- Carbon Dioxide as a Directing Group for C-H Functionalization Reactions Involving Lewis Basic Amines, Alcohols, Thiols, and Phosphines for the Synthesis of Compounds
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Methods of synthesizing compounds using CO2 as a directing group for C—H functionalization, and compounds made thereby, are described.
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Paragraph 0092; 0096; 0101
(2019/07/03)
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- Palladium-Catalyzed C(sp3)?H Arylation of Primary Amines Using a Catalytic Alkyl Acetal to Form a Transient Directing Group
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C?H Functionalization of amines is a prominent challenge due to the strong complexation of amines to transition metal catalysts, and therefore typically requires derivatization at nitrogen with a directing group. Transient directing groups (TDGs) permit C?H functionalization in a single operation, without needing these additional steps for directing group installation and removal. Here we report a palladium catalyzed γ-C?H arylation of amines using catalytic amounts of alkyl acetals as transient activators (e.g. commercially available (2,2-dimethoxyethoxy)benzene). This simple additive enables arylation of amines with a wide range of aryl iodides. Key structural features of the novel TDG are examined, demonstrating an important role for the masked carbonyl and ether functionalities. Detailed kinetic (RPKA) and mechanistic investigations determine the order in all reagents, and identify cyclopalladation as the turnover limiting step. Finally, the discovery of an unprecedented off-cycle free-amine directed ?-cyclopalladation of the arylation product is reported.
- St John-Campbell, Sahra,Ou, Alex K.,Bull, James A.
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p. 17838 - 17843
(2018/11/23)
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- Carbon Dioxide-Mediated C(sp3)-H Arylation of Amine Substrates
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Elaborating amines via C-H functionalization has been an important area of research over the past decade but has generally relied on an added directing group or sterically hindered amine approach. Since free-amine-directed C(sp3)-H activation is still primarily limited to cyclization reactions and to improve the sustainability and reaction scope of amine-based C-H activation, we present a strategy using CO2 in the form of dry ice that facilitates intermolecular C-H arylation. This methodology has been used to enable an operationally simple procedure whereby 1° and 2° aliphatic amines can be arylated selectively at their γ-C-H positions. In addition to potentially serving as a directing group, CO2 has also been demonstrated to curtail the oxidation of sensitive amine substrates.
- Kapoor, Mohit,Liu, Daniel,Young, Michael C.
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supporting information
p. 6818 - 6822
(2018/05/31)
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- Stable Zero-Valent Nickel Nanoparticles in Glycerol: Synthesis and Applications in Selective Hydrogenations
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Small (mean diameter, ca. 1.2 nm) and well-dispersed zero-valent nickel nanoparticles (NiNPs) stabilized by cinchona-based alkaloids and TPPTS (tris(3-sulfophenyl)phosphine trisodium salt), were synthesized from the organometallic precursor [Ni(cod)2] in neat glycerol under hydrogen pressure. NiNPs were fully characterized ((HR)-TEM, EDX, XPS, XRD, IR, magnetization), both at solid state and directly from the corresponding colloidal solutions in glycerol due to its negligible vapour pressure. NiNPs dispersed in glycerol were applied in hydrogenation reactions, in particular in semihydrogenation of alkynes to give (Z)-alkenes under satisfactory conditions (3 bar H2, 1 mol% Ni, 100 °C), showing remarkable activity and selectivity. The catalytic phase was recycled at least ten times without loss of activity, affording in each case metal-free organic products. Other functional groups such as nitro, nitrile and formyl groups were efficiently hydrogenated to the corresponding anilines, benzylamines and benzylalcohols respectively (77–95% yields). (Figure presented.).
- Reina, Antonio,Favier, Isabelle,Pradel, Christian,Gómez, Montserrat
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p. 3544 - 3552
(2018/08/01)
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- cis-2,5-dicyanopyrrolidine inhibitors of dipeptidyl peptidase IV: Synthesis and in vitro, in vivo, and x-ray crystallographic characterization
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Inhibitors of the glucagon-like peptide-1 (GLP-1) degrading enzyme dipeptidyl peptidase IV (DPP-IV) have been shown to be effective treatments for type 2 diabetes in animal models and in human subjects. A novel series of cis-2,5-dicyanopyrrolidine α-amino amides were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-IV) for the treatment of type 2 diabetes. 1-({[1-(Hydroxymethyl)cyclopentyl]amino}-acetyl)pyrrolidine-2,5-cis- dicarbonitrile (1c) is an achiral, slow-binding (time-dependent) inhibitor of DPP-IV that is selective for DPP-IV over other DPP isozymes and proline specific serine proteases, and which has oral bioavailability in preclinical species and in vivo efficacy in animal models. The mode of binding of the cis-2,5-dicyanopyrrolidine moiety was determined by X-ray crystallography. The hydrochloride salt of 1c was further profiled for development as a potential new treatment for type 2 diabetes.
- Wright, Stephen W.,Ammirati, Mark J.,Andrews, Kim M.,Brodeur, Anne M.,Danley, Dennis E.,Doran, Shawn D.,Lillquist, Jay S.,McClure, Lester D.,McPherson, R. Kirk,Orena, Stephen J.,Parker, Janice C.,Polivkova, Jana,Qiu, Xiayang,Soeller, Walter C.,Soglia, Carolyn B.,Treadway, Judith L.,VanVolkenburg, Maria A.,Wang, Hong,Wilder, Donald C.,Olson, Thanh V.
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p. 3068 - 3076
(2007/10/03)
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- Methods and compositions for treating amyloid-related diseases
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Methods, compounds, pharmaceutical compositions and kits are described for treating or preventing amyloid-related disease.
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Page/Page column 151-152
(2010/11/24)
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- HYDROXYETHYLAMINE DERIVATIVES FOR THE TREATMENT OF ALZHEIMER'S DISEASE
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The present invention relates to novel hydroxyethylamine compounds of formula (I): (I) having Asp2 (-secretase, BACE1 or Memapsin) inhibitory activity, processes for their preparation, to compositions containing them and to their use in the treatment of diseases characterised by elevated-amyloid levels or-amyloid deposits, particularly Alzheimer's disease.
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