesters efficiently. Furthermore, this Cu/C catalyst can catalyse the reaction of aryl α-diazo ester with water to form aryl ketoester, 2-aryl-2-hydroxyl acetate ester and 2-aryl acetate ester. In this case, water is split by α-diazo ester, and the diazo group is displaced by the oxygen or hydrogen atom in water. Mechanistic investigation showed that the reaction of α-diazo ester with oxygen proceeds through a radical pathway. In the presence of 2,2,6,6-tetramethyl piperidine nitrogen oxide, the reaction of α-diazo ester with oxygen is dramatically inhibited. Furthermore, the reaction of α-diazo ester with water is investigated by an isotopic tracer method, and GCMS detection showed that a disproportionation reaction occurred between α-diazo ester and water.
- Chu, Changhu,Dong, Wenwen,Lin, Jia,Teng, Jiangge,Wang, Zhiwei,Zhao, Rong
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p. 6120 - 6126
(2021/07/21)
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- Photoinduced Diverse Reactivity of Diazo Compounds with Nitrosoarenes
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A diverse reactivity of diazo compounds with nitrosoarene in an oxygen-transfer process and a formal [2 + 2] cycloaddition is reported. Nitosoarene has been exploited as a mild oxygen source to oxidize an in situ generated carbene intermediate under visible-light irradiation. UV-light-mediated in situ generated ketenes react with nitosoarenes to deliver oxazetidine derivatives. These operationally simple processes exemplify a transition-metal-free and catalyst-free protocol to give structurally diverse α-ketoesters or oxazetidines.
- Roy, Sourav,Kumar, Gourav,Chatterjee, Indranil
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supporting information
p. 6709 - 6713
(2021/09/08)
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- Visible Light-Promoted Sulfoxonium Ylides Synthesis from Aryl Diazoacetates and Sulfoxides
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A visible light-promoted reaction of donor/acceptor diazoalkanes with sulfoxides towards the synthesis of synthetically useful sulfoxonium ylides was reported. The reaction occurred under sole visible light irradiation without the need of any transition-metals or additives, affording the corresponding sulfoxonium ylides in moderate to good yields. The success of late-stage modification of natural isolates or drug candidates, scale-up reaction and transformation of sulfoxonium ylides to other useful molecules further rendered the approach valuable.
- Lu, Juan,Li, Lei,He, Xiang-Kui,Xu, Guo-Yong,Xuan, Jun
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supporting information
p. 1646 - 1650
(2021/05/28)
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- Copper-Catalyzed Oxidation of Hydrazones to Diazo Compounds Using Oxygen as the Terminal Oxidant
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A mild method for accessing diazo compounds via aerobic oxidation of hydrazones is described. This catalytic transformation employs a Cu(OAc)2/pyridine catalyst and molecular oxygen from ambient air as the terminal oxidant, generating water as the sole byproduct and affording the desired diazo compounds within minutes at room temperature. A broad array of electronically diverse aryldiazo esters, ketones, and amides can be accessed. Pyridine dramatically enhances the rate of the reaction by solubilizing the copper catalyst and serving as the Br?nsted base in the turnover-limiting proton-coupled oxidation of hydrazone by copper(II). Insights gained from mechanistic studies led to expansion of the scope of this method to include diaryl hydrazones, delivering diaryl diazomethane derivatives, which cannot be accessed via established diazo transfer methods. The products of this method may be employed in rhodium carbene catalysis without isolation of the diazo intermediate to afford cyclopropane products in good yield with high enantioselectivity.
- Liu, Wenbin,Twilton, Jack,Wei, Bo,Lee, Maizie,Hopkins, Melissa N.,Bacsa, John,Stahl, Shannon S.,Davies, Huw M. L.
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p. 2676 - 2683
(2021/03/03)
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- Blue Light-Promoted N?H Insertion of Carbazoles, Pyrazoles and 1,2,3-Triazoles into Aryldiazoacetates
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Blue light irradiation of aryldiazoacetates leads to the formation of free carbenes, which can react with carbazoles, pyrazoles and 1,2,3-triazoles to afford the corresponding N?H inserted products. These reactions are performed under air and at room temperature, allowing the mild preparation of a variety of motifs found in biologically relevant targets. (Figure presented.).
- Stivanin, Mateus L.,Fernandes, Alessandra A. G.,da Silva, Amanda F.,Okada, Celso Y.,Jurberg, Igor D.
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p. 1106 - 1111
(2020/01/25)
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- Catalytic O-H bond insertion reactions using surface modified sewage sludge as a catalyst
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Developing a greener, sustainable catalyst is a very important but challenging task in organic synthesis. Herein, for the first time, we choose more economical and greener surface modified sewage sludge-derived carbonaceous materials (SW) treated by perch
- Baell, Jonathan B.,He, Yide,Huang, Fei,Huang, He,Xu, Yao,Yi, Xiangyan,Yu, Yang,Zhang, Zhipeng
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supporting information
p. 1594 - 1604
(2020/03/26)
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- Catalytic C-C coupling of diazo compounds with arylboronic acids: Using surface modified sewage sludge as catalyst
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A green, mild and efficient synthesis of diarylmethines using sewage sludge-derived carbonaceous materials (SW) by perchloric acid catalyzed coupling reactions between diazo compounds and arylboronic acids was developed. The reaction shows a high level of functional tolerance and a broad substrate scope. Furthermore, the highly selective 1,2-alkyl shift products were furnished through the sterically demanding R4, R5 migration of diazo compounds (3-diazochromanone). The structures of 1,2-shift products have been further confirmed by single-crystal X-ray analysis. Significantly, the synthesis of the core structures of darifenacin (a clinical drug for overactive bladder syndrome, OAB) and diclofensine (a stimulant drug showing antidepressant and monoamine reuptake inhibitor activity) further demonstrated the efficacy and synthetic potential of this method. This journal is
- Huang, Fei,Huang, He,Hughes, Timothy,Xie, Yuxing,Xu, Jun,Yu, Yang,Zhang, Zhipeng
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supporting information
p. 4165 - 4173
(2020/07/14)
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- Copper-catalyzed oxyvinylation of diazo compounds
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A copper(I)-catalyzed vinylation of diazo compounds with vinylbenziodoxolone reagents (VBX) as partners is reported. The transformation tolerates diverse functionalities on both reagents delivering polyfunctionalized vinylated products. The strategy was successfully extended to a three-component/intermolecular version with alcohols. The obtained products contain synthetically versatile functional groups, such as an aryl iodide, an ester, and an allylic leaving group, enabling further modification.
- Pisella, Guillaume,Gagnebin, Alec,Waser, Jerome
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supporting information
p. 3884 - 3889
(2020/05/14)
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- Copper-catalyzed carbene insertion and ester migration for the synthesis of polysubstituted pyrroles
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Copper-catalyzed carbene insertion/ester migration/cyclization of enaminones and α-diazo compounds occurred efficiently to afford 2-ester polysubstituted pyrroles under mild conditions in moderate-to-good yields. Substituent functionality was well tolerated and13C-labelled experiments demonstrated 1,2-ester migration during the reaction.
- Li, Mingrui,Sun, Yiming,Xie, Yuxing,Yu, Yang,Huang, Fei,Huang, He
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supporting information
p. 11050 - 11053
(2020/10/05)
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- Cu(I)/chiral bisoxazoline-catalyzed enantioselective sommelet-hauser rearrangement of sulfonium ylides
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Catalytic asymmetric thia-Sommelet-Hauser rearrangement of sulfonium ylides remains a great challenge due to its multistep reaction mechanism involving metal carbene formation, proton transfer, and [2,3]-sigmatropic rearrangement. In particular, the key problem of such reactions is the differentiation of the enantiotopic lone pair electrons of sulfur, which generates the sulfonium ylide intermediate bearing chirality on the sulfur atom. With a modified chiral bisoxazoline ligand, we developed a Cu(I)- catalyzed asymmetric thia-Sommelet-Hauser rearrangement with good to excellent enantioselectivities. Mechanistic studies provide insights into the details of the reaction mechanism.
- Wang, Jianbo,Li, Shu-Sen
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supporting information
p. 12343 - 12358
(2020/11/10)
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- Visible-Light-Mediated S?H Bond Insertion Reactions of Diazoalkanes with Cysteine Residues in Batch and Flow
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We describe the application of S?H bond insertion reactions of aryl diazoacetates with cysteine residues that enabled metal-free, S?H functionalization under visible-light conditions. Moreover, this process could be intensified by a continuous-flow photomicroreactor on the acceleration of the reaction (6.5 min residence time). The batch and flow protocols described were applied to obtain a wide range of functionalized cysteine derivatives and cysteine-containing dipeptides, thus providing a straightforward and general platform for their functionalizations in mild conditions. (Figure presented.).
- Chen, Lin,Cui, Yu-Sheng,Duan, Xiu,Guo, Kai,Qin, Long-Zhou,Qiu, Jiang-Kai,Sun, Qi,Yuan, Xin,Zhuang, Kai-Qiang
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supporting information
p. 5093 - 5104
(2020/09/23)
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- Supramolecularly regulated copper-bisoxazoline catalysts for the efficient insertion of carbenoid species into hydroxyl bonds
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The catalytic insertion of copper carbenoids into O-H bonds affords synthetically useful α-alkyl/aryl-α-alkoxy/aryloxy derivatives. Herein, the design, preparation and application of supramolecularly regulated copper(i) complexes of bisoxazoline ligands is reported. We have demonstrated that the catalytic performance of these systems can be modulated by the use of an external molecule (i.e.the regulation agent), which interacts with a polyethyleneoxy chain on the ligand (i.e.the regulation site)viasupramolecular interactions. This approach has been applied to an array of structurally diverse alcohols (cycloalkyl, alkyl and aryl derivatives). Moreover, we have used this methodology to synthesise advanced synthetic intermediates of biologically relevant compounds.
- Iniesta, Ester,Vidal-Ferran, Anton
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supporting information
p. 6364 - 6367
(2020/06/21)
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- Preparation of Organic Nitrates from Aryldiazoacetates and Fe(NO3)3·9H2O
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A thermal protocol is reported for the formal insertion of nitric acid into aryldiazoacetates using Fe(NO3)3·9H2O. This strategy is mild and high yielding and allows the preparation of a large variety of members of an unprecedented family of organic nitrates. The nitrate group can be also readily transformed into other functional groups and heterocyclic moieties and can possibly allow new biological explorations of untapped potential associated with their NO-releasing ability.
- Thurow, Samuel,Fernandes, Alessandra A. G.,Quevedo-Acosta, Yovanny,De Oliveira, Matheus F.,De Oliveira, Marcelo G.,Jurberg, Igor D.
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p. 6909 - 6913
(2019/09/12)
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- Practical Application of the Aqueous 'Sulfonyl-Azide-Free' (SAFE) Diazo Transfer Protocol to Less α-C-H Acidic Ketones and Esters
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The earlier described 'sulfonyl-Azide-free' ('SAFE') protocol for diazo transfer to CH-Acidic 1,3-dicarbonyl compounds (and their similarly activated congeners) has been extended to the less reactive monocarbonyl substrates, which previously required a se
- Dar'In, Dmitry,Kantin, Grigory,Krasavin, Mikhail
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p. 4284 - 4290
(2019/11/14)
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- Copper-Catalyzed Carbene Insertion into the Sulfur-Sulfur Bond of RS-SCF 2 H/SCF 3 under Mild Conditions
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A copper-catalyzed carbene insertion into the sulfur-sulfur bond of trifluoromethyl/difluoromethyl/diphenyldisulfides under mild conditions has been developed. Diverse dithioketal derivatives were synthesized in moderate to good yields in an atom-economic
- Hong, Xin,Lu, Long,Shen, Qilong
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supporting information
p. 1602 - 1606
(2019/08/07)
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- Boron-Catalyzed Azide Insertion of α-Aryl α-Diazoesters
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A challenging metal-free azide insertion of α-aryl α-diazoesters in the presence of B(C6F5)3 (5 mol %) was developed for the first time. The reaction features an easy operation, wide substrate scope, and mild conditions an
- San, Htet Htet,Wang, Chun-Ying,Zeng, Hai-Peng,Fu, Shi-Tao,Tang, Xiang-Ying,Jiang, Min
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p. 4478 - 4485
(2019/05/01)
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- Photochemical, Metal-Free Sigmatropic Rearrangement Reactions of Sulfur Ylides
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Sigmatropic rearrangement reactions constitute one of the most fundamental reactions of carbenes. While state-of-the-art synthetic methods require the use of expensive precious metal catalysts, the application of visible light for the photolysis of α-aryldiazoacetates is much less investigated and provides an operationally simple entry to carbenes under mild reaction conditions. Herein, we report on blue-light induced sigmatropic rearrangement reactions of sulfur compounds with α-aryldiazoacetates. This process, depending on the substitution pattern of the sulfide, opens up formal insertion reactions of carbenes into S?N, S?C, or C?H bonds.
- Yang, Zhen,Guo, Yujing,Koenigs, Rene M.
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supporting information
p. 6703 - 6706
(2019/05/10)
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- Rhodium(i)-catalyzed vinylation/[2 + 1] carbocyclization of 1,6-enynes with α-diazocarbonyl compounds
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A sequential Rh(i)-catalyzed vinylation/[2 + 1]carbocyclization between enynes and diazo compounds has been developed. This transformation features a wide range of enynes and acceptor/acceptor diazo compounds, providing easy access to versatile vinyl-substituted azabicyclo[3.1.0]hexanes having a broad tolerance to functional groups.
- Huang, Junmin,Hu, Xinwei,Chen, Fengjuan,Gui, Jiao,Zeng, Wei
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supporting information
p. 7042 - 7054
(2019/08/01)
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- Three-Component Synthesis of Isoquinoline Derivatives by a Relay Catalysis with a Single Rhodium(III) Catalyst
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A rhodium(III)-catalyzed one-pot three-component reaction of N-methoxybenzamide, α-diazoester, and alkyne was developed, providing an alternative way to synthesize isoquinoline derivatives. Mechanistically, it is a relay catalysis, and the reaction occurred via successive O-alkylation and C-H activation processes, both of which were promoted by the same catalyst.
- Zhou, Chao,Jiang, Jijun,Wang, Jun
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supporting information
p. 4971 - 4975
(2019/09/03)
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- 5-endo-dig Cyclization of O-Propargyl Mandelic Acid Amides towards 2,5-Dihydrofurans
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5-endo-dig cyclization of O-propargyloxyamides, obtained through a Passerini reaction mediated by boric acid and subsequent propargylation, affords 2,5-dihydrofurans in the presence of tert-butylate. The mechanism of the reaction was studied by using DFT calculations and the results were compared with the behavior of analogous N-propargylamide derivatives.
- Gaied, Lilia Ben,Fincias, Nicolas,Garrec, Julian,Ka?m, Laurent El
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p. 7656 - 7665
(2019/12/24)
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- Intrinsically Safe and Shelf-Stable Diazo-Transfer Reagent for Fast Synthesis of Diazo Compounds
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We report a crystalline compound 2-azido-4,6-dimethoxy-1,3,5-triazine (ADT) as an intrinsically safe, highly efficient, and shelf-stable diazo-transfer reagent. Because the decomposition of ADT is an endothermal process (ΔH = 30.3 kJ mol-1), ADT is intrinsically nonexplosive, as proved by thermal, friction, and impact tests. The diazo-transfer reaction based on ADT gives diazo compounds in excellent yields within several minutes at room temperature. ADT is very stable upon >1 year storage under air at room temperature.
- Xie, Shibo,Yan, Ziqiang,Li, Yuanheng,Song, Qun,Ma, Mingming
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p. 10916 - 10921
(2018/09/17)
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- Three-Component Ring-Opening Reactions of Cyclic Ethers, α-Diazo Esters, and Weak Nucleophiles under Metal-Free Conditions
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A protocol for three-component reactions of cyclic ethers, α-diazo esters, and weak nitrogen, oxygen, carbon, and sulfur nucleophiles (pKa = 2.2-14.8) to afford a variety of structurally complex α-oxyalkylated esters is reported. These reactions involve intermolecular activation of the cyclic ether (present in excess) by the α-diazo ester to form an oxonium ylide under metal-free conditions, followed by ring opening by the nucleophile.
- Lu, Lin,Chen, Chuwei,Jiang, Huanfeng,Yin, Biaolin
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p. 14385 - 14395
(2018/11/27)
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- Method for synthesizing alpha-diazoesters compound by using microwave at normal pressure
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The invention discloses a method for synthesizing an alpha-diazoesters compound by using microwave at normal pressure. An esters compound and P-toluenesulfonyl azide are used as initial raw materials,1,8-diazabicyclo[5.4.0]undec-7-ene(DBU) is used as a catalyst, the alpha-diazoesters compound can be generated in 30 minutes by virtue of a diazo transfer reaction under a microwave assisting heating condition, and the alpha-diazoesters compound can further generate a functional product. The organic reaction rate of the method is multiple times faster than the traditional heating method, the reaction efficiency is high, the operation is simple and convenient, the synthetic reaction condition is mild, the product type is rich, and the functional group is diversified.
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Paragraph 0053-0055
(2018/11/22)
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- Rh(ii)/phosphine-cocatalyzed synthesis of dithioketal derivatives from diazo compounds through simultaneous construction of two different C-S bonds
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Rhodium(ii)/phosphine-cocatalyzed bis-sulfuration of α-diazocarbonyl compounds using thiosulfonates as the sulfenylating agent, which provided two sulfur-containing moieties, was developed via simultaneous inter- and intra-molecular C-S bond formation. This novel protocol provides a rapid synthetic route to dithioketal derivatives in moderate to good yields in an atom-economic process. The transformation is proposed to proceed through phosphine ylide formation followed by S(O2)-S bond cleavage and rearrangement.
- Rao, Changqing,Mai, Shaoyu,Song, Qiuling
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supporting information
p. 5964 - 5967
(2018/06/18)
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- Boron-Catalyzed O-H Bond Insertion of α-Aryl α-Diazoesters in Water
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A catalytic, metal-free O-H bond insertion of α-diazoesters in water in the presence of B(C6F5)3·nH2O (2 mol %) was developed, affording a series of α-hydroxyesters in good to excellent yields. The reaction features easy operation and wide substrate scope, and importantly, no metal is needed as compared with the conventional methods. Significantly, this approach further expands the applications of B(C6F5)3 under water-tolerant conditions.
- San, Htet Htet,Wang, Shi-Jun,Jiang, Min,Tang, Xiang-Ying
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supporting information
p. 4672 - 4676
(2018/08/09)
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- Generating carbyne equivalents with photoredox catalysis
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Carbon has the unique ability to bind four atoms and form stable tetravalent structures that are prevalent in nature. The lack of one or two valences leads to a set of species - carbocations, carbanions, radicals and carbenes - that is fundamental to our understanding of chemical reactivity. In contrast, the carbyne - a monovalent carbon with three non-bonded electrons - is a relatively unexplored reactive intermediate; the design of reactions involving a carbyne is limited by challenges associated with controlling its extreme reactivity and the lack of efficient sources. Given the innate ability of carbynes to form three new covalent bonds sequentially, we anticipated that a catalytic method of generating carbynes or related stabilized species would allow what we term an € assembly point' disconnection approach for the construction of chiral centres. Here we describe a catalytic strategy that generates diazomethyl radicals as direct equivalents of carbyne species using visible-light photoredox catalysis. The ability of these carbyne equivalents to induce site-selective carbon-hydrogen bond cleavage in aromatic rings enables a useful diazomethylation reaction, which underpins sequencing control for the late-stage assembly-point functionalization of medically relevant agents. Our strategy provides an efficient route to libraries of potentially bioactive molecules through the installation of tailored chiral centres at carbon-hydrogen bonds, while complementing current translational late-stage functionalization processes. Furthermore, we exploit the dual radical and carbene character of the generated carbyne equivalent in the direct transformation of abundant chemical feedstocks into valuable chiral molecules.
- Wang, Zhaofeng,Herraiz, Ana G.,Del Hoyo, Ana M.,Suero, Marcos G.
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- DIAZOMETHYLATION REAGENT AND PROCESS FOR USING IT
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The present invention relates compounds useful as reagents for the diazomethylation reaction, their preparation and the use thereof as reagents in a method for the diazomethylation reaction of aromatic substrates. It relates in particular to a compound of formula (I) wherein E is an electron withdrawing group.
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Page/Page column 41
(2018/09/12)
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- Copper-Catalyzed Carbenoid Insertion Reactions of α-Diazoesters and α-Diazoketones into Si-H and S-H Bonds
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An efficient copper-catalyzed carbenoid insertion reaction of α-diazo carbonyl compounds into Si-H and S-H bonds was developed. A wide range of α-silylesters and α-thioesters was obtained in high yields (up to 98%) from α-diazoesters using 5 mol% of a simple copper(I) salt as catalyst. Using 0.05 mol% of the same catalyst, α-diazoketones led to α-silylketones in low to good yields (up to 70%).
- Keipour, Hoda,Jalba, Angela,Delage-Laurin, Léo,Ollevier, Thierry
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p. 3000 - 3010
(2017/03/23)
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- Iron-Catalyzed Carbene Insertion Reactions of α-Diazoesters into Si-H Bonds
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An efficient iron-catalyzed carbene insertion reaction of α-diazo carbonyl compounds into the Si-H bond was developed. A wide range of α-silylesters was obtained in high yields (up to 99%) from α-diazoesters using a simple iron(II) salt as catalyst.
- Keipour, Hoda,Ollevier, Thierry
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supporting information
p. 5736 - 5739
(2017/11/10)
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- Palladium-Catalyzed [5+1] Annulation of 2-(1-Arylvinyl) Anilines and α-Diazocarbonyl Compounds toward Multi-functionalized Quinolines
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A palladium-catalyzed [5+1] annulation of 2-(1-arylvinyl) anilines and α-diazocarbonyl compounds has been developed, affording a series of multi-functionalized quinolines in moderate to good yields. This procedure proceeded with the sequential insertion o
- Zhu, Jiawei,Hu, Weiming,Sun, Song,Yu, Jin-Tao,Cheng, Jiang
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supporting information
p. 3725 - 3728
(2017/09/25)
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- Ru(ii)-Pheox-catalyzed Si-H insertion reaction: construction of enantioenriched carbon and silicon centers
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We established a highly enantioselective Si-H insertion reaction to construct chiral centers at the carbon and silicon atoms, using a Ru(ii)-pheox catalyst. The catalytic asymmetric Si-H insertion reaction of α-methyl-α-diazoesters proceeded smoothly with excellent stereoinduction at both the neighboring carbon and silicon atoms (up to 99% yield and 99% ee).
- Nakagawa, Yoko,Chanthamath, Soda,Fujisawa, Ikuhide,Shibatomi, Kazutaka,Iwasa, Seiji
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supporting information
p. 3753 - 3756
(2017/04/03)
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- Cu-Mediated Trifluoromethylation of Aromatic α-Diazo Esters with the Yagupolskii–Umemoto Reagent
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Reductive trifluoromethylation of aromatic α-diazo esters at room temperature with the Yagupolskii–Umemoto reagent {[Ph2SCF3][OTf]; (2a)} in DMF in the presence of excess CuCl gave a variety of α-trifluoromethyl arylacetates in up to
- Hu, Xiao-Qian,Han, Jia-Bin,Zhang, Cheng-Pan
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supporting information
p. 324 - 331
(2017/01/24)
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- Gold-Catalyzed [2,3]-Sigmatropic Rearrangement: Reaction of Aryl Allyl Alcohols with Diazo Compounds
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A gold-catalyzed [2,3]-sigmatropic rearrangement reaction has been developed. The intermolecular rearrangement occurs between in situ generated donor-acceptor gold-carbenes and cinnamyl alcohols via tandem oxonium ylide formation. The desired rearranged product has been accomplished selectively over more conventional O-H insertion, cyclopropanation, cycloaddition, and C-H functionalization products under mild, open-air conditions. The scope of the work has been illustrated by synthesizing a new class of substrates that can be used for constructing complex molecular targets.
- Rao, Santhosh,Prabhu, Kandikere Ramaiah
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supporting information
p. 846 - 849
(2017/02/26)
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- Rh(III)-Catalyzed Regio- and Chemoselective [4 + 1]-Annulation of Azoxy Compounds with Diazoesters for the Synthesis of 2H-Indazoles: Roles of the Azoxy Oxygen Atom
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A Rh(III)-catalyzed tandem C-H alkylation/intramolecular decarboxylative cyclization of azoxy compounds with diazoesters for the synthesis of 3-acyl-2H-indazoles is disclosed. The azoxy instead of the azo group enables a distinct approach for cyclative capture, leading to a [4 + 1]-annulation rather than a classic [4 + 2] manner. The azoxy oxygen atom is traceless after annulation, and further removal from the product is not required. This reaction features a complete regioselectivity for unsymmetrical azoxybenzenes and a compatibility of monoaryldiazene oxides.
- Long, Zhen,Wang, Zhigang,Zhou, Danni,Wan, Danyang,You, Jingsong
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supporting information
p. 2777 - 2780
(2017/06/07)
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- Rhodium(II)/Chiral Phosphoric Acid-Cocatalyzed Enantioselective O–H Bond Insertion of α-Diazo Esters
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A rhodium(II)/chiral phosphoric acid system has been developed for the asymmetric catalytic insertion of α-diazo esters into the O–H bond of carboxylic acids to generate an array of synthetically useful α-hydroxy ester derivatives in good ee (up to 95% ee). Furthermore, the substrate scope could be successfully extended to a range of phenols and alcohols with high yield (up to 92%) and excellent enantioselectivity (up to 97%) under mild reaction conditions. Additionally, a density functional theory (DFT) study was performed to elucidate the reaction mechanism. (Figure presented.).
- Zhang, Yiliang,Yao, Yuan,He, Li,Liu, Yang,Shi, Lei
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supporting information
p. 2754 - 2761
(2017/08/23)
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- Rhodium- and non-metal-catalyzed approaches for the conversion of isoxazol-5-ones to 2,3-dihydro-6H-1,3-oxazin-6-ones
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Two approaches were developed for the conversion of isoxazol-5-ones to 2,3-dihydro-6H-1,3-oxazin-6-ones. The first involves dirhodium-catalyzed reaction of aryl diazoacetates, leading to rhodium carbene intermediates that undergo insertion into the N-O bo
- Jurberg, Igor D.,Davies, Huw M.L.
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supporting information
p. 5158 - 5161
(2017/11/06)
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- Preparation method of mild diazomethane derivative
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The invention discloses a preparation method of a mild diazomethane derivative. The preparation method comprises that EWG-substituted benzene sulfonyl chloride and hydrazine hydrate undergo a reaction to produce EWG-substituted benzene sulfonyl chloride, the EWG-substituted benzene sulfonyl chloride and aldehyde or ketone undergo a reaction to produce EWG-substituted benzenesulfonylhydrazone, and the EWG-substituted benzenesulfonylhydrazone, a base and an organic solvent are mixed and undergo a replacement reaction to produce a diazomethane derivative. The diazomethane derivative is not separated and purified and is further used for a tension small ring synthesis reaction and an insertion reaction. The benzene ring of benzenesulfonylhydrazone is introduced with an electron-withdrawing group EWG, and through electron effects and steric hindrance effects, the benzenesulfonyl group on the benzenesulfonylhydrazone is easily separated so that a diazomethane derivative is produced under very mild conditions and especially at the room temperature.
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Paragraph 0144; 0147
(2017/08/28)
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