- Cu(II)-Catalyzed Construction of Heterobiaryls using 1-Diazonaphthoquinones: A General Strategy for the Synthesis of QUINOX and Related P,N Ligands
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An efficient and straightforward method was developed for the synthesis of heterobiaryls using easily available N-oxides and diazonaphthoquinones under cheap Cu(II) catalysis. The developed method offered QUINOX and related congeners in a simple manner. A wide scope of important heterobiaryls was achieved with high site selectivity. The synthesized naphthols were transformed into the privileged related P,N ligands. Suitable resolution methods can directly afford the corresponding axially chiral heterobiaryls.
- Biswas, Aniruddha,Pan, Subarna,Samanta, Rajarshi
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supporting information
p. 1631 - 1636
(2022/03/14)
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- Ruthenium-Catalyzed Dehydrogenation Through an Intermolecular Hydrogen Atom Transfer Mechanism
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The direct dehydrogenation of alkanes is among the most efficient ways to access valuable alkene products. Although several catalysts have been designed to promote this transformation, they have unfortunately found limited applications in fine chemical synthesis. Here, we report a conceptually novel strategy for the catalytic, intermolecular dehydrogenation of alkanes using a ruthenium catalyst. The combination of a redox-active ligand and a sterically hindered aryl radical intermediate has unleashed this novel strategy. Importantly, mechanistic investigations have been performed to provide a conceptual framework for the further development of this new catalytic dehydrogenation system.
- Huang, Lin,Bismuto, Alessandro,Rath, Simon A.,Trapp, Nils,Morandi, Bill
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supporting information
p. 7290 - 7296
(2021/03/01)
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- Potassium tert-Butoxide-Promoted Acceptorless Dehydrogenation of N-Heterocycles
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Potassium tert-butoxide-promoted acceptorless dehydrogenation of N-heterocycles was efficiently realized for the generation of N-heteroarenes and hydrogen gas under transition-metal-free conditions. In the presence of KOtBu base, a variety of six- and five-membered N-heterocyclic compounds efficiently underwent acceptorless dehydrogenation to afford the corresponding N-heteroarenes and H2 gas in o-xylene at 140 °C. The present protocol provides a convenient route to aromatic nitrogen-containing compounds and H2 gas. (Figure presented.).
- Liu, Tingting,Wu, Kaikai,Wang, Liandi,Yu, Zhengkun
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supporting information
p. 3958 - 3964
(2019/08/01)
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- Efficient acceptorless photo-dehydrogenation of alcohols and: N -heterocycles with binuclear platinum(ii) diphosphite complexes
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Although photoredox catalysis employing Ru(ii) and Ir(iii) complexes as photocatalysts has emerged as a versatile tool for oxidative C-H functionalization under mild conditions, the need for additional reagents acting as electron donor/scavenger for completing the catalytic cycle undermines the practicability of this approach. Herein we demonstrate that photo-induced oxidative C-H functionalization can be catalysed with high product yields under oxygen-free and acceptorless conditions via inner-sphere atom abstraction by binuclear platinum(ii) diphosphite complexes. Both alcohols (51 examples), particularly the aliphatic ones, and saturated N-heterocycles (24 examples) can be efficiently dehydrogenated under light irradiation at room temperature. Regeneration of the photocatalyst by means of reductive elimination of dihydrogen from the in situ formed platinum(iii)-hydride species represents an alternative paradigm to the current approach in photoredox catalysis.
- Zhong, Jian-Ji,To, Wai-Pong,Liu, Yungen,Lu, Wei,Che, Chi-Ming
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p. 4883 - 4889
(2019/05/16)
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- Acceptorless Dehydrogenation of N-Heterocycles and Secondary Alcohols by Ru(II)-NNC Complexes Bearing a Pyrazoyl-indolyl-pyridine Ligand
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Ruthenium(II) hydride complexes bearing a pyrazolyl-(2-indol-1-yl)-pyridine ligand were synthesized and structurally characterized by NMR analysis and X-ray single crystal crystallographic determinations. These complexes efficiently catalyzed acceptorless dehydrogenation of N-heterocycles and secondary alcohols, respectively, exhibiting highly catalytic activity with a broad substrate scope. The present work has established a strategy to construct highly active transition metal complex catalysts and provides an atom-economical and environmentally benign protocol for the synthesis of aromatic N-heterocyclic compounds and ketones.
- Wang, Qingfu,Chai, Huining,Yu, Zhengkun
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p. 584 - 591
(2018/03/08)
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- Dehydrogenation of Nitrogen Heterocycles Using Graphene Oxide as a Versatile Metal-Free Catalyst under Air
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Graphene oxide (GO) has been developed as an inexpensive, environmental friendly, metal-free carbocatalyst for the dehydrogenation of nitrogen heterocycles. Valuable compounds, such as quinoline, 3,4-dihydroisoquinoline, quinazoline, and indole derivatives, have been successfully used as substrates. The investigation of various oxygen-containing molecules with different conjugated systems indicated that both the oxygen-containing groups and large π-conjugated system in GO sheets are essential for this reaction. (Figure presented.).
- Zhang, Jingyu,Chen, Shiya,Chen, Fangfang,Xu, Wensheng,Deng, Guo-Jun,Gong, Hang
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supporting information
p. 2358 - 2363
(2017/07/22)
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- Acceptorless and base-free dehydrogenation of alcohols and amines using ruthenium-hydride complexes
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An efficient, operatively simple, acceptorless, and base-free dehydrogenation of secondary alcohols and nitrogen-containing heterocyclic compounds was achieved by using readily available ruthenium hydride complexes as precatalysts. The complex RuH2(CO)(PPh3)3 (1) and Shvo's complex (2) showed excellent activities for the dehydrogenation of secondary alcohols and nitrogen containing heterocycles. In addition to complexes 1 and 2, the complex RuH2(PPh3)4 (3) also showed moderate to excellent activity for the acceptorless dehydrogenation of nitrogen-containing heterocyclic compounds. Kinetic studies on the oxidation reaction of 1-phenylethanol using complex 1 were carried out in the presence and the absence of external triphenylphosphine (PPh3). External addition of PPh3 had a negative influence on the rate of the reaction, which suggested that dissociation of PPh3 occurred during the course of the reaction. Hydrogen was evolved from the oxidation reaction of 1-phenylethanol by using 1 mol% of 1 (88%) and 2 (92%), which demonstrated the possible usage of the catalytic systems in hydrogen generation. Copyright
- Muthaiah, Senthilkumar,Hong, Soon Hyeok
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p. 3045 - 3053
(2013/01/15)
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- CYCLOALKYLAMINE SUBSTITUTED ISOQUINOLINE DERIVATIVES
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The invention relates to 6-substituted isoquinoline derivatives of the Formula (I) useful for the treatment and/or prevention of diseases associated with Rho-kinase and/or Rho-kinase mediated phosphorylation of myosin light chain phosphatase, and compositions containing such compounds.
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Page/Page column 113
(2008/12/06)
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- MACROCYCLIC INHIBITORS OF HEPATITIS C VIRUS
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Inhibitors of HCV replication of formula (I) and the N-oxides, salts, and stereoisomers thereof, wherein X is N, CH and where X bears a double bond it is C; R1 is -OR5, -NH-SO2R6; R2 is hydrogen, and where X is C or CH, R2 may also be C1-6alkyl; R3 is hydrogen, C1-6alkyl, C1-6alkoxyC1-6alkyl, or C3-7cycloalkyl; R4 is isoquinolinyl optionally substituted with one, two or three substituents each independently selected from C1-6alkyl, C1-6alkoxy, hydroxy, halo, polyhalo- C1-6alkyl, polyhaloC1-6alkoxy, amino, mono- or diC1-6alkylamino, mono- or DiC1-6alkylaminocarbonyl, C1-6alkylcarbonyl-amino, aryl, and Het; n is 3, 4, 5, or 6; each dashed line (represented by ) represents an optional double bond; R5 is hydrogen; aryl; Het; C3-7cycloalkyl optionally substituted with C1-6alkyl; or C1-6alkyl optionally substituted with C3-7cycloalkyl, aryl or with Het; R6 is aryl; Het; C3-7cycloalkyl optionally substituted with C1-6alkyl; or C1-6alkyl optionally substituted with C3-7cycloalkyl, aryl or with Het; each aryl is phenyl optionally substituted with one, two or three substituents; and each Het is a 5 or 6 membered saturated, partially unsaturated or completely unsaturated heterocyclic ring containing 1 to 4 heteroatoms each independently selected from nitrogen, oxygen and sulfur, and being optionally substituted with one, two or three substituents; pharmaceutical compositions containing compounds (I) and processes for preparing compounds (I). Bioavailable combinations of the inhibitors of HCV of formula (I) with ritonavir are also provided.
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Page/Page column 74-75
(2008/06/13)
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- PROPANAMINE DERIVATIVES AS SEROTONIN AND NOREPINEPHRINE REUPTAKE INHIBITORS
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There is provided a heretoaryloxy/thio 3-substituted propanamine compound of formula (I) wherein A is selected from -O- and -S-; X is selected from phenyl optionally substituted with up to 5 substituents each independently selected from halo, C1-C4 alkyl and C1-C4 alkoxy, thienyl optionally substituted with up to 3 substituents each independently selected from halo and C1-C4 alkyl, and C2-C8 alkyl, C2-C8 alkenyl, C3-C8 cycloalkyl and C4-C8 cycloalkylalkyl, each of which may be optionally substituted with up to 3 substituents each independently selected from halo, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkyl-S(O)n- where n is 0, 1 or 2, -CF3, -CN and -CONH2; Y is selected from dihydrobenzothienyl, benzothiazolyl, benzoisothiazolyl, quinolyl, isoquinolyl, naphthyridyl, and thienopyridyl, each of which may be optionally substituted with up to 4 or, where possible, up to 5 substituents each independently selected from halo, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkyl-S(O)n- where n is 0, 1 or 2, nitro, acetyl, -CF3, -SCF3 and cyano; Z is selected from H, OR3 or F, wherein R3 is selected from H, C1-C6 alkyl and phenyl C1-C6 alkyl; R1 and R2 are each independently H or C1-C4 alkyl; and pharmaceutically acceptable salts thereof.
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- Improved procedures for large preperation of 6- and 7-oxy-substituted isoquinolines and a convenient work-up protocol for titanium supported reactions
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Improved procedures for large scale preparation of oxy-substituted isoquinolines are reported. Moreover, a simple and convenient protocol for alkaline work-up of titanium containing reaction mixtures is given, which is expected to be of general interest even for reactions on a technical scale.
- Kucznierz, Ralf,Dickhaut, Joachim,Leinert, Herbert,Von Der Saal, Wolfgang
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p. 1617 - 1625
(2007/10/03)
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- Synthesis of isoquinolines from indanones: Total synthesis of illudinine
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Schmidt reaction of 5-methoxy or 7-methoxyindan-1-ones or their derivatives results exclusively in isocarbostyrils which are converted into 6-methoxy or 8-methoxyisoquinolines in good yields.This strategy has been extended to the total synthesis of illudinine methyl ester (1b) starting from methyl 8-methoxy-2,2-dimethyl-7-oxo-1,2,3,5,6,7-hexahydro-s-indacene-4-carboxylate (4).
- Shanker, P. Sathya,Rao, G. S. R. Subba
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p. 1209 - 1213
(2007/10/02)
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- Pharmaceutically active compounds
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The invention relates to a class of tetrahydroisoquinolinylalkanoic acids containing an aryl sulphonamide group which have activity as thromboxane A2 antagonists.
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