- Catalytic Asymmetric Allylic Substitution with Copper(I) Homoenolates Generated from Cyclopropanols
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By using copper(I) homoenolates as nucleophiles, which are generated through the ring-opening of 1-substituted cyclopropane-1-ols, a catalytic asymmetric allylic substitution with allyl phosphates is achieved in high to excellent yields with high enantioselectivity. Both 1-substituted cyclopropane-1-ols and allylic phosphates enjoy broad substrate scopes. Remarkably, various functional groups, such as ether, ester, tosylate, imide, alcohol, nitro, and carbamate are well tolerated. Moreover, the present method is nicely extended to the asymmetric construction of quaternary carbon centers. Some control experiments argue against a radical-based reaction mechanism and a catalytic cycle based on a two-electron process is proposed. Finally, the synthetic utilities of the product are showcased by means of the transformations of the terminal olefin group and the ketone group.
- Shi, Chang-Yun,Yin, Liang,Zhang, Qi,Zhou, Si-Wei
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supporting information
p. 26351 - 26356
(2021/11/09)
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- Rhodium(III)-Catalyzed Oxidative Cyclization of Oxazolines with Cyclopropanols: Synthesis of Isoindolinones
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The synthesis of C3-substituted isoindolin-1-ones from oxazolines and cyclopropanols has been achieved with oxazoline as a bifunctional nucleophilic directing group. The reaction proceeds by the cleavage of three chemical bonds and allows the formation of three new chemical bonds, a C-N bond, a C-C bond, and a C-O bond, in a single step.
- Liu, Jidan,Yang, Zhenke,Jiang, Jinyuan,Zeng, Qiaohai,Zheng, Liyao,Liu, Zhao-Qing
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supporting information
p. 5927 - 5931
(2021/07/31)
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- Iron-Catalyzed Ring-Opening Reactions of Cyclopropanols with Alkenes and TBHP: Synthesis of 5-Oxo Peroxides
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The ring opening of cyclopropanols is rarely used in multicomponent reactions. Herein we report the three-component reaction of cyclopropanols with alkenes and tert-butyl hydroperoxide (TBHP) catalyzed by an iron catalyst. This protocol enables the incorporation of both the β-carbonyl fragment and a peroxy unit across the C=C double bond regioselectively, thus allowing an efficient, facile access to 5-oxo peroxides. Modification of the biologically active molecules and various downstream derivatizations of the peroxides are also demonstrated.
- Lou, Chenhao,Wang, Xin,Lv, Leiyang,Li, Zhiping
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supporting information
p. 7608 - 7612
(2021/10/02)
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- The Cyclopropane Ring as a Reporter of Radical Leaving-Group Reactivity for Ni-Catalyzed C(sp3)-O Arylation
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The ability to understand and predict reactivity is essential for the development of new reactions. In the context of Ni-catalyzed C(sp3)-O functionalization, we have developed a unique strategy employing activated cyclopropanols to aid the design and optimization of a redox-active leaving group for C(sp3)-O arylation. In this chemistry, the cyclopropane ring acts as a reporter of leaving-group reactivity, since the ring-opened product is obtained under polar (2e) conditions, and the ring-closed product is obtained under radical (1e) conditions. Mechanistic studies demonstrate that the optimal leaving group is redox-active and are consistent with a Ni(I)/Ni(III) catalytic cycle. The optimized reaction conditions are also used to synthesize a number of arylcyclopropanes, which are valuable pharmaceutical motifs.
- Mills, L. Reginald,Monteith, John J.,Dos Passos Gomes, Gabriel,Aspuru-Guzik, Alán,Rousseaux, Sophie A. L.
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supporting information
p. 13246 - 13254
(2020/09/01)
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- Aryl Pyrazoles from Photocatalytic Cycloadditions of Arenediazonium
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A photocatalytic synthesis of 1,5-diaryl pyrazoles from arenediazoniums and arylcyclopropanols is reported. The reaction proceeded under mild conditions (rt, 20 min) with catalytic [Ru(bpy)3]2+ under blue-light irradiation and exhibited compatibility with several functional groups (e.g., I, SF5, SO2NH2, N3, CN) and perfect levels of regiocontrol. Mechanistic studies (luminescence spectroscopy, CV, DFT, radical trapping, quantum yield determination) documented an initial oxidative quenching of the excited photocatalyst and the operation of a radical-chain mechanism.
- Cardinale, Luana,Neumeier, Michael,Majek, Michal,Jacobi Von Wangelin, Axel
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supporting information
p. 7219 - 7224
(2020/10/02)
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- Copper-mediated tandem ring-opening/cyclization reactions of cyclopropanols with aryldiazonium salts: Synthesis of: N -arylpyrazoles
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A general method for the synthesis of structurally diverse N-arylpyrazoles from readily available cyclopropanols and aryldiazonium salts is disclosed. The reaction was conducted at room temperature within minutes with a broad substrate scope and excellent regioselectivity.
- Liu, Jidan,Xu, Erjie,Jiang, Jinyuan,Huang, Zeng,Zheng, Liyao,Liu, Zhao-Qing
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supporting information
p. 2202 - 2205
(2020/02/26)
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- Metal-Free Direct C–H β-Carbonyl Alkylation of Heteroarenes with Cyclopropanols Mediated by K2S2O8
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Direct C–H β-carbonyl alkylation of heteroarenes under metal-, acid- and photo-catalyst free conditions has been achieved. A wide scope of substrates, such as various substituted quinolines and isoquinolines, pyridines, pyridazine, benzo[d]thiazole and phenanthroline, underwent the β-carbonyl alkylation efficiently via K2S2O8-mediated ring-opening of cyclopropanols. The corresponding β-heteroarylated ketones were obtained in moderate to excellent yields and gram-scale experiments further demonstrated the practicality of this synthetic protocol. The readily available reagents, mild and environmentally benign conditions make the method extremely attractive. The reaction mechanism is also proposed.
- Liu, Qiang,Wang, Qiang,Xie, Guanqun,Fang, Zeyang,Ding, Shujiang,Wang, Xiaoxia
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supporting information
p. 2600 - 2604
(2020/05/05)
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- Ni-Catalyzed Denitrogenative Cross-Coupling of Benzotriazinones and Cyclopropanols: An Easy Access to Functionalized β-Aryl Ketones
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A novel Ni-catalyzed denitrogenative cross-coupling between benzotriazinones and cyclopropanols is reported herein. This neoteric reactivity allows for the convenient synthesis of β-(o-amido)aryl ketones from readily available starting materials with good yields (up to 93percent) and general substrate scope.
- Li, Jincan,Zheng, Yan,Huang, Mingxian,Li, Wanfang
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supporting information
p. 5020 - 5024
(2020/07/03)
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- Synthesizing method for 4-cyclopropyl biphenyl fluorine-containing compound
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The invention discloses a synthesizing method for 4-cyclopropyl biphenyl fluorine-containing compound. The synthesizing method comprises the following steps: performing Grignard reaction to generate aGrignard reagent of p-chloride halogen benzene by taking the p-chloride halogen benzene as an initial raw material; performing a coupling reaction with cyclopropanone to generate cyclopropanol chlorobenzene; performing a dewatering reaction to generate cyclopropanyl chlorobenzene; generating 4-cyclopropanyl phenylboric acid by a one-pot method; performing the coupling reaction with fluorine-containing benzene halide to generate a fluorine-containing 4-cyclopropanyl biphenyl compound; performing a hydrogenating reaction to obtain the 4-cyclopropyl biphenyl fluorine-containing compound. The synthesizing method has the characteristics of high conversion rate, low cost, safe and stable process, short reaction steps, high yield, environment-friendly process route and little pollutant emission.
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Paragraph 0019-0021
(2020/09/20)
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- Visible-Light-Induced Alkoxyl Radical Generation Enables Selective C(sp3)-C(sp3) Bond Cleavage and Functionalizations
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The alkoxyl radical is an important reactive intermediate in mechanistic studies and organic synthesis; however, its current generation from alcohol oxidation heavily relies on transition metal activation under strong oxidative conditions. Here we report the first visible-light-induced alcohol oxidation to generate alkoxyl radicals by cyclic iodine(III) reagent catalysis under mild reaction conditions. The β-fragmentation of alkoxyl radicals enables selective C(sp3)-C(sp3) bond cleavage and alkynylation/alkenylation reactions with various strained cycloalkanols, and for the first time with linear alcohols.
- Jia, Kunfang,Zhang, Fuyuan,Huang, Hanchu,Chen, Yiyun
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supporting information
p. 1514 - 1517
(2016/02/20)
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- Copper-catalysed ring-opening trifluoromethylation of cyclopropanols
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A copper-catalysed ring-opening trifluoromethylation reaction of cyclopropanols has been developed. Various β-trifluoromethyl ketones are obtained in good to excellent yields under mild reaction conditions. The present method also exhibits good functional-group compatibility. The mechanism of this new ring-opening trifluoromethylation reaction was investigated by radical trapping reactions.
- He, Xia-Ping,Shu, Yong-Jin,Dai, Jian-Jun,Zhang, Wen-Man,Feng, Yi-Si,Xu, Hua-Jian
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supporting information
p. 7159 - 7163
(2015/07/01)
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- γ-carbonyl quinones: Radical strategy for the synthesis of evelynin and its analogues by C-H activation of quinones using cyclopropanols
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Cyclopropanols, on oxidative ring opening with AgNO3-K 2S2O8 in DCM-H2O at room temperature and under open flask conditions, produced β-keto radicals which were successfully added to quinones to furni
- Ilangovan, Andivelu,Saravanakumar, Shanmugasundar,Malayappasamy, Subramani
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supporting information
p. 4968 - 4971
(2013/10/22)
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