- 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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- 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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- Synthesis of γ-Keto Sulfones through a Three-Component Reaction of Cyclopropanols, DABCO ? (SO2)2 and Alkyl Halides
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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.).
- Zhang, Chun,Zhang, Chao,Tang, Jie,Ye, Shengqing,Ma, Mingliang,Wu, Jie
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supporting information
p. 3109 - 3114
(2021/05/03)
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- Rh-Catalyzed cascade C-H activation/C-C cleavage/cyclization of carboxylic acids with cyclopropanols
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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.
- Wang, Siqi,Miao, Erfei,Wang, Hao,Song, Bichao,Huang, Wei,Yang, Weibo
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supporting information
p. 5929 - 5932
(2021/06/18)
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- 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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- 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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- 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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- 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
-
supporting information
p. 5020 - 5024
(2020/07/03)
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- General Synthesis of Cyclopropanols via Organometallic Addition to 1-Sulfonylcyclopropanols as Cyclopropanone Precursors
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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.
- Jang, Yujin,Lindsay, Vincent N. G.,Poteat, Christopher M.,Rivera, Roger Machín
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supporting information
(2020/09/02)
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- The reagent Et2AlX/CH2N2 in cyclopropanation of sterically hindered olefins, as well as oxygen- and nitrogen-containing unsaturated compounds
-
A transition-metal-free method of cyclopropanation of sterically hindered olefins, substituted allylic alcohols, allylamines, and vinyl silyl ethers was developed using diazomethane in the presence of organic aluminum halides.
- Ramazanov,Yaroslavova,Yaubasarov,Gil’manova,Dzhemilev
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p. 1869 - 1873
(2019/10/22)
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- Manganese-Catalyzed Ring-Opening Coupling Reactions of Cyclopropanols with Enones
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A manganese-catalyzed ring-opening coupling reaction of cyclopropanols with enones for the facile and efficient preparation of 1,6-diketones is described. A wide array of synthetically important 1,6-diketones bearing manifold functional groups are obtained with up to 93% yield. These reactions feature broad substrate scopes, environmentally benign conditions, inexpensive catalyst, and operational simplicity.
- Zhang, Yong-Hui,Zhang, Wen-Wei,Zhang, Ze-Yu,Zhao, Kai,Loh, Teck-Peng
-
supporting information
p. 5101 - 5105
(2019/07/03)
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- Ni-Catalyzed β-Alkylation of Cyclopropanol-Derived Homoenolates
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Metal homoenolates are valuable synthetic intermediates which provide access to β-functionalized ketones. In this report, we disclose a Ni-catalyzed β-alkylation reaction of cyclopropanol-derived homoenolates using redox-active N-hydroxyphthalimide (NHPI) esters as the alkylating reagents. The reaction is compatible with 1°, 2°, and 3° NHPI esters. Mechanistic studies imply radical activation of the NHPI ester and 2e β-carbon elimination occurring on the cyclopropanol.
- Mills, L. Reginald,Zhou, Cuihan,Fung, Emily,Rousseaux, Sophie A. L.
-
supporting information
p. 8805 - 8809
(2019/11/03)
-
- Manganese-Catalyzed Electrochemical Deconstructive Chlorination of Cycloalkanols via Alkoxy Radicals
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A manganese-catalyzed electrochemical deconstructive chlorination of cycloalkanols has been developed. This electrochemical method provides access to alkoxy radicals from alcohols and exhibits a broad substrate scope, with various cyclopropanols and cyclobutanols converted into synthetically useful β- and γ-chlorinated ketones (40 examples). Furthermore, the combination of recirculating flow electrochemistry and continuous inline purification was employed to access products on a gram scale.
- Allen, Benjamin D. W.,Hareram, Mishra Deepak,Seastram, Alex C.,McBride, Tom,Wirth, Thomas,Browne, Duncan L.,Morrill, Louis C.
-
supporting information
p. 9241 - 9246
(2019/11/19)
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- Visible-Light-Mediated Aerobic Oxidation of Organoboron Compounds Using in Situ Generated Hydrogen Peroxide
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A simple and general visible-light-mediated oxidation of organoboron compounds has been developed with rose bengal as the photocatalyst, substoichiometric Et3N as the electron donor, as well as air as the oxidant. This mild and metal-free protocol shows a broad substrate scope and provides a wide range of aliphatic alcohols and phenols in moderate to excellent yields. Notably, the robustness of this method is demonstrated on the stereospecific aerobic oxidation of organoboron compounds.
- Weng, Wei-Zhi,Liang, Hao,Zhang, Bo
-
supporting information
p. 4979 - 4983
(2018/08/24)
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- METALLOENZYME INHIBITOR COMPOUNDS
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Provided are compounds having HDAC6 modulating activity, and methods of treating diseases, disorders or symptoms thereof mediated by HDAC6.
- -
-
Page/Page column 137
(2018/09/28)
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- Palladium-Catalyzed Hydroalkylation of Alkynes with Cyclopropanols: Access to γ,δ-Unsaturated Ketones
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A palladium-catalyzed hydroalkylation of alkynes with cyclopropanols has been developed. This reaction provided a straightforward way to the synthesis of γ,δ-unsaturated ketones in moderate to good yields, exhibiting high atom economy and Z/E selectivity. Deuterated tri-substituted alkenes could also be expediently produced by using deuterium oxide as a co-solvent. (Figure presented.).
- Liu, Hao,Fu, Zhiyuan,Gao, Shang,Huang, Yue,Lin, Aijun,Yao, Hequan
-
supporting information
p. 3171 - 3175
(2018/08/01)
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- Enantioselective One-Pot Synthesis of α,β-Epoxy Ketones via Aerobic Oxidation of Cyclopropanols
-
An efficient, mild, and environmentally benign method was developed for the asymmetric synthesis of 2-oxyranyl ketones from easily available tertiary cyclopropanols. The one-pot protocol includes the aerobic oxidation of cyclopropanol derivatives catalyzed by Mn(III) complexes followed by the poly-l-leucine-assisted stereoselective elimination of water from the intermediate peroxides with DBU to afford the corresponding epoxy ketones in high yields and good-to-excellent enantioselectivities (up to 97%).
- Elek, Gábor Zoltán,Borovkov, Victor,Lopp, Margus,Kananovich, Dzmitry G.
-
supporting information
p. 3544 - 3547
(2017/07/17)
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- Synthesis of γ-keto sulfones by copper-catalyzed oxidative sulfonylation of tertiary cyclopropanols
-
Tertiary cyclopropanols undergo ring-opening oxidative sulfonylation to afford γ-keto sulfones when reacting with sulfinate salts in the presence of a copper(ii) acetate catalyst and an oxidant (tert-butyl hydroperoxide or atmospheric oxygen). Various fluoroalkyl, aryl and alkyl sulfinate salts are successfully employed as sulfonylation reagents, affording the corresponding sulfones in up to 94% yields. The experimental protocol is mild and tolerates a number of functionalities in the cyclopropanol substrate. The reaction proceeds via a one-pot oxidation-Michael addition mechanism and can serve as a useful addition to the existing methods for the preparation of γ-keto sulfones based on the sulfa-Michael reaction.
- Konik, Yulia A.,Elek, Gábor Zoltán,Kaabel, Sandra,J?rving, Ivar,Lopp, Margus,Kananovich, Dzmitry G.
-
supporting information
p. 8334 - 8340
(2017/10/23)
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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
-
supporting information
p. 1514 - 1517
(2016/02/20)
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- Iron- or silver-catalyzed oxidative fluorination of cyclopropanols for the synthesis of β-fluoroketones
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The FeIII- or AgI-catalyzed oxidative fluorination of cyclopropanols via radical rearrangement is disclosed. This process features a straightforward and highly effective protocol for the site-specific synthesis of β-fluoroketones and represents an expedient method for the synthesis of γ-, δ- and ε-fluoroketones. Notably, this reaction proceeds at room temperature and tolerates a diverse array of cyclopropanols.
- Ren, Shichao,Feng, Chao,Loh, Teck-Peng
-
supporting information
p. 5105 - 5109
(2015/05/13)
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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
-
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
-
supporting information
p. 4968 - 4971
(2013/10/22)
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- Exploiting the enantioselectivity of Baeyer-Villiger monooxygenases via boron oxidation
-
The enantioselective carbon-boron bond oxidation of several chiral boron-containing compounds by Baeyer-Villiger monooxygenases was evaluated. PAMO and M446G PAMO conveniently oxidized 1-phenylethyl boronate into the corresponding 1-(phenyl)ethanol (ee = 82-91%). Cyclopropyl boronic esters were also oxidized but with no enantioselectivity. β-Boryl carboxylic esters were not oxidized by any BVMOs.
- Brondani, Patricia B.,Dudek, Hanna,Reis, Joel S.,Fraaije, Marco W.,Andrade, Leandro H.
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experimental part
p. 703 - 708
(2012/09/21)
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- Stereospecific construction of chiral tertiary and quaternary carbon by nucleophilic cyclopropanation with bis(iodozincio)methane
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The reaction of a ketone having a leaving group at the aposition, such as a,bepoxy ketone or asulfonyloxy ketone, with bis(iodozincio) methane affords a zinc alkoxide of cyclopropanol. The reaction proceeds by nucleophilic addition of the dizinc to the carbonyl group and a sequential intramolecular nucleophilic substitution of the introduced iodozinciomethyl group to the adjacent electrophilic carbon that has a leaving group. When an optically active a,β-epoxy ketone or asulfonyloxy ketone is treated with the dizinc, a zinc alkoxide of cyclopropanol having a chiral tertiary or quaternary carbon in the cyclopropane ring is obtained, and the obtained zinc alkoxide of cyclopropanol acts as a chiral ho-moenolate. When it is treated with an electrophile in the presence of copper cyanide, it gives an optically active a-tertiary or -quaternary ketone that retains high optical purity.
- Nomura, Kenichi,Matsubara, Seijiro
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scheme or table
p. 147 - 152
(2010/04/23)
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- Mn(III)-mediated reactions of cyclopropanols with vinyl azides: Synthesis of pyridine and 2-azabicyclo[3.3.1]non-2-en-1-ol derivatives
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(Chemical Equation Presented) A Mn(III)-mediated divergent synthesis of substituted pyridines and 2-azabicyclo[3.3.1]non-2-en-1-ol derivatives was exploited using readily available vinyl azides and cyclopropanols with a wide range of substituents. In short, the reactions of vinyl azides with monocyclic cyclopropanol provided pyridines in the presence of Mn(acac)3 (1.7 equiv), whereas those with bicyclic cyclopropanols led to the formation of 2-azabicyclo[3.3.1]non-2-en-1-ol derivatives using a catalytic amount of Mn(acac)3. These reactions may be initiated by a radical addition of β-keto radicals, generated by the one-electron oxidation of cyclopropanols, to vinyl azides to give iminyl radicals, which would cyclize with the intramolecular carbonyl groups. In addition, versatile transformations of 2-azabicyclo[3.3.1] non-2-en-1-ol to 2-azabicyclo[3.3.1]nonane or -non-2-nen frameworks were developed.
- Wang, Yi-Feng,Chiba, Shunsuke
-
supporting information; experimental part
p. 12570 - 12572
(2010/01/30)
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- Yttrium-mediated conversion of vinyl grignard reagent to a 1,2-dimetalated ethane and its synthetic application
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A new 1,2-dimetalated ethane was generated from a vinyl Grignard reagent in the presence of yttrium(III) chloride, sodium cyclopentadienide, and diisobutylaluminum hydride (Dibal). This reagent enables the regio- and stereoselective (metaloethyl)metalation of acetylenes to produce ethylated alkenes after hydrolysis. In addition to simple hydrolysis, further carbon-carbon bond formation or functionalization at the metaloethyl group is possible, demonstrating that the yttrium-based 1,2-dimetalated ethane works as a conjunctive reagent. In addition, the reactive dicarbanionic character of this reagent effects one-pot synthesis of cyclopronanols from esters via consecutive double carbonyl addition. Copyright
- Tanaka, Ryoichi,Sanjiki, Hiroaki,Urabe, Hirokazu
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p. 2904 - 2905
(2008/09/19)
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- Preparation of zinc-homoenolate from α-sulfonyloxy ketone and bis(iodozincio)methane
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Treatment of α-sulfonyloxy ketone with bis(iodozincio)-methane gives a zinc cyclopropoxide which is formed via a nucleophilic addition of the reagent to carbonyl group followed by an intramolecular substitution reaction. Copyright
- Nomura, Kenichi,Matsubara, Seijiro
-
p. 164 - 165
(2007/10/03)
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- An efficient and general approach to β-functionalized ketones
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Figure presented The oxidation of selected anlons (N3 -, SCN-, I-, and Br-) by eeric ammonium nitrate (CAN) in the presence of substituted cyclopropyl alcohols provides a novel approach to β-functionalized ketones. The protocol has a number of advantages including short reaction times, ease of reagent handling, and mild, neutral reaction conditions. Overall, this method provides an alternative pathway to important starting materials and intermediates in organic synthesis.
- Jingliang, Jiao,Nguyen, Larry X.,Patterson, Dennis R.,Flowers II, Robert A.
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p. 1323 - 1326
(2008/01/01)
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- Mechanism of the Kulinkovich Cyclopropanol Synthesis: Transfer-Epititanation of the Alkene in Generating the Key Titanacyclopropane Intermediate
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An investigation of the Kulinkovich cyclopropanol synthesis, the interaction of esters with 2:1 or 3:1 mixtures of alkyl Grignard reagents and Ti(OiPr)4 at low temperatures, has been conducted, in order to ascertain which reactive intermediates are involved and how they are interconverted. Because of the nature of the ultimate product, one of the most obvious intermediates is the 1,1-diisopropoxy-1-titanacyclopropane stemming from the epititanation of the alkene set free from the alkyl Grignard reagent employed. A search for the formation of such a titanocycle by warming an ethereal solution of either Et2Ti(OiPr)2 or iPr 2Ti(OiPr)2 between -78 °C and +25 °C was attempted by chemical trapping with either an ester or nitrile. In this manner it was shown that such a titanocycle was formed in the case of Et2Ti(OiPr) 2 but not with iPr2Ti(OiPr)2. As to the role of two other potential intermediates, Ti(OiPr)2 and R 2Ti(OiPr)2, it was demonstrated that preformed Ti(OiPr)2 in the presence of ethylene and an ester does not form the corresponding cyclopropanol. Thus, under the reaction conditions Ti(OiPr) 2 cannot perform the direct epimetallation necessary to produce the requisite titanacyclopropane. On the other hand, either iPr 2Ti(OiPr)2 or Et2-Ti(OiPr)2 can achieve the transfer-epititanation of ethylene at low temperatures and hence with methyl benzoate yield 1-phenyl-1-cyclopropanol. In contrast, neither iPr2Ti(OiPr)2 nor Et2Ti(OiPr) 2 can at low temperatures transfer-epititanate propylene. This difference in alkene reactivity can be ascribed to steric factors operating in the proposed octahedral transition state for transfer-epimetallation. Finally, by introducing free ethylene into such Kulinkovich reaction mixtures, either by ethylene gas itself or a third equivalent of EtMgX, the isolated yields of cyclopropanols were more than doubled over those obtained with a 1:2 ratio of Ti(OiPr)4/EtMgX. From this observation one can conclude that free ethylene catalytically initiates the Kulinkovich reaction by coordinating with Et2Ti(OiPr)2 and undergoes transfer-epititanation to produce the requisite titanacyclopropane and thereby liberates ethylene, which perpetuates the reaction. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Eisch, John J.,Adeosun, Adetenu A.,Gitua, John N.
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p. 4721 - 4727
(2007/10/03)
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- Reactions of 2-substituted epichlorohydrins
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2-Substituted epichlorohydrins have been synthesized by starting with 1,2-dichloro acetone and various alkyl and aryl halides via dichlorohydrins followed by cyclization. The reactive 2-substituted epichlorohydrins were subjected to nucleophilic attacking of azide and cyanide ions to afford corresponding β-azido alcohols and α,β-unsaturated nitriles.
- Tanyeli,Demir,Akhmedov,Ozgul,Kandemir
-
p. 2967 - 2980
(2007/10/03)
-
- Alkylation-annulation of halo esters with organometallic reagent/SmI2 couple leading to cycloalkanols: A facile cyclopropanol synthesis from a 3-halo ester
-
Transformation of a 3-halo ester to cyclopropanols has been accomplished in excellent yields under mild conditions employing a coupled reagent of samarium(II) diiodide with organometallic reagents. 5- and 6-Halo esters were also transformed into cyclopentanols and cyclohexanols, respectively, in low to moderate yields. The reaction with a 4-halo ester gave 2,2-disubstituted tetrahydrofuran as a major product that resulted from double alkylation followed by cyclization; a substituted cyclobutanol was formed in poor yield.
- Fukuzawa, Shin-Ichi,Furuya, Hideki,Tsuchimoto, Teruhisa
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p. 1953 - 1960
(2007/10/03)
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- Cyclopropanization of Methyl Carboxylates with Tebbe-Type Reagents
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The methylenation reaction of methyl azulene-2-carboxylates (cf.Schemes 1 and 2) with Tebbe's or Takai's reagent is described.When the prescribed amount of Takai's reagent is applied in a four-fold excess, the corresponding cyclopropyl methyl ethers are f
- Fallahpour, Reza-Ali,Hansen, Hans-Juergen
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p. 2297 - 2302
(2007/10/02)
-
- Electron transfer in P450 mechanisms. Microsomal metabolism of cyclopropylbenzene and p-cyclopropylanisole
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The metabolism of cyclopropylbenzene (1a) and 4-cyclopropylanisole (1b) was studied using liver microsomal preparations from control, phenobarbital- and β-naphthoflavone treated rats. With all three types of microsomes 1a was metabolized by benzylic hydroxylation to give 1-phenylcyclopropanol and by aromatic hydroxylation at C-4; the former predominated by a factor of 2-4. BNF-induced microsomes also formed 2-cyclopropylphenol. No cyclopropyl ring-opened metabolites of 1a, including benzoic acid, were detected in any of the incubations. With PB-induced microsomes 1b underwent O-demethylation (90%) and benzylic hydroxylation; no other metabolites were detected. Progress curves for metabolism of 1a are markedly nonlinear after only limited conversion of substrate, suggesting the possibility that 1a, like other cyclopropyl compounds, could be a suicide substrate for one or more isozymes of P450. For both 1a and b, metabolite formation and enzyme inactivation can be explained by conventional P450 reaction mechanisms not involving electron abstraction.
- Riley,Hanzlik
-
-
- Generation of β-Carbonyl Radicals from Cyclopropanol Derivatives by the Oxidation with Manganese(III) 2-Pyridinecarboxylate and Their Reactions with Electron-Rich and -Deficient Olefins
-
Various β-carbonyl radicals are generated oxidatively from cyclopropanol derivatives by the use of manganese(III) 2-pyridinecarboxylate (Mn(pic)3).These β-carbonyl radicals react with electron-rich olefins such as conjugated silyl enol ethers, a ketene th
- Iwasawa, Nobuharu,Hayakawa, Satoshi,Funahashi, Masahiro,Isobe, Koichi,Narasaka, Koichi
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p. 819 - 827
(2007/10/02)
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- Reactions of Carbonyl Compounds with Benzyl Chloromethyl Ether of Diiodomethane in the Presence of Samarium(II) Iodide or Metallic Samarium. New Routes to 1,2-Diols, Iodohydrins and Cyclopropanols
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Carbonyl compounds react with benzyl chloromethyl ether in the presence of samarium(II) iodide to afford the corresponding addition products which, when subsequently hydrogenolysed, yield 1,2-diols.Simple aldehydes and ketones react with diiodomethane in the presence of samarium metal to give iodohydrins in good yields.Under similar reaction conditions, α-halogeno substituted ketones and aromatic 1,4-diketones are converted into cyclopropanols.These cyclopropanations have been shown to rpoceed through the initial generation of samarium enolates, followed by the Simmons-Smith type reaction.A novel transformation of esters to cyclopropanols via tandem one-carbon homologation is also described.
- Imamoto, Tsuneo,Hatajima, Toshihiko,Takiyama, Nobuyuki,Takeyama, Toshiaki,Kamiya, Yasuo,Yoshizawa, Takeshi
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p. 3127 - 3135
(2007/10/02)
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- A facile cyclopropanol synthesis from β-halo ester with Grignard reagent-samarium(II) diiodide couple
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Transformation of α,β-halo ester to the cyclopropanols by a coupled reagent of samarium(II) diiodide with Grignard reagent in tetrahydrofuran-hexamethylphosphoric triamide was very successful under mild conditions.
- Fukuzawa,Niimoto,Sakai
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p. 7691 - 7694
(2007/10/02)
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- The reaction of trialkylstannylmethyllithium with α,β-epoxy ketones and α-chloro ketones
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The reactions of trialkylstannylmethyllithium with α,β-epoxy ketones afforded mainly cyclopropanols, while α-chloro ketones afforded allyl alcohols and/or cyclopropanols, in varying amounts depending upon the molar ratio of the reagent to the substrate.
- Sato, Tadashi,Kikuchi, Toshihiro,Tsujita, Hiroshi,Kaetsu, Atsushi,Sootome, Norio,Nishida, Ken-Ichiro,Tachibana, Kazutaka,Murayama, Eigoro
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p. 3281 - 3304
(2007/10/02)
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- REACTION OF ALKYLMAGNESIUM HALIDES WITH CARBOXYLIC ESTERS IN THE PRESENCE OF TETRAISOPROPOXYTITANIUM
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The reaction of carboxylic esters with a threefold molar excess of ethylmagnesium bromide in the presence of an equimolar amount of tetraisopropoxytitanium leads to the formation of the corresponding 1-substituted 1-cyclopropanols.Propyl-, butyl-,and 2-phenylethylmagnesium bromides enter into a similar reaction, leading to 1,2-disubstituted 1-cyclopropanols.
- Kulinkovich, O.G.,Sviridov, S.V.,Vasilevskii, D.A.,Savchenko, A.I.,Pritytskaya, T.S.
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p. 250 - 253
(2007/10/02)
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- TETRAISOPROPOXYTITANIUM-CATALYZED REACTION OF ALKYLMAGNESIUM HALIDES WITH ESTERS AS A CONVENIENT METHOD FOR THE PRODUCTION OF SUBSTITUTED CYCLOPROPANOLS
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The reaction of alkylmagnesium halides with carboxylic esters at room temperature in the presence of tetraisopropoxytitanium gives good yields of the respective 1-substituted cyclopropanols.
- Kulinkovich, O. G.,Vasilevskii, D. A.,Savchenko, A. I.,Sviridov, S. V.
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p. 1249 - 1251
(2007/10/02)
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- New Formal Synthesis of (+/-)-Estrone
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(+/-)-Estrone is synthesised via Torgov's compound by an AB->ABC->ABCD route.The C-ring is constructed by a new Diels-Alder methodology and the D-ring by a novel cyclopentane annulation reaction from a cyclopropanol precursor.
- Sunder, Nurani M.,Patil, Prakash A.,Narasimhan, Nurani S.
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p. 1331 - 1334
(2007/10/02)
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- TANDEM ONE-CARBON HOMOLOGATION OF ESTERS TO CYCLOPROPANOLS
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Esters react with diiodomethane in the presence of samarium to afford 1-substituted cyclopropanols in good yields.
- Imamoto, Tsuneo,Kamiya, Yasuo,Hatajima, Toshihiko,Takahashi, Harumi
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p. 5149 - 5152
(2007/10/02)
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- DIVALENT SAMARIUM-INDUCED CYCLOPROPANATION OF LITHIUM ENOLATES. A ONE-POT SYNTHESIS OF CYCLOPROPANOLS FROM KETONES
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Lithium enolates, generated by deprotonation of ketones with lithium diisopropylamide, react with diiodomethane in the presence of SmI2 to give cyclopropanols.
- Imamoto, Tsuneo,Takiyama, Nobuyuki
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p. 1307 - 1308
(2007/10/02)
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- One-Pot Synthesis of 1-Substituted Cyclopropanols from Carboxylic Acid Chlorides
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The in situ generated chloromethyl-lithium reacts at -78 deg C to -30 deg C with different acid chlorides (2:1 molar ratio) to afford, after lithiation with lithium powder, 1-substituted cyclopropanols.
- Barluenga, Jose,Fernandez-Simon, Jose L.,Concellon, Jose M.,Yus, Miguel
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p. 584 - 586
(2007/10/02)
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- THE REACTION OF CARBONYL COMPOUNDS WITH DIIODOMETHANE IN THE PRESENCE OF SAMARIUM: NOVEL SYNTHESES OF IODOHYDRINS AND CYCLOPROPANOLS
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The iodomethylation of carbonyl compounds giving iodohydrins has been achieved under ordinary conditions by the use of diiodomethane and samarium.A novel synthesis of cyclopropanols from α-haloketones or 1,2-dibenzoylethane is also described.
- Imamoto, Tsuneo,Takeyama, Toshiaki,Koto, Hiroyasu
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p. 3243 - 3246
(2007/10/02)
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