- Aza-Matteson Reactions via Controlled Mono-and Double-Methylene Insertions into Nitrogen-Boron Bonds
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Boron-homologation reactions represent an efficient and programmable approach to prepare alkylboronates, which are valuable and versatile synthetic intermediates. The typical boron-homologation reaction, also known as the Matteson reaction, involves formal carbenoid insertions into C-B bonds. Here we report the development of aza-Matteson reactions via carbenoid insertions into the N-B bonds of aminoboranes. By changing the leaving groups of the carbenoids and altering Lewis acid activators, selective mono- and double-methylene insertions can be realized to access various α- and β-boron-substituted tertiary amines, respectively, from common secondary amines. The derivatization of complex amine-containing bioactive molecules, diverse functionalization of the boronate products, and sequential insertions of different carbenoids have also been achieved.
- Xie, Qiqiang,Dong, Guangbin
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p. 14422 - 14427
(2021/09/29)
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- Direct hydroxyethylation of amines by carbohydrates: Via ruthenium catalysis
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An efficient and halogen-free catalytic methodology for the synthesis of β-amino alcohols from aromatic amines and biomass-derived carbohydrates is demonstrated for the first time. The activation of C5/C6 sugars by a ruthenium catalyst selectively generates the C2 alkylating reagent glycolaldehyde. The transformation involves metal-catalyzed hydrogen borrowing for the reduction of the imine intermediate. A series of arylamines bearing various substituents were successfully transformed into the desired products in good to excellent yields.
- Jia, Le,Makha, Mohamed,Du, Chen-Xia,Quan, Zheng-Jun,Wang, Xi-Cun,Li, Yuehui
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supporting information
p. 3127 - 3132
(2019/06/18)
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- Facile N-arylation of amines and sulfonamides and O-arylation of phenols and arenecarboxylic acids
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An efficient, transition-metal-free procedure for the N-arylation of amines, sulfonamides, and carbamates and O-arylation of phenols and carboxylic acids has been achieved by allowing these substrates to react with a variety of o-silylaryl inflates in the presence of CsF. Good to excellent yields of arylated products are obtained under very mild reaction conditions. This chemistry readily tolerates a variety of functional groups.
- Liu, Zhijian,Larock, Richard C.
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p. 3198 - 3209
(2007/10/03)
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- Bioisosteric replacement in the design and synthesis of ligands for nicotinic acetylcholine receptors
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A series of ethers containing pyrrolidine and/or pyridine bioisosteres was synthesized and evaluated as nicotinic ligands. The dimethylaminoethoxypyridines 6 and 7 inhibited the specific binding of (-)-[3H]Nicotine with Ki values of 300 nM and 450 nM, respectively. Compounds 8 and 9 were found to have Ki values of 3390 nM and 360 nM. These results suggest that dialkylamino and appropriately substituted benzene rings (NO2, 8; OH, 9) are bioisosteric replacements for pyrrolidine and pyridine, respectively. Birkhaeuser Boston 2006.
- Sun, Weilin,Blanton, Michael P.,Gabriel, Jerome L.,Canney, Daniel J.
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p. 241 - 259
(2007/10/03)
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- Method of treating filariae
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The present invention relates to a novel method for treating a mammal suffering from filariae.
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- Synthesis of novel GABA uptake inhibitors. 4. Bioisosteric transformation and successive optimization of known GABA uptake inhibitors leading to a series of potent anticonvulsant drug candidates
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By bioisosteric transformations and successive optimization of known GABA uptake inhibitors, several series of novel GABA uptake inhibitors have been prepared by different synthetic approaches. These compounds are derivatives of nipecotic acid and guvacine, substituted at the nitrogen of these amino acids by various lipophilic moieties such as diarylaminoalkoxyalkyl or diarylalkoxyalkyl. The in vitro values for inhibition of [3H]GABA uptake in rat synaptosomes was determined for each compound, and it was found that the most potent compound from this series, (R)-1-(2-(3,3-diphenyl-1-propyloxy)ethyl)-3-piperidinecarboxylic acid hydrochloride (29), is so far the most potent parent compound inhibiting GABA uptake into synaptosomes. Structure-activity results confirm our earlier observations, that an electronegative center in the chain connecting the amino acid and diaryl moiety is very critical in order to obtain high in vitro potency. Several of the novel compounds were also evaluated for their ability in vivo to inhibit clonic seizures induced by a 15 mg/kg (ip) dose of methyl 6,7-dimethoxy-4-ethyl-β-carboline-3-carboxylate (DMCM). Some of the compounds tested show a high in vivo potency comparable with that of the recently launched anticonvulsant product 6 ((R)-1-(4,4-bis(3-methyl-2- thienyl)-3-butenyl)-3-piperidinecarboxylic acid).
- Andersen, Knud Erik,S?rensen, Jan L.,Huusfeldt, Per O.,Knutsen, Lars J. S.,Lau, Jesper,Lundt, Behrend F.,Petersen, Hans,Suzdak, Peter D.,Swedberg, Michael D. B.
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p. 4281 - 4291
(2007/10/03)
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- Heterocyclic carboxylic acids
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Novel N-substituted azaheterocyclic carboxylic acids and esters thereof in which a substituted alkyl chain forms part of the N-substituent, the compounds thus having the general formula I STR1 wherein Y is STR2 wherein R1 and R2 independently are C3-8 cycloalkyl phenyl or thienyl all of which may be optionally substituted with halogen, trifluoromethyl, C1-16 alkyl or C1-6 alkoxy; s is 1, 2 or 3; x is --CH2 --, --O-- or STR3 -wherein R3 is hydrogen or C1-6 -alkyl; r is 2, 3 or 4; R4 and R5 each represents hydrogen or may together represent a bond and R6 is OH or C1-8 -alkoxy; and pharmaceutically acceptable acid addition salts are potent inhibitors of GABA uptake from the synaptic cleft.
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- Omega-quaternary ammonium alkyl esters and thioesters of acidic nonsteroidal antiinflammatory drugs
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Quaternary ammonium alkyl esters and thioesters of acidic nonsteroidal anti-inflammatory drugs (NSAIDs) are disclosed. These esters and thioesters display the anti--inflammatory profile of the parent NSAIDs with greatly reduced gastrointestinal irritancy, providing a more favorable separation of therapeutic activity and toxicological side effects than the parent NSAIDs.
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- The Catalytic Effect of Copper Ions in the Phenylation Reaction of David and Thieffry
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Several types of bifunctional molecules are smoothly phenylated by triphenylbismuth diacetate in a reaction which has an induction period, a curious solvent dependence, and the need for illumination; however, the addition of a small amount of Cu(OAc)2 removes all these limitations and accelerates greatly the reaction.
- Barton, Derek H. R.,Finet, Jean-Pierre,Pichon, Clotilde
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