- Efficient Multigram Approach to Acetylenes and CF3-ynones Starting from Dichloroalkenes Prepared by Catalytic Olefination Reaction (COR)
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A novel approach to terminal acetylenes based on catalytic olefination reaction COR of arylaldehydes to form dichloroalkenes followed by treatment with nBuLi was elaborated. This method is atom economical and displays high yields and effectivity. The corresponding alkynes can be prepared in up to 97 % yield. One pot procedure towards CF3-ynones was elaborated to provide these products in up to 87 % yield starting from dichloroalkenes.
- Muzalevskiy, Vasiliy M.,Sizova, Zoia A.,Diusenov, Arstan I.,Shastin, Alexey V.,Nenajdenko, Valentine G.
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p. 4161 - 4166
(2020/07/13)
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- Stereodivergent Synthesis of Alkenylpyridines via Pd/Cu Catalyzed C-H Alkenylation of Pyridinium Salts with Alkynes
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The first Pd/Cu catalyzed selective C2-alkenylation of pyridines with internal alkynes has been developed via the pyridinium salt activation strategy. Importantly, the configuration of the product alkenylpyridines could be tuned by the choice of the proper N-alkyl group of the pyridinium salts, thus allowing for both the Z- and E-alkenylpyridines synthesized with good regio- and stereoselectivity. A plausible mechanism was proposed based on the Hammett study and KIE experiment.
- Chen, Hua,Haiyan, Fu,Jiang, Weidong,Li, Ruixiang,Li, Shun,Li, Wenjing,Tang, Juan,Xu, Bin,Yuan, Maolin,Zheng, Xueli
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supporting information
p. 7814 - 7819
(2020/11/03)
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- Cross-coupling reactivity of 1,1-dichloroalkenes under palladium catalysis: Domino synthesis of diarylalkynes
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An efficient synthesis of diarylalkynes was achieved from the domino cross-coupling reaction of 1,1-dichloroalkenes with triarylbismuth reagents under palladium-catalyzed conditions. Under the established palladium protocol, 1,1-dichloroalkenes demonstrated hitherto unknown remarkable cross-coupling reactivity with organometallic triarylbismuth reagents to furnish functionalized diarylalkynes.
- Maddali, L. N. Rao,Meka, Suresh
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supporting information
p. 4412 - 4418
(2018/03/21)
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- A Robust One-Step Approach to Ynamides
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A robust one-step synthetic strategy for ynamide with cheap and easily available stock chemicals vinyl dichlorides and electron deficient amides as the starting material is described. In the absence of transition-metal catalyst, the reaction proceeds under mild reaction conditions in open air and thus rendering a convenient operation. This strategy is not only suitable for both terminal and internal ynamide synthesis but also amenable for large-scale preparation. Broad substrate scopes with respect to vinyl dichloride as well as electron-deficient amide were observed.
- Tu, Yongliang,Zeng, Xianzhu,Wang, Hui,Zhao, Junfeng
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supporting information
p. 280 - 283
(2018/01/17)
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- β-(Carbonatoxy)alkyl radicals: A new subset of β-(ester)alkyl radical fragmentation during copper(I)-mediated synthesis of 1,1-dichloro-1-alkenes
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A new subset of β-(ester)alkyl radicals is presented. It is the first study on the chemistry of β-(alkoxycarbonyloxy)alkyl radicals that fill the gap in the spectrum of the migrating groups in β-(ester)alkyl radical reactions. The change from less nucleofugal (acetate) group to the more nucleofugal (carbonate) group in the spectrum of the migrating group changed the reaction path from rearrangement to fragmentation. This approach has been used for the synthesis of 1,1-dichloroalkenes in high yields. The formation of dichloroalkenes was accounted by the involvement of alkene radical cation and carbonate anion pair (a CIP) as a result of heterolysis of the CO bond of the carbonate at the β-position of the β-(alkoxycarbonyloxy)alkyl radical. The alkene radical cation was trapped by nucleophilic reaction with MeOH to form methyl ester.
- Ram, Ram N.,Tittal, Ram K.
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supporting information
p. 4342 - 4345
(2014/07/22)
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- SmI2-mediated elimination reaction of trichloromethyl carbinols: A facile method to synthesize vinyl dichlorides
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Samarium diiodide-mediated elimination reaction provides a simple and general method to synthesize vinyl dichlorides from trichloromethyl carbinols directly in good to excellent yields.
- Li, Jian,Xu, Xiaoliang,Zhang, Yongmin
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p. 9349 - 9351
(2007/10/03)
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The (silylethynyl)- and the (tolylethinyl)-hydrazines 1a and 1b react with aryl isocyanates 2a-e and arylsulfonyl isocyanates 2f,g to form the corresponding substituted 3-arylimino-(or arylsulfonylimino-) 1,1,2-trimethyl-5-oxopyrazolidinium-4-ides 3a-h. The silyl group in the 4-position can be replaced by a hydrogen atom (formation of 6a-e). Heating of 6d in toluene induced the unequivocal transformation of the betaine to an isomer, the spectrocopic data of which are in concordance with those of the 4-quinolone derivative 7. Aroyl isocyanates 8 react in a [4+2]cycloaddition with 1a to furnish the 1,3-oxazin-4-ones 9a and b. The stannylated ynehydrazine 1c adds the cumulenic system of an aryl isocyanate (2d) across the Csp-Sn single bond, and trimethylstannyl N-(p-chlorophenyl)-3-(trimethylhydrazmo)propiolimidate 10 is isolated. With two molecules of 2d the hydantoin derivative 11 is formed.
- Himbert, Gerhard,Gerulat, Oliver
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p. 1196 - 1204
(2007/10/03)
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- Pyridazinone derivatives
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The present invention provides a novel pyridazinone derivative represented by the formula wherein R is a hydrogen atom or methyl, X is a halogen atom, A is an oxygen atom or a sulfur atom, and X1 is a halogen atom; a insecticidal, miticidal and fungicidal composition for agricultural and horticultural use comprising an effective amount of said pyridazinone derivative; and method for killing harmful insects, mites and bacteria comprising applying to a plant an effective amount of said pyridazinone derivative.
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