- Application of a Ferrocene-Based Palladacycle Precatalyst to Enantioselective Aryl-Aryl Kumada Coupling
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The palladium catalysed reaction of 1-iodo-2-methylnaphthalene and 2-methyl-1-naphthylmagnesium bromide gave quantitatively an (Sa)-configured cross-coupled product in 80 % e.e. using (R,Sp)-PPFA as a ligand. N,N-Dimethylaminomethylferrocene was cyclopalladated (Na2PdCl4, (S)?Ac?Phe?OH, 93 % e.e., as determined by 1H NMR as a result of self-induced non-equivalence), and the resulting (Sp)-configured dimeric palladacycle was employed as a precatalyst for this cross-coupling reaction (5 mol%). Addition to the palladacycle of diphenylphosphine and subsequent base-promoted bidentate ligand synthesis and palladium capture gave an in situ generated catalyst resulting in an (Sp)-configured product in up to 71 % e.e.
- Arthurs, Ross A.,Hughes, David L.,Richards, Christopher J.
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supporting information
(2022/02/21)
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- New bifunctional bis(Azairidacycle) with axial chirality via double cyclometalation of 2,2′-bis(aminomethyl)-1,1’-binaphthyl
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As a candidate for bifunctional asymmetric catalysts containing a half-sandwich C-N chelating Ir(III) framework (azairidacycle), a dinuclear Ir complex with an axially chiral linkage is newly designed. An expedient synthesis of chiral 2,2′-bis(aminomethyl)-1,1′-binaphthyl (1) from 1,1-bi-2-naphthol (BINOL) was accomplished by a three-step process involving nickel-catalyzed cyanation and subsequent reduction with Raney-Ni and KBH4. The reaction of (S)-1 with an equimolar amount of [IrCl2Cp*]2 (Cp* = η5-C5(CH3)5) in the presence of sodium acetate in acetonitrile at 80 ?C gave a diastereomeric mixture of new dinuclear dichloridodiiridium complexes (5) through the double C-H bond cleavage, as confirmed by 1H NMR spectroscopy. A loss of the central chirality on the Ir centers of 5 was demonstrated by treatment with KOC(CH3)3 to generate the corresponding 16e amidoiridium complex 6. The following hydrogen transfer from 2-propanol to 6 provided diastereomers of hydrido(amine)iridium retaining the bis(azairidacycle) architecture. The dinuclear chlorido(amine)iridium 5 can serve as a catalyst precursor for the asymmetric transfer hydrogenation of acetophenone with a substrate to a catalyst ratio of 200 in the presence of KOC(CH3)3 in 2-propanol, leading to (S)-1-phenylethanol with up to an enantiomeric excess (ee) of 67%.
- Ikariya, Takao,Kawata, Yuichi,Kayaki, Yoshihito,Sato, Yasuhiro,Yasui, Shungo
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- The Trityl Cation Embedded into a [7]Helicene-Like Backbone: Preparation and Application as a Lewis Acid Catalyst
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The synthesis of a helically chiral carbenium ion is reported. The new motif is essentially a trityl cation embedded into a [7]helicene-like framework. The key step in its preparation establishes the π-extended fluorenone system in one step by an unprecedented palladium-catalyzed carbonylative annulation of a 4,4′-biphenanthryl-3,3′-diyl precursor. The racemic form of the new carbon Lewis acid was found to catalyze a representative set of reactions typically promoted by the trityl cation.
- Gross, Benjamin M.,Oestreich, Martin
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supporting information
p. 2512 - 2516
(2021/03/22)
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- Trost ligand with axial chiral binaphthyl skeleton and preparation method thereof
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The invention discloses a novel optically pure binaphthyl Trost ligand and a preparation method thereof. (S)-2'-(diarylphosphine)-[1, 1'-binaphthyl]-2-carboxylic acid and chiral diamine are subjectedto condensation reaction to obtain the Trost ligand with
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-
Paragraph 0043; 0048
(2020/09/16)
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- In Situ Generation of Ruthenium Carbonyl Phosphine Complexes as a Versatile Method for the Development of Enantioselective C?O Bond Arylation
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We report here a method for in situ generation of various ruthenium carbonyl phosphine catalysts for arylation via cleavage of inert aromatic carbon–oxygen bonds. The use of catalyst systems consisting of [RuCl2(CO)(p-cymene)], CsF, styrene, an
- Kondo, Hikaru,Kochi, Takuya,Kakiuchi, Fumitoshi
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supporting information
p. 1737 - 1741
(2020/02/05)
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- Asymmetric ketone hydroboration catalyzed by alkali metal complexes derived from BINOL ligands
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The ability of alkali metal complexes featuring functionalized BINOL-derived ligands to catalyze ketone hydroboration reactions was explored. The reduced products were formed in excellent yields and with variable enantioselectivities dependent upon the nature of the ligand and the alkali metal cation.
- Carden, Jamie L.,Melen, Rebecca L.,Newman, Paul D.,Ruddy, Adam J.,Willcox, Darren
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supporting information
p. 2417 - 2420
(2020/03/05)
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- Josiphos-Type Binaphane Ligands for Iridium-Catalyzed Enantioselective Hydrogenation of 1-Aryl-Substituted Dihydroisoquinolines
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Convenient synthesis and useful application of a series of Josiphos-type binaphane ligands were described. The iridium complexes of these chiral diphosphines displayed excellent enantioselectivity and good reactivity in the asymmetric hydrogenation of challenging 1-aryl-substituted dihydroisoquinoline substrates (full conversions, up to >99% ee, 4000 TON). The use of 40% HBr (aqueous solution) as an additive dramatically improved the asymmetric induction of these catalysts. This transformation provided a highly efficient and enantioselective access to chiral 1-aryl-substituted tetrahydroisoquinolines, which were of great importance and common in natural products and biologically active molecules.
- Nie, Huifang,Zhu, Yupu,Hu, Xiaomu,Wei, Zhao,Yao, Lin,Zhou, Gang,Wang, Pingan,Jiang, Ru,Zhang, Shengyong
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supporting information
p. 8641 - 8645
(2019/10/17)
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- Axially Chiral, Electrophilic Fluorophosphonium Cations: Synthesis, Lewis Acidity, and Reactivity in the Hydrosilylation of Ketones
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Axially chiral [(C6F5)3PF][B(C6F5)4] analogues based on dihydrophosphepines with a binaphthyl backbone were prepared and structurally characterized by X-ray diffraction analysis. Computational calculations of FIA and GEI values attest that these new fluorophosphonium cations have a higher Lewis acidity compared to the ubiquitous B(C6F5)3. Furthermore, application of these highly electrophilic compounds in the catalytic hydrosilylation of ketones and an investigation of the mechanism lead to a refined picture of the role of highly electrophilic fluorophosphonium cations.
- Süsse, Lars,Lafortune, James H. W.,Stephan, Douglas W.,Oestreich, Martin
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supporting information
p. 712 - 721
(2019/02/17)
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- Large Scale Synthesis of Chiral (3 Z,5 Z)-2,7-Dihydro-1H-azepine-Derived Hamari Ligand for General Asymmetric Synthesis of Tailor-Made Amino Acids
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An advanced process for large scale (500 g) preparation of a (3Z,5Z)-2,7-dihydro-1H-azepine-derived chiral tridentate ligand (Hamari ligand), widely used for asymmetric synthesis of tailor-made α-amino acids via the corresponding glycine Schiff base Ni(II
- Takahashi, Motohiro,Moriwaki, Hiroki,Miwa, Toshio,Hoang, Brittanie,Wang, Peng,Soloshonok, Vadim A.
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p. 619 - 628
(2019/04/30)
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- Single-component, low molecular weight organic supergelators based on chiral barbiturate scaffolds
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We report here the first chiral barbiturate to act as a single-component LMOG capable of gelating a variety of chlorinated and aromatic solvents. Solution-based DOSY NMR experiments, solid-state VP-SEM, and X-ray crystallography techniques were used to ch
- Seidenkranz, Daniel T.,Langworthy, Kurt A.,Zakharov, Lev N.,Pluth, Michael D.
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p. 499 - 507
(2019/06/27)
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- Design of Phosphinic Acid Catalysts with the Closest Stereogenicity at the α-Position: Synthesis and Application of α-Stereogenic Perfluoroalkyl Phosphinic Acid Catalysts
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Chiral C2-symmetric phosphinic acids were designed based on sterically demanding and helical chiral perfluoroalkyl groups at the closest α-position advancing asymmetric reaction environment and catalytic activity. The perfluoroalkyl catalysts,
- Fujii, Kohei,Todani, Haruki,Ito, Shigekazu,Mikami, Koichi
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supporting information
(2019/05/08)
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- Evaluation of bifunctional chiral phosphine oxide catalysts for the asymmetric hydrosilylation of ketimines
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A series of bifunctional phosphine oxides have been prepared and evaluated as catalysts for the trichlorosilane mediated asymmetric hydrosilylation of ketimines. bis-Phosphine oxides, hydroxy-phosphine oxides, and biaryl phosphine oxides all demonstrated good catalytic activity, but poor to moderate enantioselectivity. A bis-P-chiral phosphine oxide displayed the highest enantioselectivity of 60%.
- Warner, Christopher J.A.,Berry, Sian S.,Jones, Simon
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- Binaphthyl derivative, and material and organic electroluminescent device which contain binaphthyl derivative
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The invention discloses a binaphthyl derivative, and a material and an organic electroluminescent device which contain the binaphthyl derivative. The structure of the binaphthyl derivative is represented by formula I. The binaphthyl derivative represented by formula I possesses deep blue fluorescence performance, is capable of avoiding aggregation-caused quenching effect of fluorescent materials,and is relatively high in vitrification point, heat stability, and excellent in luminescent performance. The synthesis process is simple; a purification method is simple and is suitable for large-scale production; the luminescent performance and heat stability of products can be adjusted through connection with different groups; and the binaphthyl derivative is an ideal selection for organic luminescent layers of organic electroluminescent devices. The OLED devices prepared from the fluorescence material are high in fluorescent layer fluorescence efficiency, and stability, so that device fluorescence efficiency and service life are capable of satisfying practical requirements.
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Paragraph 0090-0094
(2018/11/03)
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- Supramolecular Polymerization of [5]Helicenes. Consequences of Self-Assembly on Configurational Stability
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The supramolecular polymerization of [5]helicenes 1 and 2 is investigated. The self-assembly of these helicenes proceeds by the operation of H-bonding interactions with a negligible participation of π-stacking. The enantiopurity of the sample has a dramatic effect on the supramolecular polymerization mechanism since it reverts the isodesmic mechanism for the racemic mixture to a cooperative one for the enantioenriched sample. Noticeably, the formation of supramolecular polymers efficiently increases the configurational stability of 1,14-unsubstituted [5]helicenes.
- Valera, Jorge S.,Gómez, Rafael,Sánchez, Luis
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supporting information
p. 2020 - 2023
(2018/04/16)
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- Novel binaphthyl and biphenyl α- and β-amino acids and esters: organocatalysis of asymmetric Diels-Alder reactions. A combined synthetic and computational study
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Asymmetric catalysis of the Diels-Alder reaction between cyclopentadiene and cinnamaldehydes has been studied using as catalysts a range of novel α- and β-aminoacids and aminoesters with binaphthyl and biphenyl backbones, providing enantioselectivities of
- Bulman Page, Philip C.,Kinsey, Francesca S.,Chan, Yohan,Strutt, Ian R.,Slawin, Alexandra M. Z.,Jones, Garth A.
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supporting information
p. 7400 - 7416
(2018/10/24)
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- Chiral Bifunctional Phosphine-Carboxylate Ligands for Palladium(0)-Catalyzed Enantioselective C?H Arylation
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Previous enantioselective Pd0-catalyzed C?H activation reactions proceeding via the concerted metalation-deprotonation mechanism employed either a chiral ancillary ligand, a chiral base, or a bimolecular mixture thereof. This study describes th
- Yang, Lei,Neuburger, Markus,Baudoin, Olivier
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supporting information
p. 1394 - 1398
(2018/01/05)
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- A Binaphthyl-Based Scaffold for a Chiral Dirhodium(II) Biscarboxylate Ligand with α-Quaternary Carbon Centers
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A chiral dirhodium(II) paddlewheel complex has been synthesized from biscarboxylate ligands derived from BINOL, and the resulting complex has been used in enantioselective carbene/alkyne cascade reactions. The ligand design was guided by requirements of α
- Chen, Po-An,Setthakarn, Krit,May, Jeremy A.
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p. 6155 - 6161
(2017/09/15)
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- Organopromoted Selectivity-Switchable Synthesis of Polyketones
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In this work, an organopromoted metal-free pharmaceutical-oriented selectivity-switchable benzylic oxidation was developed, affording mono-, di-, and trioxygenation products, respectively, using oxygen as the oxidant under mild conditions. This process facilitates dioxygenation of 2,6-benzylic positions of heterocycles, which could be inhibited by heterocycle chelation to the metal cocatalysts. Enantiopure chiral ketones could also be prepared. The noninvolvement of transition metals and toxins avoids metal or hazardous residues, consequently ensuring a final-stage gram-scale synthesis of Lenperone.
- Liu, Jie,Hu, Kang-Fei,Qu, Jian-Ping,Kang, Yan-Biao
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supporting information
p. 5593 - 5596
(2017/10/25)
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- A new series of bipyridine based chiral organocatalysts for enantioselective Henry reaction
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A series of binaphthol based chiral organocatalysts were synthesized and applied as metal-free organocatalysts in the enantioselective Henry reaction. These organocatalysts enabled the Henry reaction with a lower concentration of catalysts at room tempera
- Ashokkumar, Veeramanoharan,Duraimurugan, Kumaraguru,Siva, Ayyanar
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p. 7148 - 7156
(2016/08/09)
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- Binaphthyl-based chiral bifunctional organocatalysts for water mediated asymmetric List-Lerner-Barbas aldol reactions
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Novel binaphthyl-based chiral bifunctional organocatalysts were designed, synthesized and successfully applied to the asymmetric List-Lerner-Barbas aldol reaction in the presence of water. These organocatalysts were found to be effective catalysts for the
- Ashokkumar, Veeramanoharan,Chithiraikumar, Chinnadurai,Siva, Ayyanar
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p. 9021 - 9032
(2016/10/07)
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- The development of new amine-amide ligands for application in Cu(II)-catalyzed enantioselective Henry reactions
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A new type of chiral tertiary amine ligand was designed and derived from l-proline and (R)-BINOL. These new chiral ligands chelated with Cu(II) showed highly catalytic efficiency in enantioselective Henry reactions. Excellent yields (up to 99%) and high enantioselectivities (up to 96% ee) were achieved for aromatic, hetero-aromatic and aliphatic aldehyde substrates, without an additional base additive or the need for air or moisture exclusion.
- Ao, Chunyan,Men, Jian,Wang, Yang,Shao, Tao,Huang, Yuanyuan,Huo, Junji,Gao, Guowei
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p. 589 - 595
(2016/07/06)
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- Intramolecularly Sulfur-Stabilized Silicon Cations with Chiral Binaphthyl Backbones: Synthesis of Three Different Motifs and Their Application in Enantioselective Diels-Alder Reactions
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The formation and 29Si NMR spectroscopic characterization of silicon cations that are intramolecularly stabilized by a dialkyl thioether are described. The chemical stability of the silicon-sulfur Lewis pair and, hence, the viability of the approach, were probed with a 2-[(alkylthio)methyl]phenyl-substituted hydrosilane as a proxy before three different motifs with chiral binaphthyl backbones were prepared in multistep sequences. The degree of shielding of the silicon atom in these cations was found to depend on the substitution pattern at the silicon atom and the ring size generated by the silicon-sulfur interaction. These sulfur-stabilized silicon cations are sufficiently reactive to promote Diels-Alder reactions of cyclohexa-1,3-diene with various dienophiles; the same set of reactions with cyclopentadiene is also reported. One of the three chiral Lewis acids induces low, but promising, enantioselectivity, and 24% ee is the highest value so far obtained with a cationic tetracoordinate silicon catalyst.
- Rohde, Volker H. G.,Müller, Maria F.,Oestreich, Martin
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p. 3358 - 3373
(2016/01/15)
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- The carbonyl group tuned electron-deficient phosphorus ligands and their application in Rhodium catalyzed arylation to aldehydes
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Acylphosphines, which could be efficiently prepared from acid chlorides and secondary phosphines, were developed as a type of carbonyl group tuned electron-deficient phosphorus ligand. They were found to be a kind of efficient ligand in Rhodium catalyzed arylation to aldehydes through accelerating the transmetalation process. Chiral acylphosphine ligands could be generated from carboxylic acids bearing the chiral framework correspondingly.
- Yang, Jiefang,Chen, Xingyu,Wang, Zhiqian
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supporting information
p. 5673 - 5675
(2015/09/15)
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- SILANE COMPOUNDS AND METHODS OF USING THEREOF
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Provided herein are silane compounds. The silane compounds can be used as organocatalysts and as sensors. Accordingly, also provided are methods of using the silane compounds described herein as catalysts. Methods of using the silane compounds described herein as catalysts can involve contacting a first organic species and a second organic species with a catalytically effective amount of a silane compound or a catalyst composition comprising a silane compound under conditions effective to form the desired product. The product can preferably be enantioenriched.
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Page/Page column 124-125
(2015/11/03)
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- Preparation and catalytic activity of BINOL-derived silanediols
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Enantiopure silanediols derived from BINOL are an innovative family of stereoselective hydrogen-bond donor (HBD) catalysts. Silanediols incorporated into a BINOL framework are attractive catalysts, as they are readily accessible and highly customizable. Structural modifications of the BINOL backbone affect the reactivity and selectivity of the silanediol catalysts in the additions of silyl ketene acetals to N-acyl isoquinolinium ions. The best results were obtained when the silanediol scaffold was substituted at the 4,4'- and 6,6'-positions. This report includes details regarding the properties of selected BINOL-based silanediol catalysts, including their acidities, binding constants, and X-ray crystal structures.
- Wieting, Joshua M.,Fisher, Thomas J.,Schafer, Andrew G.,Visco, Michael D.,Gallucci, Judith C.,Mattson, Anita E.
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p. 525 - 533
(2015/01/30)
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- Enantioselective catalytic lithiation using a chiral binaphthyl derivative as electron carrier
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The lithiation, of the secondary chloride 2, catalyzed by binaphthyl derivatives, i.e. BINAM 4, BINOL 5, BINAP 6, H8-BINAP 7, Tol-BINAP 8, 2,2'-bis(pyrrolidin-1-yl)-1,1'-binaphthalene 9, and 2,2'-dimethyl-1,1'- binaphthalene 11, in the presence of different ketones has been studied, yielding the corresponding alcohol derivatives 3 and 12-16 in moderate to good yields. Binaphthyl derivative 11 has revealed to be very active as catalyst in the lithiation process at room temperature, and has allowed the preparation of the alcohol derivatives with enantioselectivities up to 50%.
- Martinez, Regina,Pastor, Isidro M.,Yus, Miguel
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- Highly modular C1-symmetric chiral (P,N) ligands with a stereolabile P center: Experimental and theoretical studies
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An improved synthesis of a novel class of bidentate (P,N) ligands is presented, the structures of which are characterized by three distinct elements of chirality. The stereoselective installation of the elements of central chirality (at the benzylic carbon and the phosphorus atom) depends on the size of the phosphorus substituent. Thermal inversion of the phosphorus center has been studied experimentally and further correlated by DFT calculations. The potential of these ligands and the role of the phosphorus atom in the asymmetric α-arylation of aldehydes (Pd) and hydrogenation of allylic alcohols (Ir) have also been investigated. Copyright
- Humbert, Nicolas,Larionov, Evgeny,Mantilli, Luca,Nareddy, Pradeep,Besnard, Celine,Guenee, Laure,Mazet, Clement
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supporting information
p. 745 - 751
(2014/01/23)
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- Synthesis of axially chiral gold complexes and their applications in asymmetric catalyses
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Several novel chiral N-heterocyclic carbene and phosphine ligands were prepared from (S)-BINOL. Moreover, their ligated Au complexes were also successfully synthesized and characterized by X-ray crystal diffraction. A weak gold-π interaction between the Au atom and the aromatic ring in these gold complexes was identified. Furthermore, we confirmed the formation of a pair of diastereomeric isomers in NHC gold complexes bearing an axially chiral binaphthyl moiety derived from the hindered rotation around C-C and C-N bonds. In the asymmetric intramolecular hydroamination reaction most of these chiral Au(I) complexes showed good catalytic activities towards olefins tethered with a NHTs functional group to give the corresponding product in moderate yields and up to 29% ee.
- Sun, Yin-Wei,Xu, Qin,Shi, Min
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supporting information
p. 2224 - 2232
(2013/11/19)
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- Access to 2′-substituted binaphthyl monoalcohols via complementary nickel-catalyzed kumada coupling reactions under mild conditions: Key role of a P,O ligand
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Two complementary Kumada coupling methods for the conversion of monotriflated 1,1′-binaphthalene-2,2′-diol (BINOL) into 2′-substituted binaphthyl monoalcohols under mild conditions are reported. A protocol using NiCl2(dppe), in combination with
- Handa, Sachin,Mathota Arachchige, Yohan L. N.,Slaughter, Legrande M.
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p. 5694 - 5699
(2013/07/26)
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- A new BINOL-derived chiral bifunctional phosphine organocatalyst: Preparation and application in asymmetric (Aza)-morita-baylis-hillman reactions
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A new BINOL-derived chiral bifunctional phosphine has been designed and successfully prepared, which features a cyclic substructure of 1,3,5-diazaphosphinane. This chiral phosphine possesses good air stability in solid state, and it can be conveniently us
- Wang, Chunzhang,Wang, Lijun,Zeng, San,Xu, Silong,He, Zhengjie
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supporting information
p. 1548 - 1554
(2013/10/21)
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- Chiral silanediols in anion-binding catalysis
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A perfect pair: Silanediols are effective catalysts for the addition of silyl ketene acetals to N-acylisoquinolinium ions. Importantly, this is the first example of a silanediol plausibly participating in anion-binding catalysis, a relatively new direction in the field of hydrogen-bond-donor catalysis. The chiral, enantiopure C2-symmetric silanediol 1 catalyzes enantioselective transformations. Copyright
- Schafer, Andrew G.,Wieting, Joshua M.,Fisher, Thomas J.,Mattson, Anita E.
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supporting information
p. 11321 - 11324
(2013/11/06)
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- Synthesis and properties of macrocyclic diazene switch with binaphthalene unit attached via acrylamide linkers
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2,2′-Diiodo-1,1′-binaphthalene undergoes a tandem Heck reaction with methyl acrylate to afford methyl 2-(7H-dibenzo[c,g]fluoren-7-ylidene) acetate. As a consequence, the target macrocyclic diazene with binaphthalene unit attached via acrylamide linker was prepared by the stepwise building of acrylamide at a binaphthalene moiety, including the Doebner modification of the Knoevenagel condensation, and completed by oxidative macrocyclisation of aniline end-groups. Despite being an equimolar mixture of monomer and dimer, it exhibited remarkable changes in CD spectra due to reversible (E/Z) isomerisation of N=N diazene bonds upon irradiation at 365/465 nm. Although the dimer isomerises from (E) to (Z) isomer 7.4 times faster than the monomer, the latter's contribution to the change in ellipticity at 307 nm in the photostationary state is 2.4 times greater.
- Kickova, Anna,Kerner, Lukas,Putala, Martin,Horvath, Branislav
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p. 101 - 109,9
(2020/08/24)
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- CHIRAL PHOSPHINES FOR PALLADIUM-CATALYZED ASYMMETRIC ALPHA-ARYLATION OF ESTER ENOLATES TO PRODUCE TERTIARY STEREOCENTERS IN HIGH ENANTIOSELECTIVITY
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The disclosure provides new and improved methods for the Pd-catalyzed asymmetric α-arylation of ester compounds, which produce the corresponding α-aryl moiety in high enantioselectivity (generally >90% ee). The present methods utilize a palladium catalyst supported by new (R)-H8-BINOL-derived monophosphine ligands. The method is applicable to a wide variety of aryl triflate substrates having variations in both electronic and steric properties. These aryl triflate substrates react with various α-alkyl (Z)- and/or (E)-0-trimethylsilyl ketene acetals in the presence of a Pd catalyst, (R)-H8-BINOL-derived monophosphine ligand, and a mild activator, for example, LiOAC, to provide the asymmetric α-arylation of ester compounds in high ee.
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Paragraph 00133-00134
(2013/03/26)
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- Rhodium(II)-catalyzed cyclization of bis(N-tosylhydrazone)s: An efficient approach towards polycyclic aromatic compounds
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Ahead of the PAC: Polycyclic aromatic compounds (PACs) can be easily accessed by the combination of Suzuki-Miyaura cross-coupling and a [Rh 2(OAc)4]-catalyzed carbene reaction using easily available bis(N-tosylhydrazone)s as intermediates (see scheme; Ts=4-toluenesulfonyl). Copyright
- Xia, Ying,Liu, Zhenxing,Xiao, Qing,Qu, Peiyuan,Ge, Rui,Zhang, Yan,Wang, Jianbo
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supporting information; experimental part
p. 5714 - 5717
(2012/07/28)
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- Chiral aminophosphines as catalysts for enantioselective double-michael indoline syntheses
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The bisphosphine-catalyzed double-Michael addition of dinucleophiles to electron-deficient acetylenes is an efficient process for the synthesis of many nitrogencontaining heterocycles. Because the resulting heterocycles contain at least one stereogenic center, this double-Michael reaction would be even more useful if an asymmetric variant of the reaction were to be developed. Aminophosphines can also facilitate the double-Michael reaction and chiral amines are more readily available in Nature and synthetically; therefore, in this study we prepared several new chiral aminophosphines. When employed in the asymmetric double-Michael reaction between ortho-tosylamidophenyl malonate and 3-butyn-2-one, the chiral aminophosphines produced indolines in excellent yields with moderate asymmetric induction.
- Khong, San N.,Kwon, Ohyun
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scheme or table
p. 5626 - 5650
(2012/07/03)
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- Atropoisomeric (P,N) ligands for the highly enantioselective Pd-catalyzed intramolecular asymmetric α-arylation of α-branched aldehydes
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Three-in-one: A short synthetic route readily gives access to a new class of chiral (P,N) ligands characterized by three distinct elements of chirality. These ligands are highly enantioselective in the challenging Pd-catalyzed intramolecular asymmetric α-
- Nareddy, Pradeep,Mantilli, Luca,Guenee, Laure,Mazet, Clement
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supporting information; scheme or table
p. 3826 - 3831
(2012/06/01)
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- Pd-catalyzed asymmetric allylic alkylation of indoles and pyrroles by chiral alkene-phosphine ligands
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Chemical equations presented. A variety of chiral binaphthyl-based terminal-alkene-phosphine hybrid ligands were synthesized in four steps with (S)-BINOL as a starting material and utilized for the Pd-catalyzed enantioselective allylic alkylations of indo
- Cao, Ziping,Liu, Yilin,Liu, Zhaoqun,Feng, Xiangqing,Zhuang, Minyang,Du, Haifeng
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supporting information; experimental part
p. 2164 - 2167
(2011/07/07)
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- Process research on the asymmetric hydrogenation of a benzophenone for developing the manufacturing process of the squalene synthase inhibitor TAK-475
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A practical synthetic method for the synthesis of the chiral benzhydrol 8, which is the key intermediate of the squalene synthase inhibitor TAK-475 (1), has been developed. The method, via asymmetric hydrogenation of the benzophenone 7, employed Noyori's ruthenium precatalyst of the type [RuCl 2(diphosphine)(diamine). We focused on tuning of the chiral diphosphine, and have discovered a novel ligand, DADMP-BINAP (18c), for the catalyst that has allowed reduction of the operating pressure in the asymmetric hydrogenation. The precatalyst containing 18c performed effectively at low hydrogen pressure (1 MPa) with sufficient enantioselectivity, and the result enabled us to successfully obtain enantiomerically pure 8 on a multikilogram scale.
- Goto, Mitsutaka,Konishi, Takahiro,Kawaguchi, Shinji,Yamada, Masatoshi,Nagata, Toshiaki,Yamano, Mitsuhisa
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scheme or table
p. 1178 - 1184
(2011/12/16)
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- BINAP versus BINAP(O) in asymmetric intermolecular Mizoroki-Heck reactions: Substantial effects on selectivities
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2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) was employed as chiral ligand in the enantioselective intermolecular Mizoroki-Heck reaction, whereas the use of cognate BINAP(O) (monooxidized BINAP) is unprecedented. The regio- and enantioselectivity of the arylation of representative cyclic alkenes changes dramatically in the presence of hemilabile BINAP(O) instead of BINAP. The arylation of 2,3-dihydrofuran is perfectly regiodivergent (98:2 versus 0:100) and the arylation of cyclopentene is only enantioselective with BINAP(O) [60 versus 10% enantiomeric excess (ee)]. Use of [Pd2(dba)3]·dba (dba=dibenzylideneacetone) instead of Pd(OAc)2 produces as high as 86% ee in the arylation of cyclopentene.
- Woeste, Thorsten H.,Oestreich, Martin
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supporting information; experimental part
p. 11914 - 11918
(2011/11/29)
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- An enantioselective, intermolecular α-arylation of ester enolates to form tertiary stereocenters
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In transition-metal catalyzed, asymmetric α-arylation of carbonyl compounds, formation of tertiary centers with high enantioselectivity is a longstanding problem, due to easy enolization of the monoarylation products. Herein, we report such examples using a palladium catalyst supported by a new, (R)-H8-BINOL-derived monophosphine. Silyl ketene acetals, together with a weakly basic activator, were used as equivalents of ester anions, and they reacted smoothly with aryl triflates in excellent enantiomeric excess (ee). The usefulness of the reaction was demonstrated in a gram-scale synthesis of (S)-Naproxen in 92% ee.
- Huang, Zhiyan,Liu, Zheng,Zhou, Jianrong
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supporting information; experimental part
p. 15882 - 15885
(2011/11/13)
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- Synthesis of P-stereogenic BINAP bissulfide analogues
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A synthetic route to BINAP disulfide analogues with chirality on one of the phosphorus atoms was developed. The synthesis of these ligands was achieved by step-wise palladium and nickel-catalysed coupling reactions of the precursor binaphthyl triflate wit
- Rafter, Eoin,Muldoon, Jimmy,Mueller Bunz, Helge,Gilheany, Declan G.
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scheme or table
p. 1680 - 1686
(2012/01/03)
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- COMPOSITIONS AND METHODS FOR CYCLOFRUCTANS AS SEPARATION AGENTS
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The present invention relates to derivatized cyclofructan compounds, compositions comprising derivatized cyclofructan compounds, and methods of using compositions comprising derivatized cyclofructan compounds for chromatographic separations of chemical species, including enantiomers. Said compositions may comprise a solid support and/or polymers comprising derivatized cyclofructan compounds.
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Page/Page column 45-49; 56
(2010/12/31)
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- Electrophilic trifluoromethylation of primary phosphines: Synthesis of a P -bis(trifluoromethyl) derivative of BINAP
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The new chiral diphosphine ligand (R)-(2′-(bis(trifluoromethyl) phosphino)-1,1′-binaphthyl-2-yl)diphenylphosphine (2), which contains a bis(trifluoromethyl)phosphine group, was prepared in five steps from (R)-BINOL (5). As a key transformation, the unprecedented electrophilic double trifluoromethylation of the primary phosphine 8 was achieved using the hypervalent iodine trifluoromethylation reagent 1-trifluoromethyl-1,2- benziodoxol-3-(1H)-one (1), derived from o-iodobenzoic acid. The palladium dichloride complex of this ligand (10) shows the P(CF3)2 group with a high degree of pyramidalization at the P atom and a relatively short Pd?P bond (2.2230(4) A), both features being indicative of the strong s-character of the phosphorus lone pair.
- Armanino, Nicolas,Koller, Raffael,Togni, Antonio
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scheme or table
p. 1771 - 1777
(2010/06/17)
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- Multistep microchemical synthesis enabled by microfluidic distillation
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(Figure Presented) Microchemical solvent switch: A continuous-flow, multistep Heck synthesis was made possible by integrating microreactors, liquid-liquid extraction, and microfluidic distillation. The microfluidic distil-lation enabled solvent exchange from CH2CI2 in the first reaction step to N,Ndimethylformamide (DMF) in the final reaction step.
- Hartman, Ryan L.,Naber, John R.,Buchwald, Stephen L.,Jensen, Klavs F.
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experimental part
p. 899 - 903
(2010/06/11)
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- Synthetic access to a novel binaphthyl ligand bearing a phosphine and a triazole donor site
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The combination of a diphenylphospinyl and a triazol-3-yl unit was realized for the first time at a 1,1′-binaphthyl backbone. This novel type of P, N-ligand is accessible as an enantiomerically pure compound in just a few steps. First experiments on the coordination chemistry with palladium(II) chloride have been carried out. A series of intermediates and a binuclear palladium(II) complex could be characterized by X-ray crystal structure analysis.
- May, Claudia,Sun, Yu,Wolmershaeuser, Gotthelf,Thiel, Werner R.
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scheme or table
p. 1438 - 1448
(2010/07/04)
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- Binaphthalene-derived iminium salt catalysts for highly enantioselective asymmetrie epoxidation
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Enantiomerically enriched epoxides are useful intermediates that have found many applications in asymmetric synthesis, and development of efficient catalysts for asymmetric epoxidation has received considerable attention, In this manuscript we describe the design, preparation, and use of new highly selective imlnium salt organocatalysts for asymmetric epoxidation, based around a chiral binaphthalene motif coupled with a chiral substituted dioxane moiety. The new catalysts have been tested in the catalytic asymmetric epoxidation of unfunctionalized alkenes, and provide up to 95 % ee.
- Bulman Page, Philip C.,Buckley, Benjamin R.,Farah, Mohamed M.,John Blacker
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experimental part
p. 3413 - 3426
(2011/02/26)
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- Matching and mismatching effects of hybrid chiral biaxial bisphosphine ligands in enantioselective hydrogenation of ketoesters
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A study was conducted to demonstrate matching and mismatching of hybrid chiral biaxial bisphosphine ligands in enantioselective hydrogenation of ketoesters. A novel class of conformationally rigid Cn-TunePhos was developed by introducing a bridge with variable length to link the chiral atropisometic biaryl groups. The conformationally rigid Cn-TunePhos was introduce to investigate the synthesis and use of new chiral biophosphine ligands in asymmetric catalysis. A strategy was introduced for the synthesis of a pair of diastereoisomeric forms of ligands 1, 2, and an analogous ligand 3 to assess the effects of stereochemical matching and mismatching interactions upon the structural and catalytic properties of the corresponding ruthenium complexes. Their applications in highly efficient Ru-catalyzed asymmetric hydrogenation for the enantioselective synthesis of α- and β-hydroxy acid derivatives were also explored.
- Sun, Xianfeng,Li, Wei,Zhou, Le,Zhang, Xumu
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scheme or table
p. 7302 - 7305
(2010/03/24)
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- Development of new HPLC chiral stationary phases based on native and derivatized cyclofructans
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An unusual class of chiral selectors, cyclofructans, is introduced for the first time as bonded chiral stationary phases. Compared to native cyclofructans (CFs), which have rather limited capabilities as chiral selectors, aliphatic-and aromatic-functionalized CF6s possess unique and very different enantiomeric selectivities. Indeed, they are shown to separate a very broad range of racemic compounds. In particular, aliphatic-derivatized CF6s with a low substitution degree baseline separate all tested chiral primary amines. It appears that partial derivatization on the CF6 molecule disrupts the molecular internal hydrogen bonding, thereby making the core of the molecule more accessible. In contrast, highly aromaticfunctionalized CF6 stationary phases lose most of the enantioselective capabilities toward primary amines, however they gain broad selectivity for most other types of analytes. This class of stationary phases also demonstrates high "loadability" and therefore has great potential for preparative separations. The variations in enantiomeric selectivity often can be correlated with distinct structural features of the selector. The separations occur predominantly in the presence of organic solvents.
- Sun, Ping,Wang, Chunlei,Breitbach, Zachary S.,Zhang, Ying,Armstrong, Daniel W.
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experimental part
p. 10215 - 10226
(2010/05/01)
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- Development of a new class of C1-symmetric bisphosphine ligands for rhodium-catalyzed asymmetric hydrogenation
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A new class of C1-symmetric bisphosphine ligands with three hindered quadrants have been obtained through facile synthesis from chiral BINOL derivatives. Their rhodium complexes have exhibited high enantioselectivities (up to 98% ee) in the asy
- Dai, Qian,Li, Wei,Zhang, Xumu
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p. 6943 - 6948
(2008/12/20)
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- Separation And Manipulation Of A Chiral Object
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Among other things, to cause directional motion of chiral objects in a mixture in a chamber, a field is rotated relative, to a chamber to cause rotation of the chiral objects. The rotation of the objects causes them to move directionally based on their chirality.
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Page/Page column 14
(2008/12/04)
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