- Triflimide-Catalysed Rearrangement of N-(1-Trimethylsilyl)allylhydrazones Results in the Formation of Vinylsilanes and Cyclopropanes
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A synthesis of terminal vinylsilanes by triflimide-catalysed rearrangement of N-(1-trimethylsilyl)allylhydrazones is reported. This protocol provides a convenient access to versatile olefinic building blocks through a traceless bond construction. Hydrazones derived from aromatic aldehydes give cis-cyclopropanes in an unexpected side-reaction.
- Dittrich, Sebastian,Bracher, Franz
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- Transition-metal-catalyzed sequential cross-coupling of bis(iodozincio)methane and -ethane with two different organic halides
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Bis(iodozincio)methane, prepared from diiodomethane and zinc, reacts with an organic halide in the presence of a transition-metal catalyst to give an iodozinciomethylenated compound; this then reacts with another organic halide to form a C-C bond. The overall process connects two electrophiles with one carbon atom. Bis(iodozincio)ethane can also undergo this transformation, yielding a new stereogenic center. The asymmetric induction of this stereogenic center was investigated by using a chiral palladium catalyst.
- Yoshino, Hideaki,Toda, Narihiro,Kobata, Masami,Ukai, Katsumi,Oshima, Koichiro,Utimoto, Kiitiro,Matsubara, Seijiro
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- Ni-Catalyzed Carboxylation of Aziridines en Route to β-Amino Acids
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A Ni-catalyzed reductive carboxylation of N-substituted aziridines with CO2 at atmospheric pressure is disclosed. The protocol is characterized by its mild conditions, experimental ease, and exquisite chemo- and regioselectivity pattern, thus unlocking a new catalytic blueprint to access β-amino acids, important building blocks with considerable potential as peptidomimetics.
- Davies, Jacob,Janssen-Müller, Daniel,Zimin, Dmitry P.,Day, Craig S.,Yanagi, Tomoyuki,Elfert, Jonas,Martin, Ruben
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supporting information
p. 4949 - 4954
(2021/04/07)
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- Access to Trisubstituted Fluoroalkenes by Ruthenium-Catalyzed Cross-Metathesis
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Although the olefin metathesis reaction is a well-known and powerful strategy to get alkenes, this reaction remained highly challenging with fluororalkenes, especially the Cross-Metathesis (CM) process. Our thought was to find an easy accessible, convenient, reactive and post-functionalizable source of fluoroalkene, that we found as the methyl 2-fluoroacrylate. We reported herein the efficient ruthenium-catalyzed CM reaction of various terminal and internal alkenes with methyl 2-fluoroacrylate giving access, for the first time, to trisubstituted fluoroalkenes stereoselectively. Unprecedent TON for CM involving fluoroalkene, up to 175, have been obtained and the reaction proved to be tolerant and effective with a large range of olefin partners giving fair to high yields in metathesis products. (Figure presented.).
- Nouaille, Augustin,Pannecoucke, Xavier,Poisson, Thomas,Couve-Bonnaire, Samuel
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supporting information
p. 2140 - 2147
(2021/03/06)
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- Controllable Isomerization of Alkenes by Dual Visible-Light-Cobalt Catalysis
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We report herein that thermodynamic and kinetic isomerization of alkenes can be accomplished by the combination of visible light with Co catalysis. Utilizing Xantphos as the ligand, the most stable isomers are obtained, while isomerizing terminal alkenes over one position can be selectively controlled by using DPEphos as the ligand. The presence of the donor–acceptor dye 4CzIPN accelerates the reaction further. Transformation of exocyclic alkenes into the corresponding endocyclic products could be efficiently realized by using 4CzIPN and Co(acac)2 in the absence of any additional ligands. Spectroscopic and spectroelectrochemical investigations indicate CoI being involved in the generation of a Co hydride, which subsequently adds to alkenes initiating the isomerization.
- Meng, Qing-Yuan,Schirmer, Tobias E.,Katou, Kousuke,K?nig, Burkhard
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supporting information
p. 5723 - 5728
(2019/04/03)
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- In Situ Generated Gold Nanoparticles on Active Carbon as Reusable Highly Efficient Catalysts for a Csp3 ?Csp3 Stille Coupling
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Gold nanoparticle catalysts are important in many industrial production processes. Nevertheless, for traditional Csp2-Csp2 cross-coupling reactions they have been rarely used and Pd catalysts usually give a superior performance. Herein we report that in situ formed gold metal nanoparticles are highly active catalysts for the cross coupling of allylstannanes and activated alkylbromides to form Csp3-Csp3 bonds. Turnover numbers up to 29 000 could be achieved in the presence of active carbon as solid support, which allowed for convenient catalyst recovery and reuse. The present study is a rare case where a gold metal catalyst is superior to Pd catalysts in a cross-coupling reaction of an organic halide and an organometallic reagent.
- Holz, Julia,Pfeffer, Camilla,Zuo, Hualiang,Beierlein, Dennis,Richter, Gunther,Klemm, Elias,Peters, René
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supporting information
p. 10330 - 10334
(2019/06/27)
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- Umpolung of Carbonyl Groups as Alkyl Organometallic Reagent Surrogates for Palladium-Catalyzed Allylic Alkylation
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Palladium-catalyzed allylic alkylation of nonstabilized carbon nucleophiles is difficult and remains a major challenge. Reported here is a highly chemo- and regioselective direct palladium-catalyzed C-allylation of hydrazones, generated from carbonyls, as a source of umpolung unstabilized alkyl carbanions and surrogates of alkyl organometallic reagents. Contrary to classical allylation techniques, this umpolung reaction utilizes hydrazones prepared not only from aryl aldehydes but also from alkyl aldehydes and ketones as renewable feedstocks. This strategy complements the palladium-catalyzed coupling of unstabilized nucleophiles with allylic electrophiles by providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.
- Zhu, Dianhu,Lv, Leiyang,Li, Chen-Chen,Ung, Sosthene,Gao, Jian,Li, Chao-Jun
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supporting information
p. 16520 - 16524
(2018/11/23)
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- Dimethyldioxirane (DMDO) as a valuable oxidant for the synthesis of polyfunctional aromatic imidazolium monomers bearing epoxides
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Conventional organic salts represent a new paradigm in many areas of research. Despite their great potential, an improvement in their physicochemical properties requires the chemical modification of their intrinsic structure. Thus, an efficient pathway was developed for the preparation of polyfunctional imidazolium monomers incorporating aromatic rings and terminal epoxides which presented a real synthetic challenge. In this work, we describe the reactivity of various oxidizing agents to develop a strong, clean and powerful methodology to generate epoxidized salts. Various reaction conditions for the formation of the epoxides were investigated such as the role of the cation and the counterion as well as the influence of an aromatic and/or aliphatic linker chain. Finally, we have evaluated the thermal properties of these new polyfunctional salts by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).
- Chardin,Rouden,Livi,Baudoux
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supporting information
p. 5054 - 5059
(2017/11/09)
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- INFRARED SENSOR, NEAR-INFRARED ABSORBING COMPOSITION, CURED FILM, NEAR-INFRARED ABSORBING FILTER, IMAGE SENSOR, CAMERA MODULE, AND COMPOUND
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Provided are an infrared sensor, a near-infrared absorbing composition, a cured film, a near-infrared absorbing filter, an image sensor, a camera module, and a compound. An infrared sensor 100 which has an infrared transmitting filter 113 and a near-infra
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Paragraph 0420; 0432; 0435
(2017/01/31)
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- CYCLOPROPANECARBOXYLIC ACID GPR120 MODULATORS
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The present invention provides compounds of Formula (I): or a stereoisomer, or a pharmaceutically acceptable salt thereof, wherein all of the variables are as defined herein. These compounds are GPR120 G protein coupled receptor modulators which may be used as medicaments
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Paragraph 0512; 0513
(2017/09/21)
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- Compound, a liquid crystal display element and a liquid crystal composition
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PROBLEM TO BE SOLVED: To provide a compound having a lower viscosity than a conventional linear-cyclic compound and having excellent compatibility with a liquid crystal composition, and to provide a liquid crystal composition and a liquid crystal display
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Paragraph 0080; 0081; 0082
(2017/08/04)
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- BIMESOGENIC COMPOUNDS AND MESOGENIC MEDIA
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The invention relates to bimesogenic compounds of formula I wherein R11, R12, MG11, MG12, X11, X12 and Sp1 have the meaning given in claim 1, to the use of bimesogenic compounds of formula I in liquid crystal media and particular to flexoelectric liquid crystal devices comprising a liquid crystal medium according to the present invention.
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Paragraph 0254-0256
(2017/12/15)
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- Nickel-Catalyzed Cross-Coupling of Redox-Active Esters with Boronic Acids
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A transformation analogous in simplicity and functional group tolerance to the venerable Suzuki cross-coupling between alkyl-carboxylic acids and boronic acids is described. This Ni-catalyzed reaction relies upon the activation of alkyl carboxylic acids as their redox-active ester derivatives, specifically N-hydroxy-tetrachlorophthalimide (TCNHPI), and proceeds in a practical and scalable fashion. The inexpensive nature of the reaction components (NiCl2?6 H2O—$9.5 mol?1, Et3N) coupled to the virtually unlimited commercial catalog of available starting materials bodes well for its rapid adoption.
- Wang, Jie,Qin, Tian,Chen, Tie-Gen,Wimmer, Laurin,Edwards, Jacob T.,Cornella, Josep,Vokits, Benjamin,Shaw, Scott A.,Baran, Phil S.
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supporting information
p. 9676 - 9679
(2016/08/10)
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- Single-Molecule Investigation of Initiation Dynamics of an Organometallic Catalyst
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The action of molecular catalysts comprises multiple microscopic kinetic steps whose nature is of central importance in determining catalyst activity and selectivity. Single-molecule microscopy enables the direct examination of these steps, including eluc
- Ng, James D.,Upadhyay, Sunil P.,Marquard, Angela N.,Lupo, Katherine M.,Hinton, Daniel A.,Padilla, Nicolas A.,Bates, Desiree M.,Goldsmith, Randall H.
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supporting information
p. 3876 - 3883
(2016/04/09)
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- PHENYL-(AZA)CYCLOALKYL CARBOXYLIC ACID GPR120 MODULATORS
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The present invention provides compounds of Formula (I): or a stereoisomer, or a pharmaceutically acceptable salt thereof, wherein all of the variables are as defined herein. These compounds are GPR120 G protein-coupled receptor modulators which may be used as medicaments.
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Paragraph 00193
(2016/04/20)
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- Monocarboxylation and intramolecular coupling of butenylated arenes via palladium-catalyzed C-H activation process
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A novel and practical reaction for the direct intramolecular oxidative coupling of butenylated arenes is reported. With the catalysis of Pd(OAc)2, reactions of various butenylated arenes and carboxylic acids with Selectfluor reagent in CH3CN solution afforded the corresponding monocarboxylation/cyclization products in good yields under mild conditions. This research demonstrated an economic method with the synthesis of 2-tetralyl carboxylic esters, a valuable class of bioactive compounds.
- Liu, Rui,Lu, Ze-Hai,Hu, Xiao-Hui,Li, Jun-Li,Yang, Xian-Jin
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supporting information
p. 1489 - 1492
(2015/03/30)
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- Multifunctional mesoporous silica catalyst
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The present invention provides bifunctional silica mesoporous materials, including mesoporous silica nanoparticles (“MSN”), having pores modified with diarylammonium triflate and perfluoroaryl moieties, that are useful for the acid-catalyzed esterification of organic acids with organic alcohols.
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Page/Page column 8; 9
(2015/04/15)
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- Chemo-, regio-, and stereoselective iron-catalysed hydroboration of alkenes and alkynes
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The highly chemo-, regio-, and stereoselective synthesis of alkyl- and vinyl boronic esters with good functional group tolerance has been developed using in situ activation of a bench-stable iron(ii) pre-catalyst and pinacolborane (16 examples, 45-95% yield, TOF up to 30000 mol h-1). The first iron-catalysed alkene hydrogermylation is also reported.
- Greenhalgh, Mark D.,Thomas, Stephen P.
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supporting information
p. 11230 - 11232
(2013/11/19)
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- Terminal olefins to linear α,β-unsaturated ketones: Pd(II)/hypervalent iodine co-catalyzed wacker oxidation-dehydrogenation
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Development of a mild (35 C, no Bronsted acids) tandem Wacker oxidation-dehydrogenation of terminal olefins was accomplished using palladium(II) and hypervalent iodine co-catalysis. The reaction affords linear aryl and alkyl α,β-unsaturated ketones directly from readily available terminal olefins in good yields (average 75% per step) with excellent functional group tolerance and chemo- and stereoselectivities. The hypervalent iodine co-catalyst was found to be critical for dehydrogenation but was not effective as a stoichiometric oxidant.
- Bigi, Marinus A.,White, M. Christina
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supporting information
p. 7831 - 7834
(2013/07/19)
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- Dual role of allylsamarium bromide as a Grignard reagent and a single electron transfer reagent in the one-pot synthesis of terminal olefins
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The utility of allylsamarium bromide, both as a nucleophilic reagent and a single-electron transfer reagent, in the reaction of carbonyl compounds with allylsamarium bromide in the presence of diethyl phosphate is reported in this communication. From a synthetic point of view, a simple one-pot method for the preparation of terminal olefins is developed.
- Li, Ying,Hu, Yuan-Yuan,Zhang, Song-Lin
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supporting information
p. 10635 - 10637
(2013/11/06)
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- Fullerene-templated synthesis of a cyclic porphyrin trimer using olefin metathesis
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An olefination approach to the construction of covalently linked cyclic metalloporphyrin trimers is presented using fullerenes such as C60 or C70 as a template. Yields of the trimer approach 60%. In the absence of a template, the maj
- Mulholland, Amy R.,Woodward, Clint P.,Langford, Steven J.
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supporting information; experimental part
p. 1494 - 1496
(2011/03/20)
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- Hyperbranched polycarbosilanes of homogeneous architecture: Regioselective hydrosilylation of AB2 monomers and consecutive functionalization
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A novel AB2 monomer, bis(4-(but-3-enyl)phenyl)methylsilane, la, and its analogue AB structure lb were synthesized and polymerized with Karstedt's, Speier's, and a Pt-NHC catalyst to obtain hyperbranched and linear polycarbosilanes. Only the Pt-
- Will, Ulrike,Veljanovski, Draganco,Haerter, Peter,Rieger, Bernhard
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scheme or table
p. 934 - 938
(2011/10/08)
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- Orthogonal reactivity in boryl-substituted organotrifluoroborates
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A method was developed for the hydroboration of alkenyl-containing organotrifluoroborates to generate dibora intermediates. The reactivity differences between organotrifluoroborates and trialkylboranes facilitated the cross-coupling of the borane moiety o
- Molander, Gary A.,Sandrock, Deidre L.
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supporting information; experimental part
p. 15792 - 15793
(2009/05/15)
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- HEME-OXYGENASE INHIBITORS AND USE OF THE SAME IN THE TREATMENT OF CANCER AND DISEASES OF THE CENTRAL NERVOUS SYSTEM
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Disclosed are compounds of the general formula (1): compositions comprising an effective amount of said compounds either alone or in combination with other chemotherapeutic agents, and methods useful for treating or preventing cancer and for inhibiting tumour tissue growth. These compounds attenuate the oxidative damage associated with increased heme-oxygenase activity and can reduce cell proliferation in transformed cells. In addition, the described compounds and compositions are useful as neuroprotectants and for treating or preventing neurodegenerative disorders and other diseases of the central nervous system.
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Page/Page column 72-73
(2009/01/24)
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- 4-Dihydroxyborylphenyl Analogues of 1-Aminocyclobutanecarboxylic Acids: Potential Boron Neutron Capture Therapy Agents
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A series of 4-dihydroxyborylphenyl analogues of an unnatural α-amino acid, 1-aminocyclobutanecarboxylic acid (ACBC), was synthesized. Varying numbers of methylene units were introduced between the 4-boronophenyl and ACBC moieties in order to introduce different degrees of lipophilicity into the molecules. The key step in the syntheses was the preparation of the precursor p-boronophenyl-substituted cyclobutanones which were subsequently converted to the desired amino acids via the Bucherer-Strecker reaction.
- Srivastava, Rajiv R.,Singhaus, Robert R.,Kabalka, George W.
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p. 8495 - 8500
(2007/10/03)
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- Cyclosiloxanes containing mesogenic side groups
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The present invention relates to cyclic siloxanes which have at least one group of formula (1) bonded to a silicon atom in which x is an integer having a value of at least 2, preferably having a value of from 2 to 10, R" is a chemical bond or a divalent r
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- Organosilylalkylaromatic compounds
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The present invention relates to compounds of the formula STR1 in which Y represents an organosilicon radical; R" represents a divalent radical which connects the radical Y to the benzene ring via a chain of at least three atoms; X represents a radical of the formula --COOH, --CN, --CHO, --NH2 or --OH, in which it is possible to block the hydroxyl group with a protecting group; Z represents the same or different substituents in the 2-, 3-, 5- or 6-position to the radical X, preferably hydrogen or halogen atoms; and p represents a value of 0 to 4; and the use of these and related compounds in the preparation of compounds having liquid-crystalline properties.
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