1647-16-1Relevant academic research and scientific papers
Ethenolysis reactions catalyzed by imido alkylidene monoaryloxide monopyrrolide (MAP) complexes of molybdenum
Marinescu, Smaranda C.,Schrock, Richard R.,Mueller, Peter,Hoveyda, Amir H.
, p. 10840 - 10841 (2009)
(Chemical Equation Presented) Monoaryloxide-pyrrolide (MAP) olefin metathesis catalysts of molybdenum that contain a chiral bitetralin-based aryloxide ligand are efficient for ethenolysis of methyl oleate, cyclooctene, and cyclopentene. Ethenolysis of 5000 equiv of methyl oleate produced 1-decene (1D) and methyl-9-decenoate (M9D) with a selectivity of >99%, yields up to 95%, and a TON (turnover number) of 4750 in 15 h. Tungstacyclobutane catalysts gave yields approximately half those of molybdenum catalysts, either at room temperature or at 50 °C, although selectivity was still >99%. Ethenolysis of 30000 equiv of cyclooctene to 1,9-decadiene could be carried out with a TON of 22500 at 20 atm (75% yield), while ethenolysis of 10000 equiv of cyclopentene to 1,6-heptadiene could be carried out with a TON of 5800 at 20 atm (58% yield). There is no reason to propose that the efficiency of ethenolysis has been maximized with the most successful catalyst reported here.
SYNTHESIS OF METHYL KETONES BY RHODIUM AND RUTHENIUM CATALYZED OXIDATION REACTIONS UNDER PHASE TRANSFER CONDITIONS
Januszkiewicz, Krzysztof,Alper, Howard
, p. 5163 - 5164 (1983)
The use of rhodium and ruthenium complexes as catalysts for the phase transfer catalyzed oxidation of olefins is described, and compared with the palladium catalyzed Wacker reaction.
Luminescent tungsten(vi) complexes as photocatalysts for light-driven C-C and C-B bond formation reactions
Chan, Kaai-Tung,Che, Chi-Ming,Du, Lili,Liu, Yungen,Phillips, David Lee,To, Wai-Pong,Tong, Glenna So Ming,Wu, Liang-Liang,Yu, Daohong
, p. 6370 - 6382 (2020/07/15)
The realization of photocatalysis for practical synthetic application hinges on the development of inexpensive photocatalysts which can be prepared on a large scale. Herein an air-stable, visible-light-absorbing photoluminescent tungsten(vi) complex which can be conveniently prepared at the gram-scale is described. This complex could catalyse photochemical organic transformation reactions including borylation of aryl halides, such as aryl chloride, reductive coupling of benzyl bromides for C-C bond formation, reductive coupling of phenacyl bromides, and decarboxylative coupling of redox-active esters of alkyl carboxylic acid with high product yields and broad functional group tolerance.
Unprecedented Selectivity of Ruthenium Iodide Benzylidenes in Olefin Metathesis Reactions
Ivry, Elisa,Lemcoff, N. Gabriel,Nechmad, Noy B.,Phatake, Ravindra,Poater, Albert
, p. 3539 - 3543 (2020/02/04)
The development of selective olefin metathesis catalysts is crucial to achieving new synthetic pathways. Herein, we show that cis-diiodo/sulfur-chelated ruthenium benzylidenes do not react with strained cycloalkenes and internal olefins, but can effectively catalyze metathesis reactions of terminal dienes. Surprisingly, internal olefins may partake in olefin metathesis reactions once the ruthenium methylidene intermediate has been generated. This unexpected behavior allows the facile formation of strained cis-cyclooctene by the RCM reaction of 1,9-undecadiene. Moreover, cis-1,4-polybutadiene may be transformed into small cyclic molecules, including its smallest precursor, 1,5-cyclooctadiene, by the use of this novel sequence. Norbornenes, including the reactive dicyclopentadiene (DCPD), remain unscathed even in the presence of terminal olefin substrates as they are too bulky to approach the diiodo ruthenium methylidene. The experimental results are accompanied by thorough DFT calculations.
Nickel-catalyzed deoxygenation of oxiranes: Conversion of epoxides to alkenes
Mori, Takamichi,Takeuchi, Yoshihito,Hojo, Makoto
supporting information, (2020/01/24)
Deoxygenation of epoxides takes place under the catalysis of nickel in the presence of diethylzinc as a deoxygenation agent to yield alkenes. Epoxides with a wide variety of substitution patterns are deoxygenated in this catalytic system to give terminal, 1,1-disubstituted, 1,2-disubstituted, trisubstituted, and tetrasubstituted alkenes in high yields. Reactions of 1,2-disubstituted epoxides we examined proceeded in an E-stereoselective manner. High compatibility with other functional groups through this transformation was also observed.
Method for synthesizing 1,9-decadiene
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Paragraph 0036; 0038; 0039, (2019/07/01)
The invention discloses a method for synthesizing 1,9-decadiene. The method sequentially comprises the following steps: adding carboxylic acid and 1,10-decadienol into a reaction container, heating the container until the 1,10-decadienol is dissolved, adding a catalyst, carrying out an esterification reaction at 120-200 DEG C, and collecting water evaporated in the esterification reaction; continuously heating the container to 300-350 DEG C after no water is produced in the esterification reaction, carrying out a reaction for 5-8 h, and evaporating and collecting a mixed solution of 1,9-decadiene and carboxylic acid; and respectively post-processing the mixed of 1,9-decadiene and carboxylic acid to obtain carboxylic acid and 1,9-decadiene respectively. The method for preparing 1,9-decadiene is efficient, economical and green, and meets industrial production requirements.
Oxidative Dehydroxymethylation of Alcohols to Produce Olefins
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Paragraph 0057; 0058, (2019/09/06)
Catalyst compositions for the conversion of aldehyde compounds and primary alcohol compounds to olefins are disclosed herein. Reactions include oxidative dehydroxymethylation processes and oxidative dehydroformylation methods, which are beneficially conducted in the presence of a sacrificial acceptor of H2 gas, such as N,N-dimethylacrylamide.
Fluoro-imidazopyridinylidene Ruthenium Catalysts for Cross Metathesis with Ethylene
Byun, Seunghwan,Seo, Huiyeong,Choi, Jun-Ho,Ryu, Ji Yeon,Lee, Junseong,Chung, Won-Jin,Hong, Sukwon
supporting information, p. 4121 - 4132 (2019/10/16)
A series of ruthenium metathesis catalysts bearing fluorinated imidazo[1,5-a]pyridin-3-ylidene carbenes (F-ImPy) were developed for ethenolysis (cross metathesis with ethylene) of methyl oleate. X-ray crystal structure analysis shows Ru-F interaction, and this fluorine substitution appears to be pivotal to have stable ImPy-Ru precatalysts. Ligand structure was varied for high catalyst activity and cross metathesis selectivity in ethenolysis reaction. F-ImPy-Ru catalysts showed high selectivity in ethenolysis of methyl oleate and thermal robustness under an ethylene atmosphere.
Probing the Existence of a Metastable Binding Site at the β2-Adrenergic Receptor with Homobivalent Bitopic Ligands
Gaiser, Birgit I.,Danielsen, Mia,Marcher-R?rsted, Emil,R?pke J?rgensen, Kira,Wróbel, Tomasz M.,Frykman, Mikael,Johansson, Henrik,Br?uner-Osborne, Hans,Gloriam, David E.,Mathiesen, Jesper Mosolff,Sejer Pedersen, Daniel
, p. 7806 - 7839 (2019/09/07)
Herein, we report the development of bitopic ligands aimed at targeting the orthosteric binding site (OBS) and a metastable binding site (MBS) within the same receptor unit. Previous molecular dynamics studies on ligand binding to the β2-adrenergic receptor (β2AR) suggested that ligands pause at transient, less-conserved MBSs. We envisioned that MBSs can be regarded as allosteric binding sites and targeted by homobivalent bitopic ligands linking two identical pharmacophores. Such ligands were designed based on docking of the antagonist (S)-alprenolol into the OBS and an MBS and synthesized. Pharmacological characterization revealed ligands with similar potency and affinity, slightly increased β2/β1AR-selectivity, and/or substantially slower β2AR off-rates compared to (S)-alprenolol. Truncated bitopic ligands suggested the major contribution of the metastable pharmacophore to be a hydrophobic interaction with the β2AR, while the linkers alone decreased the potency of the orthosteric fragment. Altogether, the study underlines the potential of targeting MBSs for improving the pharmacological profiles of ligands.
Tandem Catalysis: Transforming Alcohols to Alkenes by Oxidative Dehydroxymethylation
Wu, Xuesong,Cruz, Faben A.,Lu, Alexander,Dong, Vy M.
supporting information, p. 10126 - 10130 (2018/08/23)
We report a Rh-catalyst for accessing olefins from primary alcohols by a C-C bond cleavage that results in dehomologation. This functional group interconversion proceeds by an oxidation-dehydroformylation enabled by N,N-dimethylacrylamide as a sacrificial acceptor of hydrogen gas. Alcohols with diverse functionality and structure undergo oxidative dehydroxymethylation to access the corresponding olefins. Our catalyst protocol enables a two-step semisynthesis of (+)-yohimbenone and dehomologation of feedstock olefins.
