- Ligand-Controlled Regiodivergence in Nickel-Catalyzed Hydroarylation and Hydroalkenylation of Alkenyl Carboxylic Acids**
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A nickel-catalyzed regiodivergent hydroarylation and hydroalkenylation of unactivated alkenyl carboxylic acids is reported, whereby the ligand environment around the metal center dictates the regiochemical outcome. Markovnikov hydrofunctionalization products are obtained under mild ligand-free conditions, with up to 99 % yield and >20:1 selectivity. Alternatively, anti-Markovnikov products can be accessed with a novel 4,4-disubstituted Pyrox ligand in excellent yield and >20:1 selectivity. Both electronic and steric effects on the ligand contribute to the high yield and selectivity. Mechanistic studies suggest a change in the turnover-limiting and selectivity-determining step induced by the optimal ligand. DFT calculations reveal that in the anti-Markovnikov pathway, repulsion between the ligand and the alkyl group is minimized (by virtue of it being 1° versus 2°) in the rate- and regioselectivity-determining transmetalation transition state.
- Deng, Ruohan,Engle, Keary M.,Fu, Yue,Gao, Yang,Li, Zi-Qi,Liu, Peng,Tran, Van T.
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supporting information
p. 23306 - 23312
(2020/10/19)
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- Method for synthesizing 5(6)-decenoic acid
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The invention provides a method for synthesizing 5(6)-decenoic acid. Epsilon-decalactone used as a raw material undergoes a ring-opening reaction with an organic acid as a catalyst at a reaction temperature of 80-220 DEG C for 1-8 h. The method for synthesizing 5(6)-decenoic acid, using the organic acid as the catalyst, has the advantages of high catalytic activity, good selectivity, high reactionconversion rate, and realization of non-oxidation, non-carbonization and good color of the product.
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Paragraph 0017-0038
(2019/08/30)
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- A milk lactone perfume continuous compound into method (by machine translation)
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The invention belongs to the technical field of synthetic perfume, and in particular relates to a milk lactone perfume continuous compound into a method, including the role of the alkali under the condition of the aldol reaction, then by hydrogenation reaction, Baeyer - Villiger oxidation, acid continuous hydrolysis, dehydrating and gets milk lactone perfume; the aldol condensation reactions include: part of the as a footing of a cyclohexanone with a alkali mixing, heating processing, the rest [...] butyraldehyde mixture of cyclohexanone with, side drop edge added stirring, and after dropping to continue stirring, thermal insulation reaction-butyraldehyde content to 1% following the end of the reaction; static divider separating the oil, collected and recycled water; collecting oil layer after washing the processing and then transferred to the distillating still distillation recovery excessive cyclohexanone mechanically, the collection of the condensation product of the pan bottom; the invention by adding cyclohexanone in a different way, improving the yield of the aldol condensation reaction; and, of the present invention under the conditions of reaction temperature, can step from an aldol condensation product. (by machine translation)
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- In Situ Methylene Capping: A General Strategy for Efficient Stereoretentive Catalytic Olefin Metathesis. the Concept, Methodological Implications, and Applications to Synthesis of Biologically Active Compounds
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In situ methylene capping is introduced as a practical and broadly applicable strategy that can expand the scope of catalyst-controlled stereoselective olefin metathesis considerably. By incorporation of commercially available Z-butene together with robust and readily accessible Ru-based dithiolate catalysts developed in these laboratories, a large variety of transformations can be made to proceed with terminal alkenes, without the need for a priori synthesis of a stereochemically defined disubstituted olefin. Reactions thus proceed with significantly higher efficiency and Z selectivity as compared to when other Ru-, Mo-, or W-based complexes are utilized. Cross-metathesis with olefins that contain a carboxylic acid, an aldehyde, an allylic alcohol, an aryl olefin, an α substituent, or amino acid residues was carried out to generate the desired products in 47-88% yield and 90:10 to >98:2 Z:E selectivity. Transformations were equally efficient and stereoselective with a ~70:30 Z-:E-butene mixture, which is a byproduct of crude oil cracking. The in situ methylene capping strategy was used with the same Ru catechothiolate complex (no catalyst modification necessary) to perform ring-closing metathesis reactions, generating 14- to 21-membered ring macrocyclic alkenes in 40-70% yield and 96:4-98:2 Z:E selectivity; here too, reactions were more efficient and Z-selective than when the other catalyst classes are employed. The utility of the approach is highlighted by applications to efficient and stereoselective syntheses of several biologically active molecules. This includes a platelet aggregate inhibitor and two members of the prostaglandin family of compounds by catalytic cross-metathesis reactions, and a strained 14-membered ring stapled peptide by means of macrocyclic ring-closing metathesis. The approach presented herein is likely to have a notable effect on broadening the scope of olefin metathesis, as the stability of methylidene complexes is a generally debilitating issue with all types of catalyst systems. Illustrative examples of kinetically controlled E-selective cross-metathesis and macrocyclic ring-closing reactions, where E-butene serves as the methylene capping agent, are provided.
- Xu, Chaofan,Shen, Xiao,Hoveyda, Amir H.
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supporting information
p. 10919 - 10928
(2017/08/15)
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- Preparation of stereochemically pure E- and Z-alkenoic acids and their methyl esters from bicyclo[n.1.0]alkan-1-ols. Application in the synthesis of insect pheromones
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Oxidative cleavage of exo- and endo-alkyl- and hydroxyalkyl-substituted bicyclo[n.1.0]alkan-1-ols with (diacetoxy-λ3-iodanyl)benzene gave the corresponding methyl alkenoates exclusively with E or Z configuration of the double bond. This reaction was used as the key stage in the syntheses of stereoisomerically pure components of pest insect pheromones: (E)-dodec-9-en-1-yl acetate (European pine shoot moth Rhyacionia buoliana), (Z)-tetradec-11-en-1-yl acetate (European oak leafroller Tortrix viridana), and (3E,8Z,11Z)-tetradeca-3,8,11-trien-1-yl acetate (tomato leafminer Tuta absoluta).
- Zubrytski,Kananovich,Matiushenkov
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p. 813 - 823
(2017/08/02)
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- Identification of novel decenoic acids in heated butter
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Novel decenoic acids such as (E)-4-decenoic acid and (E)- and (Z)-5-,6-decenoic acid were detected as minor components in heated butter using GC and GC/MS. The formation mechanism of these novel decenoic acids is discussed on the basis of the result of the reaction of δ-decalactone with active clay in a model experiment.
- Ito, Nobuhiko,Wada, Shigeru,Yamanaka, Yousuke,Takagaki, Hitoshi,Nakamura, Hironori
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p. 2416 - 2420
(2008/02/03)
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- Bioisosteric approach to elucidation of binding of the acetate group of a moth sex pheromone component to its receptor
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A number of analogs of (Z)-5-decenyl acetate, a pheromone component of the turnip moth, Agrotis segetum, in which the acetate group has been replaced by functional groups that may function as bioisosters, have been synthesized and tested using single-cell electrophysiology. The activities have been interpreted in terms of the molecular electrostatic potentials of the polar functional group as calculated by ab initio quantum mechanical calculations. It is concluded that both oxygens of the acetate group in (Z)-5-decenyl acetate contribute to the interactions between the pheromone component and its receptor. Furthermore, the results indicate that the crucial interaction between the carbonyl group and the receptor, which is most probably a hydrogen bonding interaction, takes place in a direction pointing away from the hydrocarbon chain of the pheromone component.
- Gustavsson, Anna-Lena,Tuvesson, Malena,Larsson, Mattias C.,Wenqi, Wu,Hansson, Bill S.,Liljefors, Tommy
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p. 2755 - 2776
(2007/10/03)
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