15973-65-6Relevant academic research and scientific papers
Catalytic Asymmetric Allylic Substitution with Copper(I) Homoenolates Generated from Cyclopropanols
Shi, Chang-Yun,Yin, Liang,Zhang, Qi,Zhou, Si-Wei
supporting information, p. 26351 - 26356 (2021/11/09)
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.
Synthesis of γ-Keto Sulfones through a Three-Component Reaction of Cyclopropanols, DABCO ? (SO2)2 and Alkyl Halides
Zhang, Chun,Zhang, Chao,Tang, Jie,Ye, Shengqing,Ma, Mingliang,Wu, Jie
supporting information, p. 3109 - 3114 (2021/05/03)
A route to γ-keto sulfones through a metal-free reaction of cyclopropanols, DABCO ? (SO2)2 and alkyl halides is described. This reaction occurs under mild conditions in the absence of any catalysts, additives, or oxidants. Various functional groups including as ester, amino, methoxy, bromo, trifluoromethyl, nitro and carbonyl are tolerated well in this transformation, and the corresponding γ-keto sulfones are afforded in 35% to 95% yields. The proposed mechanism implies that this reaction proceeds through γ-keto sulfinate intermediate generated in situ, which further undergoes nucleophilic substitution with alkyl halides leading to γ-keto sulfones. (Figure presented.).
Rh-Catalyzed cascade C-H activation/C-C cleavage/cyclization of carboxylic acids with cyclopropanols
Wang, Siqi,Miao, Erfei,Wang, Hao,Song, Bichao,Huang, Wei,Yang, Weibo
supporting information, p. 5929 - 5932 (2021/06/18)
Merging both C-H and C-C activation in a tandem process is a marked challenge. A novel Rh(iii)-catalyzed C-H activation/ring opening C-C cleavage/cyclization of carboxylic acids with cyclopropanols was developed for the synthesis of 3-substituted phthalides andα,β-butenolides. This reaction displays excellent functional group tolerance with respect to both carboxylic acids and cyclopropanols and features relatively mild conditions. Remarkably, the utility of this method was highlighted by the rapid construction of bioactive compounds bearing a 3-substituted phthalide frameworkvialate-stage functionalization.
Iron-Catalyzed Ring-Opening Reactions of Cyclopropanols with Alkenes and TBHP: Synthesis of 5-Oxo Peroxides
Lou, Chenhao,Wang, Xin,Lv, Leiyang,Li, Zhiping
, p. 7608 - 7612 (2021/10/02)
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.
General Synthesis of Cyclopropanols via Organometallic Addition to 1-Sulfonylcyclopropanols as Cyclopropanone Precursors
Jang, Yujin,Lindsay, Vincent N. G.,Poteat, Christopher M.,Rivera, Roger Machín
supporting information, (2020/09/02)
The addition of organometallic reagents to ketones constitutes one of the most straightforward synthetic approaches to tertiary alcohols. However, due to the absence of a well-behaved class of cyclopropanone surrogates accessible in enantioenriched form, such a trivial synthetic disconnection has received very little attention in the literature for the formation of tertiary cyclopropanols. In this work, we report a simple and high-yielding synthesis of 1-substituted cyclopropanols via the addition of diverse organometallic reagents to 1-phenylsulfonylcyclopropanols, acting here as in situ precursors of the corresponding cyclopropanones. The transformation is shown to be amenable to sp-, sp2-, or sp3-hybridized organometallic C-nucleophiles under mild conditions, and the use of enantioenriched substrates led to highly diastereoselective additions and the formation of optically active cyclopropanols.
The Cyclopropane Ring as a Reporter of Radical Leaving-Group Reactivity for Ni-Catalyzed C(sp3)-O Arylation
Mills, L. Reginald,Monteith, John J.,Dos Passos Gomes, Gabriel,Aspuru-Guzik, Alán,Rousseaux, Sophie A. L.
supporting information, p. 13246 - 13254 (2020/09/01)
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.
Copper-mediated tandem ring-opening/cyclization reactions of cyclopropanols with aryldiazonium salts: Synthesis of: N -arylpyrazoles
Liu, Jidan,Xu, Erjie,Jiang, Jinyuan,Huang, Zeng,Zheng, Liyao,Liu, Zhao-Qing
supporting information, p. 2202 - 2205 (2020/02/26)
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.
Metal-Free Direct C–H β-Carbonyl Alkylation of Heteroarenes with Cyclopropanols Mediated by K2S2O8
Liu, Qiang,Wang, Qiang,Xie, Guanqun,Fang, Zeyang,Ding, Shujiang,Wang, Xiaoxia
supporting information, p. 2600 - 2604 (2020/05/05)
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.
Ni-Catalyzed Denitrogenative Cross-Coupling of Benzotriazinones and Cyclopropanols: An Easy Access to Functionalized β-Aryl Ketones
Li, Jincan,Zheng, Yan,Huang, Mingxian,Li, Wanfang
supporting information, p. 5020 - 5024 (2020/07/03)
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.
Aryl Pyrazoles from Photocatalytic Cycloadditions of Arenediazonium
Cardinale, Luana,Neumeier, Michael,Majek, Michal,Jacobi Von Wangelin, Axel
, p. 7219 - 7224 (2020/10/02)
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.
