- A convenient method for the synthesis of terminal (E)-1,3-dienes
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Lithiated allylic phosphonates undergo efficient olefination reactions with a variety of aldehydes in the presence of HMPA to give terminal 1,3-dienes with high selectivity for the E-isomer. This method is general and procedurally simple.
- Wang,West
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- Palladium-catalyzed inter- and intramolecular hydroamination of methylenecyclopropanes with amines
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The inter- and intramolecular addition of nitrogen pronucleophiles to methylenecyclopropanes proceeds smoothly in the presence of palladium catalyst, giving the corresponding hydroamination products in good to excellent yields. The reaction proceeds mainl
- Nakamura,Itagaki,Yamamoto
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- Catalyst Controlled Regiodivergent Arylboration of Dienes
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A method for the regiodivergent arylboration of dienes is presented. These reactions allow for the formation of a diverse range of synthetically versatile products from simple precursors. Through mechanistic studies, these reactions likely operate by init
- Sardini, Stephen R.,Brown, M. Kevin
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- Enantioselective Addition of Pyrazoles to Dienes**
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We report the first enantioselective addition of pyrazoles to 1,3-dienes. Secondary and tertiary allylic pyrazoles can be generated with excellent regioselectivity. Mechanistic studies support a pathway distinct from previous hydroaminations: a Pd0-catalyzed ligand-to-ligand hydrogen transfer (LLHT). This hydroamination tolerates a range of functional groups and advances the field of diene hydrofunctionalization.
- Dong, Vy M.,Jiu, Alexander Y.,Slocumb, Hannah S.,Yang, Xiao-Hui,Yeung, Charles S.
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- A STEREO- AND REGIO-SPECIFIC ADDITION OF ν3-TRIMETHYLSILYLALLYLTITANIUM COMPOUND WITH ALDEHYDES. A FACILE AND STEREOCONTROLLED SYNTHESIS OF E- AND Z-TERMINAL DIENES
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ν3-Trimethylsilylallyltitanium compound, (ν5-C5H5)2Ti(ν3-1-trimethylsilylallyl), reacts with aldehydes to give (+/-)-(R,S)-3-trimethylsilyl-4-hydroxy-1-alkenes in excellent yields, which can be deoxysilylated to either E- or Z-1,3-dienes.
- Sato, Fumie,Suzuki, Yoshito,Sato, Masao
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- Tandem Cyclopropanation/Vinylogous Cloke-Wilson Rearrangement for the Synthesis of Heterocyclic Scaffolds
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Cyclopropanation of 1,3-dienes with ethyl 2-formyldiazoacetate under rhodium catalysis results in either a tandem cyclopropanation/Cloke-Wilson rearrangement or a vinylogous variant, depending on the diene used. These adducts may be subjected to an oxygen
- Piotrowski, Mathew L.,Kerr, Michael A.
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- Copolymerization of 1,3-butadiene with phenyl/phenethyl substituted 1,3-butadienes: a direct strategy to access pendant phenyl functionalized polydienes
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Copolymerization of 1,3-butadiene with various types of phenyl substituted 1,3-butadiene derivatives, including (E)-1-phenyl-1,3-butadiene (PBD), 1-phenethyl-1,3-butadiene (PEBD), 1-(4-methoxylphenyl)-1,3-butadiene (p-MEPBD), 1-(2-methoxylphenyl)-1,3-buta
- Li, Dexin,Lin, Juan,Liu, Heng,Wang, Feng,Zhang, Chunyu,Zhang, Xuequan
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- Synthesis and heck reactions of ethenyl- and (Z)-butadien-1-yl nonaflate obtained by the fragmentation of furan derivatives
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The nonaflation of lithium enolates or of silyl enol ethers, formally derived from acetaldehyde or crotonaldehyde, with nonafluorobutanesulfonyl fluoride gave ethenyl nonaflate (1b) and (Z)-buta-1,3-dien-1-yl nonaflate (2) in good yields. The required enolates were obtained by aldehyde-free routes by the lithiation of tetrahydrofuran or 2,5-dihydrofuran followed by the cyclofragmentation of the metallated heterocycles. The application of this approach to the synthesis of allenyl nonaflate 3 failed, presumably due to the intrinsic instability of this allene derivative. The nonaflates 1b and 2 were also prepared by the fluoride-catalysed reaction of the corresponding silyl enol ethers 5 and 7 with nonafluorobutanesulfonyl fluoride; however, the overall yields are slightly lower for these two-step pathways. The cyclofragmentation of lithiated 2,2-dimethyl-4-methylene-[1,3]dioxolane allowed the easy preparation of trimethylsiloxyallene (10) in moderate yield. The nonaflates 1b and 2 reacted smoothly with monosubstituted alkenes in the presence of a catalytic amount of palladium(II) acetate to give the anticipated Heck coupling products in good to moderate yields and with high stereoselectivities.
- Lyapkalo, Ilya M.,Webel, Matthias,Reissig, Hans-Ulrich
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- Stereoselective and Atom-Economic Alkenyl C-H Allylation/Alkenylation in Aqueous Media by Iridium Catalysis
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A practical and atom-economic protocol for the stereoselective preparation of various 1,4-and 1,3-diene skeletons through iridium-catalyzed directed olefinic C-H allylation and alkenylation of NH-Ts acrylamides in water was developed. This reaction tolerated a wide scope of substrates under simple reaction conditions and enabled successful gram-scale preparation. Furthermore, an asymmetric variant of this reaction giving enantioenriched 1,4-dienes was achieved employing a chiral diene-iridium complex as the catalyst.
- Ding, Liyuan,Huang, Yinhua,Lu, Xiunan,Shen, Wenzhou,Xu, Liangyao,Yu, Feifei,Zhang, Jian,Zhong, Guofu,Zhong, Liangjun
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- A Diverted Aerobic Heck Reaction Enables Selective 1,3-Diene and 1,3,5-Triene Synthesis through C-C Bond Scission
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Substituted 1,3-dienes are valuable synthetic intermediates used in myriad catalytic transformations, yet modern catalytic methods for their preparation in a highly modular fashion using simple precursors are relatively few. We report here an aerobic boron Heck reaction with cyclobutene that forms exclusively linear 1-aryl-1,3-dienes using (hetero)arylboronic acids, or 1,3,5-trienes using alkenylboronic acids, rather than typical Heck products (i.e., substituted cyclobutenes). Experimental and computational mechanistic data support a pericyclic mechanism for C-C bond cleavage that enables the cycloalkene to circumvent established limitations associated with diene reagents in Heck-type reactions.
- McAlpine, Neil J.,Wang, Long,Carrow, Brad P.
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- A Practical Synthesis of 1,3-Diene Using Allyltriphenylsilane and Titanium Tetraisopropoxide
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A practical method for the stereoselective preparation of 1,3-dienes by the use of allyltriphenylsilane as a key reagent is described.
- Ikeda, Yoshihiko,Yamamoto, Hisashi
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- Nickel-Catalyzed Enantioselective Hydroboration of Vinylarenes
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The enantioselective hydroboration of vinylarenes catalyzed by a chiral, nonracemic nickel catalyst is presented as a facile method for generating chiral benzylic boronate esters. Various vinylarenes react with bis(pinacolato)diboron (B2pin2) in the presence of MeOH as a hydride source to form chiral boronate esters in up to 92% yield with up to 94% ee. The use of anhydrous Me4NF to activate B2pin2 is crucial for ensuring fast transmetalation to achieve high enantioselectivities.
- Tran, Hai N.,Stanley, Levi M.
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supporting information
p. 395 - 399
(2021/12/27)
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- Selective 1,2-Aminoisothiocyanation of 1,3-Dienes Under Visible-Light Photoredox Catalysis
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Selective three-component 1,2-diamination of 1,3-dienes with concurrent introduction of two orthogonally protected amino groups remains unknown despite its significant synthetic potential. We report herein that reaction of conjugated dienes with N-aminopy
- Guo, Weisi,Wang, Qian,Zhu, Jieping
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supporting information
p. 4085 - 4089
(2020/12/25)
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- Asymmetric Counteranion Directed Catalytic Heck/Tsuji-Trost Annulation of Aryl Iodides and 1,3-Dienes
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A chiral anion-mediated asymmetric Heck/Tsuji-Trost reaction of aryl iodides and 1,3-dienes is presented. Chiral indoline derivatives could be afforded with remarkably higher yields and enantioselectivities than our previous chiral ligand-based method. Silver carbonate is employed as both base and halide scavenger to ensure fast and recyclable exchange of the catalytic amount of chiral anions. Fast salt metathesis, as well as the acceleration effect of the chiral anion, could both benefit the stereocontrol of the reaction.
- Xu, Jia-Cheng,Yin, Yi-Zhuo,Han, Zhi-Yong
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supporting information
p. 3834 - 3838
(2021/05/26)
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- Cobalt-Catalyzed Z to e Geometrical Isomerization of 1,3-Dienes
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An efficient cobalt-catalyzed geometrical isomerization of 1,3-dienes is described. In the combination of a CoCl2 precatalyst with an amido-diphosphine-oxazoline ligand, the geometrical isomerization of E/Z mixtures of 1,3-dienes proceed in a stereoconvergent manner, affording (E) isomers in high stereoselectivity. This facile transformation features a broad substrate scope with good functional group tolerance and could be scaled up to the gram scale smoothly with a catalyst loading of 1 mol %.
- Wang, Wei,He, Shuying,Zhong, Yuqing,Chen, Jianhui,Cai, Cheng,Luo, Yanshu,Xia, Yuanzhi
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- Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis
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The value of catalytic dehydrogenation of aliphatics (CDA) in organic synthesis has remained largely underexplored. Known homogeneous CDA systems often require the use of sacrificial hydrogen acceptors (or oxidants), precious metal catalysts, and harsh reaction conditions, thus limiting most existing methods to dehydrogenation of non- or low-functionalized alkanes. Here we describe a visible-light-driven, dual-catalyst system consisting of inexpensive organophotoredox and base-metal catalysts for room-temperature, acceptorless-CDA (Al-CDA). Initiated by photoexited 2-chloroanthraquinone, the process involves H atom transfer (HAT) of aliphatics to form alkyl radicals, which then react with cobaloxime to produce olefins and H2. This operationally simple method enables direct dehydrogenation of readily available chemical feedstocks to diversely functionalized olefins. For example, we demonstrate, for the first time, the oxidant-free desaturation of thioethers and amides to alkenyl sulfides and enamides, respectively. Moreover, the system's exceptional site selectivity and functional group tolerance are illustrated by late-stage dehydrogenation and synthesis of 14 biologically relevant molecules and pharmaceutical ingredients. Mechanistic studies have revealed a dual HAT process and provided insights into the origin of reactivity and site selectivity.
- Zhou, Min-Jie,Zhang, Lei,Liu, Guixia,Xu, Chen,Huang, Zheng
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supporting information
p. 16470 - 16485
(2021/10/20)
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- Synergistic Pd/Amine-Catalyzed Stereodivergent Hydroalkylation of 1,3-Dienes with Aldehydes: Reaction Development, Mechanism, and Stereochemical Origins
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Metal-hydride-catalyzed hydroalkylation of 1,3-dienes with enolizable carbonyl compounds is an atom- and step-economical method for preparing chiral molecules with allylic stereocenters. Although high diastereo- and enantioselectivities have been achieved
- Wang, Hongfa,Zhang, Qinglong,Zhang, Ruiyuan,Zi, Weiwei
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supporting information
p. 10948 - 10962
(2021/08/03)
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- Nickel-Catalyzed Carboxylation of Conjugated Dienes with Carbon Dioxide and DIBAL-H for the Synthesis of β,γ-Unsaturated Carboxylic Acids
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Conjugated dienes underwent Ni-catalyst-promoted 1,2-hydrocarboxylation in a 1:1 ratio with carbon dioxide under atmospheric pressure in the presence of diisobutylaluminum hydride (DIBAL-H) to give the corresponding β,γ-unsaturated carboxylic acids, without dimerization or oligomerization of the conjugated diene.
- Luo, Ying,Chan, Bun,Fukuda, Tsutomu,Onodera, Gen,Kimura, Masanari
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supporting information
p. 1551 - 1554
(2021/01/21)
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- Manganese-catalysed divergent silylation of alkenes
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Transition-metal-catalysed, redox-neutral dehydrosilylation of alkenes is a long-standing challenge in organic synthesis, with current methods suffering from low selectivity and narrow scope. In this study, we report a general and simple method for the manganese-catalysed dehydrosilylation and hydrosilylation of alkenes, with Mn2(CO)10 as a catalyst precursor, by using a ligand-tuned metalloradical reactivity strategy. This enables versatility and controllable selectivity with a 1:1 ratio of alkenes and silanes, and the synthetic robustness and practicality of this method are demonstrated using complex alkenes and light olefins. The selectivity of the reaction has been studied using density functional theory calculations, showing the use of an iPrPNP ligand to favour dehydrosilylation, while a JackiePhos ligand favours hydrosilylation. The reaction is redox-neutral and atom-economical, exhibits a broad substrate scope and excellent functional group tolerance, and is suitable for various synthetic applications on a gram scale. [Figure not available: see fulltext.].
- Dong, Jie,Yuan, Xiang-Ai,Yan, Zhongfei,Mu, Liying,Ma, Junyang,Zhu, Chengjian,Xie, Jin
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p. 182 - 190
(2020/12/17)
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- Ni-Catalyzed Regioselective Hydroarylation of 1-Aryl-1,3-Butadienes with Aryl Halides
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An efficient nickel-catalyzed regioselective hydroarylation of 1,3-dienes with aryl halides and a silane has been developed, affording a range of allylic arenes in good to excellent yields under mild conditions. This method exhibits broad substrate scope,
- Wang, Chengdong,Guo, Yingjie,Wang, Xiaoming,Wang, Zheng,Ding, Kuiling
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supporting information
p. 15903 - 15907
(2021/10/07)
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- Palladium-Catalyzed Asymmetric Tandem Denitrogenative Heck/Tsuji-Trost of Benzotriazoles with 1,3-Dienes
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The asymmetric denitrogenative cycloaddition has emerged as a powerful tool to build chiral aza-heterocyles. However, only one example of asymmetric denitrogenative cycloaddition of benzotriazole with unsaturated hydrocarbons has been explored so far, bec
- Li, Yin-Lin,Wu, Hai-Hong,Zhang, Junliang,Zhang, Pei-Chao
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supporting information
p. 13010 - 13015
(2021/09/07)
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- Electrochemistry enabled selective vicinal fluorosulfenylation and fluorosulfoxidation of alkenes
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Both sulfur and fluorine play important roles in organic synthesis, the life science, and materials science. The direct incorporation of these elements into organic scaffolds with precise control of the oxidation states of sulfur moieties is of great significance. Herein, we report the highly selective electrochemical vicinal fluorosulfenylation and fluorosulfoxidation reactions of alkenes, which were enabled by the unique ability of electrochemistry to dial in the potentials on demand. Preliminary mechanistic investigations revealed that the fluorosulfenylation reaction proceeded through a radical-polar crossover mechanism involving a key episulfonium ion intermediate. Subsequent electrochemical oxidation of fluorosulfides to fluorosulfoxides were readily achieved under a higher applied potential with the adventitious H2O in the reaction mixture.
- Jiang, Yimin,Shi, Zhaojiang,Wu, Jinnan,Wu, Shaofen,Ye, Keyin,Yu, Yi,Yuan, Yaofeng
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supporting information
(2021/11/17)
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- Enantioselective Synthesis of Functionalized Arenes by Nickel-Catalyzed Site-Selective Hydroarylation of 1,3-Dienes with Aryl Boronates
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A catalytic method for the site-selective and enantioselective synthesis of functionalized arenes by the intermolecular hydroarylation of terminal and internal 1,3-dienes with aryl pinacolato boronates is reported. The reactions are promoted by 5.0 mol %
- Marcum, Justin S.,Meek, Simon J.,Taylor, Tiffany R.
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supporting information
p. 14070 - 14075
(2020/06/10)
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- Photoinduced Palladium-Catalyzed Carbofunctionalization of Conjugated Dienes Proceeding via Radical-Polar Crossover Scenario: 1,2-Aminoalkylation and beyond
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A photoinduced palladium-catalyzed 1,2-carbofunctionalization of conjugated dienes has been developed. This mild modular approach, which does not require employment of exogeneous photosensitizers and external oxidants, allows for efficient and highly regio- and stereoselective synthesis of a broad range of allylic amines from readily available 1,3-dienes, alkyl iodides, and amines. Employment of O- and C-nucleophiles toward oxyalkylation and dialkylation products was also demonstrated. A putative π-allyl palladium radical-polar crossover path is proposed as a key event in this three-component coupling process. The utility of this protocol is highlighted by its application for derivatization of several amine-containing drugs.
- Gevorgyan, Vladimir,Kurandina, Daria,Shing Cheung, Kelvin Pak,Yata, Tetsuji
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supporting information
p. 9932 - 9937
(2020/06/27)
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- Cu-Catalyzed highly regioselective 1,2-hydrocarboxylation of 1,3-dienes with CO2
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A practical copper-catalyzed highly regioselective 1,2-hydrocarboxylation of terminal 1,3-diene with carbon dioxide has been developed. Under mild reaction conditions, this chemistry afforded 2-benzyl-β,γ-unsaturated acid derivatives as products, which are a kind of important unit for bio-active molecules and versatile precursors for organic synthesis, with good functional group tolerance. The key intermediate in this transformation is illustrated by control experiments.
- Zhang, Penglin,Zhou, Zhanglang,Zhang, Rumeng,Zhao, Qian,Zhang, Chun
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supporting information
p. 11469 - 11472
(2020/10/12)
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- Nickel-catalyzed allyl-allyl coupling reactions between 1,3-dienes and allylboronates
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A regiospecific allyl-allyl coupling reaction between 1,3-dienes and allylboronates has been demonstrated under nickel catalysis. Salient features of this method include the earth-abundant metal catalyst, excellent regioselectivity and good functional group tolerance. Notably, even congested allyl substrates can also be applied to this protocol, thus allowing for the rapid preparation of a series of valuable 1,5-dienes. This journal is
- Ji, Ding-Wei,He, Gu-Cheng,Zhang, Wei-Song,Zhao, Chao-Yang,Hu, Yan-Cheng,Chen, Qing-An
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supporting information
p. 7431 - 7434
(2020/07/15)
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- CHIMERIC COMPOUNDS AND METHODS OF MANAGING NEUROLOGICAL DISORDERS OR CONDITIONS
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This disclosure relates to chimeric compounds and methods for managing neurological conditions. In certain embodiments, the compound comprises a chemical structure of a monoamine reuptake inhibitor conjugated to a chemical structure of a histone deacetyla
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Page/Page column 42
(2020/09/12)
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- Stereoselective synthesis of conjugated trienes: Via 1,4-palladium migration/Heck sequence
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Conjugated trienes are ubiquitous structures in natural products and organic functional molecules. An efficient 1,4-palladium migration/Heck sequence was developed for the highly stereoselective synthesis of trisubstituent 1,3,5-trienes, which were found
- Feng, Chen-Guo,He, Zhi-Tao,Li, Meng-Yao,Lin, Guo-Qiang,Xue, Ze-Jian,Zhu, Bin-Bin
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supporting information
p. 14420 - 14422
(2020/12/01)
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- Iron(III)/O2-Mediated Regioselective Oxidative Cleavage of 1-Arylbutadienes to Cinnamaldehydes
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A simple, efficient, and environmentally benevolent regioselective oxidative cleavage of 1-arylbutadienes to cinnamaldehydes mediated by iron(III) sulfate/O2 has been developed. The reaction offered good yields and excellent regioselectivity and showed good functional group tolerance (31 examples). The method is important, as few reports with limited substrate scope are available for such excellent oxidative cleavage of conjugated dienes.
- Bhowmik, Amit,Fernandes, Rodney A.
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p. 9203 - 9207
(2019/11/14)
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- Pd-Catalyzed Synthesis of Vinyl Arenes from Aryl Halides and Acrylic Acid
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Acrylic acid is presented as an inexpensive, non-volatile vinylating agent in a palladium-catalyzed decarboxylative vinylation of aryl halides. The reaction proceeds through a Heck reaction of acrylic acid, immediately followed by protodecarboxylation of the cinnamic acid intermediate. The use of the carboxylate group as a deciduous directing group ensures high selectivity for monoarylated products. The vinylation process is generally applicable to diversely substituted substrates. Its utility is shown by the synthesis of drug-like molecules and the gram-scale preparation of key intermediates in drug synthesis.
- Gao, Yang,Ou, Yang,Goo?en, Lukas J.
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supporting information
p. 8709 - 8712
(2019/06/17)
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- Highly stereoselective and catalytic desulfitative C[sbnd]O and C[sbnd]I dienylation with sulfolenes: The importance of basic additives
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Conjugated dienes and polyenes are central structural motifs of natural products, and key synthetic intermediates in organic synthesis and materials science. We describe herein a palladium-catalyzed dienylation of aryl, heteroaryl, and vinyl triflates, nonaflates and iodides that were previously identified as recalcitrant substrates for the sulfolene-mediated catalytic dienylation. The method has now been successfully expanded to C[sbnd]O and C[sbnd]I dienylation, demonstrating broad scope with respect to sulfonates, iodides and sulfolenes. The reactions proceed with high regio- and stereoselectivity, and efficiency that are strongly influenced by basic additives, whose influence on the reaction performance was systematically studied.
- Dang, Hang T.,Nguyen, Viet D.,Pham, Hoang H.,Arman, Hadi D.,Larionov, Oleg V.
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supporting information
p. 3258 - 3264
(2019/04/14)
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- Iridium-catalyzed alkenyl C-H allylation using conjugated dienes
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An iridium-catalyzed C-H allylation of acrylamides with conjugated dienes was developed, using NH-Ts amide as the directing group. The ligand- and additive-free protocol provided a convenient and atom economic synthesis of branched 1,4-diene skeletons, enabling the tolerance of a wide scope of functionalities such as OMe, F, Cl, Br and CF3. The utility of this protocol is also demonstrated by a preparative scale, as well as C-H functionalization of artemisic amide. Furthermore, NH-Ts amide was efficiently removed by methylation and hydrolysis procedures to provide 1,4-dienoic acid.
- Xu, Liangyao,Meng, Keke,Zhang, Jian,Sun, Yaling,Lu, Xiunan,Li, Tingyan,Jiang, Yan,Zhong, Guofu
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supporting information
p. 9757 - 9760
(2019/08/20)
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- Palladium-Catalyzed Cascade Double C—N Bond Activation: A New Strategy for Aminomethylation of 1,3-Dienes with Aminals
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A new palladium-catalyzed selective aminomethylation of conjugated 1,3-dienes with aminals via double C—N bond activation is described. This simple method provides an effective and rapid approach for the synthesis of linear α,β-unsaturated allylic amines with perfect regioselectivity. Mechanistic studies disclosed that one palladium catalyst cleaved two distinct C—N bond to furnish a cascade double C—N bond activation, in which an allylic 1,3-diamine and allylic 1,2-diamine were initially formed as key intermediates through the palladium-catalyzed C—N bond activation of aminal and the α,β-unsaturated allylic amine was subsequently produced via palladium-catalyzed C—N bond activation of the allylic diamines.
- Qiao, Cuifang,Chen, Anrong,Gao, Bingjian,Liu, Yang,Huang, Hanmin
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supporting information
p. 929 - 933
(2018/09/22)
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- Palladium-Catalyzed Formal [4+2] Cycloaddition of Benzoic and Acrylic Acids with 1,3-Dienes via C—H Bond Activation: Efficient Access to 3,4-Dihydroisocoumarin and 5,6-Dihydrocoumalins
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We report a palladium-catalyzed formal intermolecular [4+2] cycloaddition of benzoic and acrylic acids with 1,3-dienes including the stock chemicals 1,3-butadiene and isoprene leading to synthetically useful 3,4-dihydroisocoumarins and 5,6-dihydrocoumalins. Stepwise C—H bond cleavage and annulation are likely involved in the reaction pathway. The synthetic potential of the methodology was demonstrated by two short derivatizations and total synthesis of natural product Clausamine B.
- Sun, Youwen,Zhang, Guozhu
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supporting information
p. 708 - 711
(2018/06/06)
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- Rhodium-Catalyzed Annulations of 1,3-Dienes and Salicylaldehydes/2-Hydroxybenzyl Alcohols Promoted by 2-Ethylacrolein
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A rhodium-catalyzed 2-ethylacrolein-promoted protocol enables the annulation reactions of 1,3-dienes with either salicylaldehydes or 2-hydroxybenzyl alcohols leading to 2-alkylchroman-4-ones with high regioselectivity. This research highlights the use of 2-ethylacrolein which probably serves as a tool of bidentate coordination to rhodium intermediates. Mechanistic studies reveal that the transformation proceeds through the 1,4-hydroacylation pathway to access unsaturated linear ketones with subsequent oxo-Michael addition. (Figure presented.).
- Li, Hong-Shuang,Xiong, Yang,Zhang, Guozhu
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supporting information
p. 4246 - 4251
(2018/10/02)
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- Palladium-Catalyzed Chemoselective Protodecarboxylation of Polyenoic Acids
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Conditions for the first palladium-catalyzed chemoselective protodecarboxylation of polyenoic acids to give the desired polyenes in good yields are presented. The reactions proceed under mild conditions using either a Pd(0) or Pd(II) catalyst and tolerate a variety of aryl and aliphatic substitutions. Unique aspects of the reaction include the requirement of phosphines, water, and a polyene adjacent to the carboxylic acid.
- Al-Huniti, Mohammed H.,Perez, Mark A.,Garr, Matthew K.,Croatt, Mitchell P.
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supporting information
p. 7375 - 7379
(2019/01/03)
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- Electronically Mismatched Cycloaddition Reactions via First-Row Transition Metal, Iron(III)-Polypyridyl Complex
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The iron(III)-polypyridyl complex and its derivatives showed sufficient oxidizing potential to act as a one-electron oxidant, producing radical cations from olefins and promoting the efficient radical cation [2 + 2] and [2 + 4] cycloaddition reactions. Subsequent chain propagation afforded trisubstituted cyclobutane or cyclohexene derivatives, and this facile route enables the replacement of rare metals with sustainable, green, and inexpensive iron in radical cation cycloadditions.
- Shin, Jung Ha,Seong, Eun Young,Mun, Hyeon Jin,Jang, Yu Jeong,Kang, Eun Joo
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supporting information
p. 5872 - 5876
(2018/09/25)
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- Highly Regio- and Stereoselective Catalytic Synthesis of Conjugated Dienes and Polyenes
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Conjugated dienes and polyenes are typically synthesized by sequential introduction of C=C bonds. Here, we report a practical and scalable, catalytic dienylation that is highly regio- and stereoselective for both C=C bonds. The reaction is enabled by a stereoselective palladium-catalyzed cross-coupling that is preceded by a regioselective base-induced ring opening of readily available sulfolenes. The dienylation reaction is particularly useful for the synthesis of synthetically challenging dienes containing cis double bonds. We also show that the reaction can serve as a synthetic platform for the construction of conjugated polyenes.
- Nguyen, Vu T.,Dang, Hang T.,Pham, Hoang H.,Nguyen, Viet D.,Flores-Hansen, Carsten,Arman, Hadi D.,Larionov, Oleg V.
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supporting information
p. 8434 - 8438
(2018/07/05)
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- Ni-Catalyzed Site-Selective Dicarboxylation of 1,3-Dienes with CO2
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A site-selective catalytic incorporation of multiple CO2 molecules into 1,3-dienes en route to adipic acids is described. This protocol is characterized by its mild conditions, excellent chemo- and regioselectivity and ease of execution under CO2 (1 atm), including the use of bulk butadiene and/or isoprene feedstocks.
- Tortajada, Andreu,Ninokata, Ryo,Martin, Ruben
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supporting information
p. 2050 - 2053
(2018/02/19)
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- Photo-induced Decarboxylative Heck-Type Coupling of Unactivated Aliphatic Acids and Terminal Alkenes in the Absence of Sacrificial Hydrogen Acceptors
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1,2-Disubstituted alkenes such as vinyl arenes, vinyl silanes, and vinyl boronates are among the most versatile building blocks that can be found in every sector of chemical science. We herein report a noble-metal-free method of accessing such olefins through a photo-induced decarboxylative Heck-type coupling using alkyl carboxylic acids, one of the most ubiquitous building blocks, as the feedstocks. This transformation was achieved in the absence of external oxidants through the synergistic combination of an organo photo-redox catalyst and a cobaloxime catalyst, with H2 and CO2 as the only byproducts. Both control experiments and DFT calculations supported a radical-based mechanism, which eventually led to the development of a selective three-component coupling of aliphatic carboxylic acids, acrylates, and vinyl arenes. More than 90 olefins across a wide range of functionalities were effectively synthesized with this simple protocol.
- Cao, Hui,Jiang, Heming,Feng, Hongyu,Kwan, Jeric Mun Chung,Liu, Xiaogang,Wu, Jie
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supporting information
p. 16360 - 16367
(2018/11/27)
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- Highly-functionalized arene synthesis based on palladium on carbon-catalyzed aqueous dehydrogenation of cyclohexadienes and cyclohexenes
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Transition metal-catalyzed dehydrogenation is a clean oxidation method requiring no additional oxidants. We have accomplished a heterogeneous Pd/C-catalyzed aqueous dehydrogenation of 1,4-cyclohexadienes and cyclohexenes to give the corresponding highly-functionalized arenes. Furthermore, various arenes could be efficiently constructed in a one-pot manner via a Diels-Alder reaction and the following dehydrogenation.
- Yasukawa, Naoki,Yokoyama, Hiroki,Masuda, Masahiro,Monguchi, Yasunari,Sajiki, Hironao,Sawama, Yoshinari
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supporting information
p. 1213 - 1217
(2018/03/28)
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- Zinc(II)-Catalyzed Asymmetric Diels-Alder Reaction of (E)-1-Phenyl Dienes with β,γ-Unsaturated α-Ketoesters
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A highly regio-, diastereo-, and enantioselective Diels-Alder reaction of β,γ-unsaturated α-ketoesters with (E)-1-phenyl dienes has been accomplished by using a stable and easily available chiral N,N′-dioxide/zinc(II) complex as catalyst. Only one isomer of the corresponding cyclohexenes with three chiral centers was obtained in good to excellent yields with excellent ee values under mild reaction conditions. The configurations of the product and chiral N,N′-dioxide/zinc(II) catalyst were identified by X-ray diffraction analysis. In addition, a possible catalytic model was proposed to explain the origin of the asymmetric induction.
- Xiong, Qian,Lin, Lili,Zhao, Xiaohu,Lang, Jiawen,Liu, Xiaohua,Feng, Xiaoming
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p. 12527 - 12534
(2018/10/20)
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- Flow Dehydration and Hydrogenation of Allylic Alcohols: Application to the Waste-Free Synthesis of Pristane
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Hydroxy-substituted sulfonic acid functionalized silica (HO-SAS) in combination with THF containing a small amount of water as a solvent proved to be a reliable system for the dehydration of allylic alcohols. This process generally caused dehydration within 1 min through a column reactor charged with HO-SAS. The flow dehydration was sequenced by flow hydrogenation, which resulted in the synthesis of pristane. A scalable flow synthesis of pristane was successfully performed and afforded 10 g of pristane after an operation of 2 h. We also performed dehydration and hydrogenation by using a mixed column of HO-SAS and 10 % Pd/C.
- Furuta, Akihiro,Hirobe, Yuki,Fukuyama, Takahide,Ryu, Ilhyong,Manabe, Yoshiyuki,Fukase, Koichi
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supporting information
p. 1365 - 1368
(2017/03/23)
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- Nickel-Catalyzed Direct Synthesis of Aryl Olefins from Ketones and Organoboron Reagents under Neutral Conditions
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Nickel-catalyzed addition of arylboron reagents to ketones results in aryl olefins directly. The neutral condition allows acidic protons of alcohols, phenols, and malonates to be present, and fragile structures are also tolerated.
- Lei, Chuanhu,Yip, Yong Jie,Zhou, Jianrong Steve
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supporting information
p. 6086 - 6089
(2017/05/08)
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- Batch and Continuous-Flow One-Pot Processes using Amine Diazotization to Produce Silylated Diazo Reagents
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A novel synthesis of trimethylsilyldiazomethane (TMSCHN2) by diazotization of trimethylsilylmethylamine (TMSCH2NH2) is reported using batch and continuous flow synthesis. The latter affords a daily production of 275 g (2.4 mol) of TMSCHN2. Other silylated methylamines were also successfully reacted under the developed reaction conditions to furnish various silicon-bearing diazomethane reagents. The applicability of the process is highlighted by disclosure of batch and continuous flow one-pot esterification and 1,3-dipolar cycloaddition processes. Furthermore, the high-yielding esterification of carboxylic acids with silylated and substituted methylamines in continuous flow is disclosed. Finally, work-up and purification procedures are reported for the preparation of a 2-MeTHF solution of TMSCHN2, which can be used in rhodium-catalyzed methylenation and homologation reactions.
- Audubert, Clément,Gamboa Marin, Oscar Javier,Lebel, Hélène
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supporting information
p. 6294 - 6297
(2017/05/19)
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- A biosynthetically inspired route to substituted furans using the Appel reaction: Total synthesis of the furan fatty acid F5
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Appel reaction conditions have been harnessed to affect a mild biosynthetically inspired dehydration of endoperoxides to deliver multi-substituted electron rich furans. Unlike traditional dehydrative procedures, this method is metal and acid free, and can be achieved under redox neutral conditions. It is general for a range of aryl and alkyl substituted endoperoxides, and is functional group tolerant. Furthermore, this procedure has been used to deliver an effective total synthesis of the furan fatty acid (FFA) F5.
- Lee, Robert J.,Lindley, Martin R.,Pritchard, Gareth J.,Kimber, Marc C.
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supporting information
p. 6327 - 6330
(2017/07/11)
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- Cobalt-Catalyzed Carbonylative Cross-Coupling of Alkyl Tosylates and Dienes: Stereospecific Synthesis of Dienones at Low Pressure
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Despite advances in organometallic cross-coupling of alkyl electrophiles, there are few stereoselective reactions of chiral, nonracemic substrates. Herein we report a stereospecific carbonylative coupling of alkyl tosylates and dienes producing enantioenriched dienones. This catalytic process proceeds under low pressure and mild conditions using a simple cobalt catalyst and extends to diverse tosylate and diene coupling partners. The transformation constitutes a unique, convergent approach to the asymmetric synthesis of valuable carbonyl compounds from easily accessed starting materials.
- Sargent, Brendon T.,Alexanian, Erik J.
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supporting information
p. 12438 - 12440
(2017/09/25)
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- Organoselenium-Catalyzed Regioselective C?H Pyridination of 1,3-Dienes and Alkenes
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An efficient approach for organoselenium-catalyzed regioselective C?H pyridination of 1,3-dienes to form pyridinium salts has been developed. This method was also successfully applied to direct C?H pyridination of alkenes. Fluoropyridinium reagents, or initially loaded pyridine derivatives, acted as pyridine sources in the pyridination reactions. The obtained pyridinium salts could be further converted under different conditions. This work is the first example of catalytic C-2 direct C?H functionalization of 1,3-dienes and the first case of organoselenium-catalyzed C?H pyridination.
- Liao, Lihao,Guo, Ruizhi,Zhao, Xiaodan
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supporting information
p. 3201 - 3205
(2017/03/17)
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- Chiral Pincer Carbodicarbene Ligands for Enantioselective Rhodium-Catalyzed Hydroarylation of Terminal and Internal 1,3-Dienes with Indoles
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Catalytic enantioselective addition of N-heteroarenes to terminal and internal 1,3-dienes is reported. Reactions are promoted by 5 mol % of Rh catalyst supported by a new chiral pincer carbodicarbene ligand that delivers allylic substituted arenes in up to 95% yield and up to 98:2 er. Mechanistic and X-ray evidence is presented that supports that the reaction proceeds via a Rh(III)-η3-allyl.
- Marcum, Justin S.,Roberts, Courtney C.,Manan, Rajith S.,Cervarich, Tia N.,Meek, Simon J.
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supporting information
p. 15580 - 15583
(2017/11/14)
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- Enantioselective Intermolecular Addition of Aliphatic Amines to Acyclic Dienes with a Pd-PHOX Catalyst
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We report a method for the catalytic, enantioselective intermolecular addition of aliphatic amines to acyclic 1,3-dienes. In most cases, reactions proceed efficiently at or below room temperature in the presence of 5 mol % of a Pd catalyst bearing a PHOX ligand, generating allylic amines in up to 97:3 er. The presence of an electron-deficient phosphine within the ligand not only leads to a more active catalyst but also is critical for achieving high site selectivity in the transformation.
- Adamson, Nathan J.,Hull, Ethan,Malcolmson, Steven J.
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supporting information
p. 7180 - 7183
(2017/06/05)
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- Ligand and base additive effects on the reversibility of nucleophilic addition in palladium-catalyzed allylic aminations monitored by nucleophile crossover
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A nucleophile crossover experiment was used to monitor the reversibility of nucleophilic addition of benzylamine to π-allylpalladium complexes. Dppe, dppp, dppb, and PHOX showed more crossover than PPh3and dppm in both DMF and dichloromethane. Crossover was inhibited by the addition of DBU or Cs2CO3, but much less elimination to diene side products was observed with Cs2CO3. Analysis of percent crossover vs. percent reaction completion using the PHOX ligand revealed that with added DBU or Cs2CO3crossover only began occurring after 100% completion had been reached.
- Holtzman, Bryan S.,Roberts, Eric T.,Caminiti, Nicholas S.,Fox, Jacob A.,Goodstein, Madison B.,Hill, Staci A.,Jia, Zitong B.,Leibler, Isabelle N.-M.,Martini, Michael L.,Mendolia, Gina M.,Nodder, Sarah B.,Costanza-Robinson, Molly S.,Bunt, Richard C.
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supporting information
p. 432 - 436
(2017/01/12)
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- Iridium-catalysed desilylative acylation of 1-alkenylsilanes
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We report the iridium-catalysed desilylative acylation of styryl and dienyl silanes by acid anhydrides to afford (E)-α,β-unsaturated ketones. The [{Ir(μ-Cl)(cod)}2] catalyst is the first non-rhodium complex successfully applied for this type of
- Zaranek, Maciej,Skrodzki, Maciej,Szudkowska-Fr?tczak, Justyna,Dodot, Maciej,Kownacki, Ireneusz,Orwat, Bartosz,Pawlu?, Piotr
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- Selective Synthesis of Silacycles by Borane-Catalyzed Domino Hydrosilylation of Proximal Unsaturated Bonds: Tunable Approach to 1,n-Diols
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The tris(pentafluorophenyl)boron-catalyzed domino hydrosilylation of substrates carrying unsaturated functionalities in a proximal arrangement is presented to produce silacycles. Excellent levels of efficiency and selectivity were achieved in the cyclization by the deliberate choice of the hydrosilane reagents. The key to successful cyclic hydrosilylation is the reactivity enhancement of the second intramolecular hydrosilylation by a proximity effect. Not only dienes but also enones, enynes, ynones and enimines readily afford medium-sized silacycles under convenient and mild conditions. The cyclization proceeds with acceptable diastereoselectivity mainly controlled by the conformational bias towards inducing additional stereogenic centers. The silacycles obtained from this reaction were converted to 1,n-diols or 1,n-amino alcohols upon oxidation, thus rendering the present cyclization a powerful tool for accessing synthetically valuable building blocks. (Figure presented.).
- Shin, Kwangmin,Joung, Seewon,Kim, Youyoung,Chang, Sukbok
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supporting information
p. 3428 - 3436
(2017/09/25)
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- Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts
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Carbon-supported Pt nanoparticles (Pt/C) were found to be effective heterogeneous catalysts for the direct Julia olefination of alcohols in the presence of sulfones and KOtBu under oxidant-free conditions. Primary alcohols, including aryl, aliphatic, allyl, and heterocyclic alcohols, underwent olefination with dimethyl sulfone and aryl alkyl sulfones to give terminal and internal olefins, respectively. Secondary alcohols underwent methylenation with dimethyl sulfone. Under 2.5 bar H2, the same reaction system was effective for the transformation of alcohol OH groups to alkyl groups. Structural and mechanistic studies of the terminal olefination system suggested that Pt0 sites on the Pt metal particles are responsible for the rate-limiting dehydrogenation of alcohols and that KOtBu may deprotonate the sulfone reagent. The Pt/C catalyst was reusable after the olefination, and this method showed a higher turnover number (TON) and a wider substrate scope than previously reported methods, which demonstrates the high catalytic efficiency of the present method. Olefination of alcohols: The first heterogeneous catalytic terminal and internal olefination of primary alcohols and methylenation of secondary alcohols with sulfones, a reusable carbon-supported Pt catalyst, and KOtBu is reported (see scheme).
- Hakim Siddiki,Touchy, Abeda Sultana,Kon, Kenichi,Shimizu, Ken-Ichi
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p. 6111 - 6119
(2016/04/26)
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- LSD1 INHIBITORS AND USES THEREOF
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Provided are novel compounds of Formula (I) and pharmaceutically acceptable salts thereof, which are useful for treating a variety of diseases, disorders or conditions, associated with LSDl. Also provided are pharmaceutical compositions comprising the novel compounds of Formula (I), pharmaceutically acceptable salts thereof, and methods for their use in treating one or more diseases, disorders or conditions, associated with LSDl.
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Paragraph 00334-00335
(2016/11/17)
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