- Stereocontrolled synthesis of 1,2- and 1,3-diamine building blocks from aziridine aldehyde dimers
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Vicinal aziridine-containing diamines have been obtained with high syn-stereoselectivity from readily available aziridine aldehyde dimers in the Petasis borono-Mannich reaction. Subsequent solvent- and/or nucleophile- dependent ring-opening of the aziridine ring yields functionalized 1,2- and 1,3-diamines with high regioselectivity. The ring opening is also influenced by the substitution at the C3 position of the aziridine. A mechanistic rationale for the highly syn-selective three-component reaction is proposed.
- Liew, Sean K.,He, Zhi,St. Denis, Jeffrey D.,Yudin, Andrei K.
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Read Online
- Copper-Catalyzed Alkynylation of Benzylic C-H Bonds with Alkynylboronic Esters
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We report a simple method for copper-catalyzed benzylic C-H alkynylation that uses alkynylboronic esters as nucleophilic coupling partners. The catalytic system is readily available and the reaction takes place under mild conditions. Different substrates for the C-H functionalization, as well as various alkynylboronic ester nucleophiles, were evaluated. Finally, three examples of enantioselective C-H alkynylations are presented.
- Buendia, Mikkel B.,Balin, Jan-Georges J.,Andersen, Mette E.,Lian, Zhong,Kramer, Soren
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Read Online
- Monosubstituted 3,3-Difluorocyclopropenes as Bench-Stable Reagents: Scope and Limitations
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A general approach to gem-difluorocyclopropenes synthesis based on the reaction of alkynes with Ruppert-Prakash reagent is reported. The proposed method is evaluated for the synthesis of a wide difluorocyclopropenes scope based on their bench lifespan and hydrolytic stability. The tolerance of the method for common functional groups was shown. Previously unavailable difluorocyclopropenes substituted with aliphatic were prepared using the proposed procedure. The retain of stability was proven by the multigram scale synthesis and further storage in the temperature interval ?78 to ?4 °C over a year. This makes them attractive building blocks and intermediates for organic synthesis. The reasons for dropping stability were defined. The relations between the structure of the substituents and the stability of the difluorocyclopropene ring were determined and discussed.
- Nosik, Pavel S.,Pashko, Mykola O.,Poturai, Andrii S.,Kvasha, Denys A.,Pashenko, Alexander E.,Rozhenko, Alexander B.,Suikov, Sergiy,Volochnyuk, Dmitriy M.,Ryabukhin, Sergey V.,Yagupolskii, Yurii L.
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p. 6604 - 6615
(2021/12/08)
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- Aluminium-Catalyzed C(sp)?H Borylation of Alkynes
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Historically used in stoichiometric hydroalumination chemistry, recent advances have transformed aluminium hydrides into versatile catalysts for the hydroboration of unsaturated multiple bonds. This catalytic ability is founded on the defining reactivity of aluminium hydrides with alkynes and alkenes: 1,2-hydroalumination of the unsaturated π-system. This manuscript reports the aluminium hydride catalyzed dehydroborylation of terminal alkynes. A tethered intramolecular amine ligand controls reactivity at the aluminium hydride centre, switching off hydroalumination and instead enabling selective reactions at the alkyne C?H σ-bond. Chemoselective C?H borylation was observed across a series of aryl- and alkyl-substituted alkynes (21 examples). On the basis of kinetic and density functional theory studies, a mechanism in which C?H borylation proceeds by σ-bond metathesis between pinacolborane (HBpin) and alkynyl aluminium intermediates is proposed.
- Willcox, Dominic R.,De Rosa, Daniel M.,Howley, Jack,Levy, Abigail,Steven, Alan,Nichol, Gary S.,Morrison, Carole A.,Cowley, Michael J.,Thomas, Stephen P.
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supporting information
p. 20672 - 20677
(2021/08/20)
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- Method for removing hydroboration of aluminum chloride catalytic terminal group alkyne
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The invention discloses a hydroboration method of an aluminum chloride catalytic terminal group alkyne, and belongs to the technical field of boronation of terminal alkynes. To the method, the terminal group alkyne is added into the aluminum chloride with
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Paragraph 0063-0065
(2021/10/16)
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- ZnBr2-Catalyzed Dehydrogenative Borylation of Terminal Alkynes
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The simple, commercially available ZnBr2 has been successfully employed as a highly efficient and chemoselective catalyst for the dehydrogenative borylation of terminal alkynes with HBpin under mild conditions. It shows a good tolerance toward various functional groups such as aryl, alkyl, heteroaryl, etc. The plausible reaction mechanism has been investigated based on the corresponding stoichiometric experiments and DFT calculations.
- Luo, Man,Qin, Yi,Chen, Xi,Xiao, Qian,Zhao, Binlin,Yao, Weiwei,Ma, Mengtao
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p. 16666 - 16674
(2021/11/18)
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- Ni-Catalyzed Cyclization of Enynes and Alkynylboronates: Atom-Economical Synthesis of Boryl-1,4-dienes
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We report a novel atom-economical Ni-catalyzed cyclization reaction of enynes with alkynylboronates. The reaction employs a non-expensive Ni salt, a phosphine-based ligand and easy-handling alkynylboronates as boron–carbon source. The reaction provides co
- Cabrera-Lobera, Natalia,Quirós, M. Teresa,Bu?uel, Elena,Cárdenas, Diego J.
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supporting information
p. 14512 - 14516
(2019/11/11)
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- Iron-Catalyzed Dehydrogenative Borylation of Terminal Alkynes
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The catalytic system based on Fe(OTf)2 (2.5 mol%) and DABCO (1 mol%) selectively promotes the dehydrogenative borylation of both aromatic and aliphatic terminal alkynes to afford alkynylboronate derivatives in the presence of 1 equiv. of pinaco
- Wei, Duo,Carboni, Bertrand,Sortais, Jean-Baptiste,Darcel, Christophe
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supporting information
p. 3649 - 3654
(2018/09/14)
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- Copper-catalyzed dehydrogenative borylation of terminal alkynes with pinacolborane
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LCuOTf complexes [L = cyclic (alkyl)(amino)carbenes (CAACs) or N-heterocyclic carbenes (NHCs)] selectively promote the dehydrogenative borylation of C(sp)-H bonds at room temperature. It is shown that σ,π-bis(copper) acetylide and copper hydride complexes are the key catalytic species.
- Romero, Erik A.,Jazzar, Rodolphe,Bertrand, Guy
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p. 165 - 168
(2016/12/30)
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- SUBSTITUTED BICYCLIC COMPOUNDS AS BROMODOMAIN INHIBITORS
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The present disclosure relates to substituted bicyclic compounds, which are useful for inhibition of BET protein function by binding to bromodomains, and their use in therapy.
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Page/Page column 0174
(2016/07/05)
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- BICYCLIC HETEROCYCLIC DERIVATIVES AS BROMODOMAIN INHIBITORS
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The present disclosure provides bicyclic heterocyclic derivatives of formula (I), which may be therapeutically useful, more particularly as bromodomain inhibitors; (I), in which R1, R2, R3, R4, L1, L2, Cy1, Cy2, X, n, and dotted line have the same meaning given in the specification, and pharmaceutically acceptable salts or pharmaceutically acceptable stereoisomers thereof that are useful in the treatment and prevention of diseases or disorders, in particular their use in diseases or disorders associated as bromodomain inhibitors. The present disclosure also provides preparation of compounds and pharmaceutical formulations comprising at least one of bicyclic heterocyclic derivatives of formula (I), together with a pharmaceutically acceptable carrier, diluent, or excipient.
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Paragraph 0213
(2017/04/04)
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- Ligand survey results in identification of PNP pincer complexes of iridium as long-lived and chemoselective catalysts for dehydrogenative borylation of terminal alkynes
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Following the report on the successful use of SiNN pincer complexes of iridium as catalysts for dehydrogenative borylation of terminal alkynes (DHBTA) to alkynylboronates, this work examined a wide variety of related pincer ligands in the supporting role in DHBTA. The ligand selection included both new and previously reported ligands and was developed to explore systematic changes to the SiNN framework (the 8-(2-diisopropylsilylphenyl)aminoquinoline). Surprisingly, only the diarylamido/bis(phosphine) PNP system showed any DHBTA reactivity. The specific PNP ligand (bearing two diisopropylphosphino side donors) used in the screen showed DHBTA activity inferior to SiNN. However, taking advantage of the ligand optimization opportunities presented by the PNP system via the changes in the substitution at phosphorus led to the discovery of a catalyst whose activity, longevity, and scope far exceeded that of the original SiNN archetype. Several Ir complexes were prepared in a model PNP system and evaluated as potential intermediates in the catalytic cycle. Among them, the (PNP)Ir diboryl complex and the borylvinylidene complex were shown to be less competent in catalysis and thus likely not part of the catalytic cycle.
- Lee, Chun-I,Demott, Jessica C.,Pell, Christopher J.,Christopher, Alyson,Zhou, Jia,Bhuvanesh, Nattamai,Ozerov, Oleg V.
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p. 6572 - 6582
(2015/10/28)
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- BICYCLIC HETEROCYCLIC DERIVATIVES AS BROMODOMAIN INHIBITORS
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The present invention provides bicyclic heterocyclic derivatives of formula (I), which may be therapeutically useful, more particularly as bromodomain inhibitors; (I), in which R1, R2, R3, R4, L1, L2, Cy1, Cy2, X, n and dotted line are have the same meaning given in the specification, and pharmaceutically acceptable salts or pharmaceutically acceptable stereoisomers thereof that are useful in the treatment and prevention of diseases or disorder, in particular their use in diseases or disorder associated as bromodomain inhibitors. The present invention also provides preparation of the compounds and pharmaceutical formulations comprising at least one of bicyclic heterocyclic derivatives of formula (I), together with a pharmaceutically acceptable carrier, diluent or excipient therefor.
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Page/Page column 52
(2015/07/23)
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- Ag(I)-catalyzed C-H borylation of terminal alkynes
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An efficient Ag(I)-catalyzed borylation method of terminal alkynes is reported. The obtained borylated alkynes are shown to engage in C-Br, C-CN, C-N, and C-C bond formation with various reaction partners. Meanwhile the Ag(I) catalyst could be regenerated in the presence of PPh3 and BF3.
- Hu, Jiu-Rong,Liu, Lin-Hai,Hu, Xin,Ye, Hong-De
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p. 5815 - 5819
(2015/03/30)
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- Catalytic dehydrogenative borylation of terminal alkynes by a SiNN pincer complex of iridium
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Compounds with carbon-boron bonds are versatile intermediates for building more complex molecules via the elaboration of the carbon-boron bonds into other carbon-element bonds. The synthesis of carbon-boron bonds by catalytic dehydrogenative borylation of carbon-hydrogen bonds with dialkoxyboranes (RO)2BH is particularly attractive. It has been demonstrated for a variety of carbon-hydrogen bond types but not for the C(sp)-H bonds of terminal alkynes, for which hydroboration of the triple bond is a competing process. We report a new iridium catalyst that is strictly chemoselective for C-H borylation of terminal alkynes. The key to the success of this catalyst appears to be the new ancillary SiNN pincer ligand that combines amido, quinoline, and silyl donors and gives rise to structurally unusual Ir complexes. A variety of terminal alkynes (RC≡C-H) can be converted to their alkynylboronates (RC≡C-Bpin, where pin = pinacolate) in high yield and purity within minutes at ambient temperature.
- Lee, Chun-I,Zhou, Jia,Ozerov, Oleg V.
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supporting information
p. 3560 - 3566
(2013/04/23)
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- Scalable synthesis of functionalised 2-pyridones via [4+2] cycloaddition reactions of 2-pyrazinones and alkynylboronates
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The multigram synthesis of N-protected 2-pyridone boronic acid derivatives via a [4+2] cycloaddition of alkynylboronates with 2-pyrazinones is presented. The reactions are highly chemoselective, and generally highly regioselective although trimethylsilyl-substituted alkynylboronates have proven to be an exception. Nonetheless, in this latter case, separation of regioisomers was successfully accomplished via high performance counter-current chromatography allowing isolation of analytically pure 2-pyridones. Further derivatisations of trimethylsilyl-substituted 2-pyridone boronates were performed providing access to a selection of functionalised scaffolds.
- Harker, Wesley R.R.,Delaney, Patrick M.,Simms, Michael,Tozer, Matthew J.,Harrity, Joseph P.A.
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p. 1546 - 1552
(2013/02/25)
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- 2-PYRIDYL CARBOXAMIDE-CONTAINING SPLEEN TYROSINE KINASE (SYK) INHIBITORS
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The invention provides certain 2-pyridyl carboxamide-containing compounds of the Formula (I) or pharmaceutically acceptable salts thereof, wherein A and B are as defined herein. The invention also provides pharmaceutical compositions comprising such compounds, and methods of using the compounds for treating diseases or conditions mediated by Spleen Tyrosine Kinase (Syk) kinase.
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Paragraph 00253
(2013/04/24)
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- Synthesis and characterization of platinum(II)-Bis(boryl) catalyst precursors for diboration of alkynes and diynes: Molecular structures of cis-[(PPh3)2Pt(B-4-Butcat)2], cis-[(PPh3)2Pt(Bcat)2], cis-[(dppe)Pt(Bcat)2], cis-[(dppb)Pt(Bcat)2]
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The reactions of the B-B-bonded compounds B2(cat)2 (cat = 1,2-O2C6H4) (1a), B2(4-But-cat)2 (1b), and B2(OCMe2CMe2O)2 (1c) with the Pt(0)-bis(phosphine) complex [(PPh3)2Pt(η-C2H4)] (4) via oxidative addition of the B-B bond yield cis-bis(boryl) Pt(II) complexes. The molecular structures of cis-[(PPh3)2Pt(Bcat)2]·C 6D6 (3a) and cis-[(PPh3)2Pt(B-4-Butcat)2] (3b) were determined by single-crystal X-ray diffraction. Reaction of 3a with 1 equiv of the bidentate phosphine dppe (Ph2PCH2CH2PPh2) or dppb (Ph2P(CH2)4PPh2) proceeds smoothly in toluene to give cis-[(dppe)Pt(Bcat)2] (5a) and cis-[(dppb)Pt(Bcat)2] (5b), respectively, which have also been characterized by X-ray diffraction. Compounds 3a,b and 4 are highly active catalyst precursors for the diboration of alkynes and 1,3-diynes. X-ray crystal structures of (E)-(4-MeOC6H4)C(Bcat)=CH(Bcat) (10c), (Z)-(C6H5)C(Bcat)=C(C6H5)(Bcat) (10e), and (Z,Z)-(4-MeOC6H4)C(Bcat)=C(Bcat)C(Bcat)=C(4-MeOC 6H4)(Bcat) (14a) confirm the cis stereochemistry of the boron substituents in three representative cases, namely, products of the catalyzed diboration of the terminal alkyne 4-MeOC6H4C=CH, the internal alkyne PhC=CPh, and the tetraboration of the diyne 4,4′-MeOC6H4C=CC=CC6H4OMe. The presence of the C=CSiMe3 moiety in catalytic reactions gives rise to additional products other than those derived from the diboration of the alkyne group. Metathetical reactions involving the diboron reagent and products derived from C-Si bond cleavage give rise to novel tris(boronate esters) as a result of the subsequent diboration of the C=CB(OR2) moieties formed by this competing process. The absence of catalytic activity using compound 5a, the extremely low activity of 5b, and the strong decrease in activity of 3b in the presence of added PPh3 suggests that phosphine dissociation is a critical step in the catalytic pathway.
- Lesley, Gerry,Nguyen, Paul,Taylor, Nicholas J.,Marder, Todd B.,Scott, Andrew J.,Clegg, William,Norman, Nicholas C.
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p. 5137 - 5154
(2008/10/08)
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