- Diastereoselective Rhodium-Catalyzed Hydrogenation of 2-Oxindoles and 3,4-Dihydroquinolones
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The benzene ring of indolin-2-ones (2-oxindoles) and 3,4-dihydroquinol-2-ones was converted to a saturated cyclohexane ring by hydrogenation in the presence of the rhodium complex Cy(CAAC)Rh(cod)Cl. The stereoselectivity of the process was found to be high with respect to both external substituent R1 within the saturated part of the heterocyclic ring and substituent X on the benzene ring. Twenty-one hexahydroindolin-2(3H)-ones (70-99% yield, dr = 83/17 to >99/1) and twelve octahydro-2(1H)-quinolinones (87-96% yield, dr = 64/36 to >99/1) were obtained with the major diastereoisomer exhibiting the hydrogen atoms in an all-cis arrangement. The high tolerance toward functional groups and the compatibility with existing stereogenic centers are key features of the hydrogenation protocol presented here.
- Schiwek, Christian H.,Jandl, Christian,Bach, Thorsten
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supporting information
p. 9468 - 9472
(2020/11/30)
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- Catalytic Kinetic Resolution of Disubstituted Piperidines by Enantioselective Acylation: Synthetic Utility and Mechanistic Insights
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The catalytic kinetic resolution of cyclic amines with achiral N-heterocyclic carbenes and chiral hydroxamic acids has emerged as a promising method to obtain enantio-enriched amines with high selectivity factors. In this report, we describe the catalytic kinetic resolution of disubstituted piperdines with practical selectivity factors (s, up to 52) in which we uncovered an unexpected and pronounced conformational effect resulting in disparate reactivity and selectivity between the cis- and trans-substituted piperidine isomers. Detailed experimental and computational studies of the kinetic resolution of various disubstituted piperidines revealed a strong preference for the acylation of conformers in which the α-substituent occupies the axial position. This work provides further experimental and computational support for the concerted 7-member transition state model for acyl transfer reagents and expands the scope and functional group tolerance of the secondary amine kinetic resolution.
- Wanner, Benedikt,Kreituss, Imants,Gutierrez, Osvaldo,Kozlowski, Marisa C.,Bode, Jeffrey W.
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p. 11491 - 11497
(2015/09/21)
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- Highly Selective Hydrogenation of Aromatic Ketones and Phenols Enabled by Cyclic (Amino)(alkyl)carbene Rhodium Complexes
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Air-stable Rh complexes ligated by strongly σ-donating cyclic (amino)(alkyl)carbenes (CAACs) show unique catalytic activity for the selective hydrogenation of aromatic ketones and phenols by reducing the aryl groups. The use of CAAC ligands is essential for achieving high selectivity and conversion. This method is characterized by its good compatibility with unsaturated ketones, esters, carboxylic acids, amides, and amino acids and is scalable without detriment to its efficiency.
- Wei, Yu,Rao, Bin,Cong, Xuefeng,Zeng, Xiaoming
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supporting information
p. 9250 - 9253
(2015/08/11)
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- Bicyclic amidine inhibitors of nitric oxide synthase: Discovery of perhydro-iminopyrindine and perhydro-iminoquinoline as potent, orally active inhibitors of inducible nitric oxide synthase
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Syntheses and nitric oxide synthase inhibitory activity of cyclic amidines containing 5,6- 6,6- and 7,6-fused systems are described. X-ray structure determination facilitated the assignment of the stereochemistry of the most active compounds perhydro-2-im
- Guthikonda, Ravindra N.,Shah, Shrenik K.,Pacholok, Stephen G.,Humes, John L.,Mumford, Richard A.,Grant, Stephan K.,Chabin, Renee M.,Green, Barbara G.,Tsou, Nancy,Ball, Richard,Fletcher, Daniel S.,Luell, Silvi,Euan MacIntyre,MacCoss, Malcolm
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p. 1997 - 2001
(2007/10/03)
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- Cyclic amidine analogs as inhibitors of nitric oxide synthase
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Disclosed herein are compounds of Formula I STR1 and pharmaceutically acceptable salts thereof which have been found useful in the treatment of nitric oxide synthase mediated diseases and disorders, including neurodegenerative disorders, disorders of gastrointestinal motility and inflammation. These disease and disorders include hypotension, septic shock, toxic shock syndrom, hemodialysis, IL-2 therapy such as in cancer patients, cachexia, immunosuppression such as in transplant therapy, autoimmune and/or inflammatory indications including sunburn or psoriasis and respiratory conditions such as bronchitis, asthma, and acure respiratory distress (ARDS), myocarditis, heart failure, atherosclerosis, arthritis, rheumatoid arthritis, chronic or inflammatory bowel disease, ulcerative colitis, Crohn's disease, systemic lupus erythematosis (SLE), ocular conditions such as ocular hypertension and uveitis, type 1 diabetes, insulin-dependent diabetes mellitus and cystic fibrosis. Compounds of Formula I are also usful in the treatment of hypoxia, hyperbaric oxygen convulsions and toxicity, dementia, Sydenham's chorea, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, mulitple sclerosis, Korsakoff's disease, imbecility related to cerebral vessel disorder, ischemic brain edema, sleeping disorders, schizophrenia, depression, PMS, anxiety, drug addiction, pain, migraine, immune complex disease, as immunosupressive agents and for preventing or reversing tolerance to opiates and diazepines.
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- Ruthenium-Catalyzed Hydration of Nitriles and Transformation of δ-Keto Nitriles to Ene-Lactams
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Hydration of nitriles and transformation of δ-keto nitriles to ene-lactams can be performed efficiently by using RuH2(PPh3)4 catalyst under mild conditions.The effectiveness of the reaction is illustrated by the short-step synthesis of (-)-pumiliotoxin C.
- Murahashi, Shun-Ichi,Sasao, Shigehiro,Saito, Eiichiro,Naota, Takeshi
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p. 2521 - 2523
(2007/10/02)
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- Derivatives of bicyclic aminoacids agents containing these compounds and their use
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Disclosed are cis, exo- and trans-compounds of the formula I STR1 in which n denotes 0, 1 or 2, R1 denotes hydrogen, (C1 -C6)-alkyl which can optionally be substituted by amino, (C1 -C4)-acyl- or bezoylamino, (C2 -C6)-alkenyl, (C5 -C9)-cycloalkyl, (C5 -C9)-cycloalkenyl, (C5 -C7)-cycloalkyl-(C1 -C4)-alkyl, aryl or partially hydrogenated aryl, which can, in each case, be substituted by (C1 -C2)-alkyl, (C1 -C2)-alkoxy or halogen, aryl-(C1 -C4)-alkyl, /which can be substituted as defined previously in the aryl radical/, a monocyclic or bicyclic sulfur or nitrogen and/or nitrogen heterocyclic radical, or a side chain of naturally occurring aminoacid, R2 denotes hydrogen, (C1 -C6)-alkyl, (C2 -C6)-alkenyl or aryl-(C1 -C4)-alkyl, Y denotes hydrogen or hydroxyl, Z denotes hydrogen or Y and Z together denote oxygen, X denotes (C1 -C6)-alkyl, (C2 -C6)-alkenyl, (C6 -C9)-cycloalkyl or aryl which can be mono-, di- or tri- substituted by (C1 -C4)-alkyl, (C1 -C4)-alkoxy, hydroxyl, halogen, nitro, amino, (C1 -C4)-alkylamino, di-(C1 -C4 -alkylamino or methylenedioxy, or indol-3-yl, or physiologically acceptable salts thereof, a process of the preparation thereof, agents containing them, their use as a medicine and intermediates for the preparation thereof.
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