- Enantioselective Synthesis of N-Alkylamines through β-Amino C-H Functionalization Promoted by Cooperative Actions of B(C6F5)3and a Chiral Lewis Acid Co-Catalyst
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We disclose a catalytic method for β-C(sp3)-H functionalization of N-alkylamines for the synthesis of enantiomerically enriched β-substituted amines, entities prevalent in pharmaceutical compounds and used to generate different families of chiral catalysts. We demonstrate that a catalyst system comprising of seemingly competitive Lewis acids, B(C6F5)3, and a chiral Mg- or Sc-based complex, promotes the highly enantioselective union of N-alkylamines and α,β-unsaturated compounds. An array of δ-amino carbonyl compounds was synthesized under redox-neutral conditions by enantioselective reaction of a N-alkylamine-derived enamine and an electrophile activated by the chiral Lewis acid co-catalyst. The utility of the approach is highlighted by late-stage β-C-H functionalization of bioactive amines. Investigations in regard to the mechanistic nuances of the catalytic processes are described.
- Chang, Yejin,Cao, Min,Chan, Jessica Z.,Zhao, Cunyuan,Wang, Yuankai,Yang, Rose,Wasa, Masayuki
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p. 2441 - 2455
(2021/02/16)
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- N-(PYRIDIN-2-YLSULFONYL)CYCLOPROPANECARBOXAMIDE DERIVATIVES AND THEIR USE IN THE TREATMENT OF A CFTR MEDIATED DISEASE
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The invention relates to heterocyclic compounds of the formula (I), in which all of the variables are as defined in the specification; capable of modulating the activity of CFTR. The invention further provides a method for manufacturing compounds of the invention, and its therapeutic uses. The invention further provides methods to their preparation, to their medical use, in particular to their use in the treatment and management of diseases or disorders including Cystic fibrosis and related disorders.
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- Iron-catalyzed oxidative C(3)-H functionalization of amines
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Fe-catalyzed direct dehydrogenative C(3)-functionalization of tertiary arylamines was developed via activation of the sp3 C(3)-H bond. The reaction is applicable to both cyclic and acyclic amines. The key process is the catalytic desaturative enamine formation from tertiary amines and position-selective C-C bond formation (addition to nitro olefins) at the β-carbon. Products can be converted to versatile and unique nitrogen-containing molecules.
- Takasu, Noriaki,Oisaki, Kounosuke,Kanai, Motomu
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supporting information
p. 1918 - 1921
(2013/06/04)
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- Organosulfur Chemistry. II. Use of Dimethyl Sulfoxide; a Facile Synthesis of Cyclic Sulfides
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A versatile and short-reaction-time synthesis of twelve four-, five- and six-membered thiacycloalkanes (IIa-l)from the appropriate α,ω-dibromoalkanes (Ia-l)has been developed.Technical-grade dimethyl sulfoxide was proved to be by far the best for this cyclization.The pronounced effect for ring formation was recognized to be in order of five-membered ring (thiolanes) > six-membered ring (thianes) > four-membered ring (thietanes).Startling were 2-methylthiolane (IIf) and 2,5-dimethylthiolane (IIg; cis/trans mixture), both obtained in high yields although α-methyl - and α,α'-dimethyl substitution in general showing a remarkable retardation for cyclization.On the other hand, in both 3,3-dimethylthietane (IId) and 4,4-dimethylthiane (IIl) cyclization was much more efficient than other counterparts in each series, which is referred to as the gem-dimethyl effect.Keywords: thiacycloalkane; thietane; thiolane; thiane; dimethyl sulfoxide; cyclization: α,ω-dibromoalkane; sodium sulfide nonahydrate; refractive index
- Nagasawa, Kazuo,Yoneta, Akemi
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p. 5048 - 5052
(2007/10/02)
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- Alkylsubstituted Cyclopentanones via Hydrocarbonylating Cyclization of 1,4-Pentadiene Systems Mediated by Metal Carbonyls
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3,3-Dialkyl-1,4-pentadienes 8 under the influence of metal carbonyls can be converted to unsymmetrically substituted cyclopentanones 9 by hydrocarbonylating cyclization with carbon monoxide and hydrogen or water.Starting from 1,1-divinylcycloalkanes of type 8 this method can also be used for the synthesis of spirocyclopentanones.The yields of cyclic ketones with the here used dienes are markedly better than with the unsubstituted 1,4-pentadiene itself.
- Eilbracht, Peter,Acker, Michael,Totzauer, Walter
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p. 238 - 242
(2007/10/02)
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- Intramolecular and Intermolecular Reactions of Alkenylsilyl Radicals
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The radicals formed during photolysis of di-t-butyl peroxide and a number of alkenyldimethylsilanes have been examined by e.s.r. spectroscopy.Only carbon-centred radicals were observed.These were either secondary alkyl radicals formed by the addition of the initially formed silyl radical to a double bond and/or allyl radicals formed by hydrogen-atom abstraction from the alkenyl group.In most cases addition to the double bond was an intermolecular process.However, pent-4-enylsilyl radicals undergo intramolecular addition with endo-cyclization to form the six-membered ring being strongly favoured over exo-cyclization to form the five-membered ring.This preference was confirmed by product studies on 3,3-dimethylpent-4-enyldimethylsilane.The factors that control homolytic exo:endo cyclization rates for species in which the radical centre is located on a second row element are adumbrated.
- Chatgilialoglu, Chryssostomos,Woynar, Helmut,Ingold, Keith U.
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p. 555 - 562
(2007/10/02)
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