- Defunctionalization of sp3 C–Heteroatom and sp3 C–C Bonds Enabled by Photoexcited Triplet Ketone Catalysts
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A general strategy for enabling a light-induced defunctionalization of sp3 C–heteroatom and sp3 C–C bonds with triplet ketone catalysts and bipyridine additives is disclosed. This protocol is characterized by its broad scope without recourse to transition metal catalysts or stoichiometric exogeneous reductants, thus offering a complementary technique for activating σ sp3 C–C(heteroatom) bonds. Preliminary mechanistic studies suggest that the presence of 2,2′-bipyridines improves the lifetime of ketyl radical intermediates.
- An, Juzeng,Gu, Yiting,Martin, Ruben,Wakeling, Matthew,Yin, Hongfei
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p. 1031 - 1036
(2022/01/19)
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- Enantio- and Site-Selective α-Fluorination of N-Acyl 3,5-Dimethylpyrazoles Catalyzed by Chiral π–CuII Complexes
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Catalytic enantioselective α-fluorination reactions of carbonyl compounds are among the most powerful and efficient synthetic methods for constructing optically active α-fluorinated carbonyl compounds. Nevertheless, α-fluorination of α-nonbranched carboxylic acid derivatives is still a big challenge because of relatively high pKa values of their α-hydrogen atoms and difficulty of subsequent synthetic transformation without epimerization. Herein we show that chiral copper(II) complexes of 3-(2-naphthyl)-l-alanine-derived amides are highly effective catalysts for the enantio- and site-selective α-fluorination of N-(α-arylacetyl) and N-(α-alkylacetyl) 3,5-dimethylpyrazoles. The substrate scope of the transformation is very broad (25 examples including a quaternary α-fluorinated α-amino acid derivative). α-Fluorinated products were converted into the corresponding esters, secondary amides, tertiary amides, ketones, and alcohols with almost no epimerization in high yield.
- Ishihara, Kazuaki,Nishimura, Kazuki,Yamakawa, Katsuya
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supporting information
p. 17641 - 17647
(2020/08/14)
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- Catalytic Hydroetherification of Unactivated Alkenes Enabled by Proton-Coupled Electron Transfer
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We report a catalytic, light-driven method for the intramolecular hydroetherification of unactivated alkenols to furnish cyclic ether products. These reactions occur under visible-light irradiation in the presence of an IrIII-based photoredox catalyst, a Br?nsted base catalyst, and a hydrogen-atom transfer (HAT) co-catalyst. Reactive alkoxy radicals are proposed as key intermediates, generated by direct homolytic activation of alcohol O?H bonds through a proton-coupled electron-transfer mechanism. This method exhibits a broad substrate scope and high functional-group tolerance, and it accommodates a diverse range of alkene substitution patterns. Results demonstrating the extension of this catalytic system to carboetherification reactions are also presented.
- Knowles, Robert R.,Metrano, Anthony J.,Tsuchiya, Yuto,Tsui, Elaine
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supporting information
p. 11845 - 11849
(2020/05/22)
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- Radical C?H-Amination of Heteroarenes using Dual Initiation by Visible Light and Iodine
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A novel light-induced C?H amination of heteroarenes can be accomplished with preformed iodine(III) reagents as the combined oxidant and nitrogen source. The reaction requires the use of a small amount of molecular iodine, which under photochemical activation generates in situ an iodine(I) reagent as the initiator of the radical amination reaction. A total of 32 examples exemplify the broad scope of the transformation. (Figure presented.).
- Lucchetti, Nicola,Tkacheva, Anastasia,Fantasia, Serena,Mu?iz, Kilian
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supporting information
p. 3889 - 3893
(2018/09/21)
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- SUBSTITUTED INDOLE MCL-1 INHIBITORS
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The present application, among other things, provides compounds that are capable of inhibiting the activity of anti-apoptotic Bcl-2 family proteins, for example, myeloid cell leukemia-1 (Mcl-1) protein. The present invention also provides pharmaceutical compositions as well as methods for using provided compounds for treatment of diseases and conditions (e.g., cancer) characterized by the over-expression or dysregulation of Mcl-1 protein. In some embodiments, a provided compound has the structure of formula I. In some embodiments, a provided compound has the structure of formula II.
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Paragraph 00352
(2015/03/16)
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- Enantioselective linchpin catalysis by SOMO catalysis: An approach to the asymmetric a-chlorination of aldehydes and terminal epoxide formation
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Time for SOme MOre: For the first time SOMO (singly occupied molecular orbital) activation has been exploited to allow a new approach to the α-chlorination of aldehydes. This transformation can be readily implemented as part of a linchpin catalysis approach to the enantioselective production of terminal epoxides.
- Amatore, Muriel,Beeson, Teresa D.,Brown, Sean P.,MacMillan, David W. C.
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supporting information; experimental part
p. 5121 - 5124
(2009/12/07)
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- Preparation of β2-homotryptophan derivatives for β-peptide synthesis
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In view of the prominent role of the 1H-indol-3-yl side chain of tryptophan in peptides and proteins, it is important to have the appropriately protected homologs H-β2-HTrp-OH and H-β3-HTrp-OH (Fig.) available for incorporation in β-
- Micuch, Peter,Seebach, Dieter
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p. 1567 - 1577
(2007/10/03)
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- Cyclic carbamates and isoxazolidines as IIb/IIIa antagonists
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The present invention relates generally to cyclic carbamates and isoxazolidines or Formula (I) or their pharmaceutically acceptable salts thereof, which are useful as antagonists of the platelet glycoprotein IIb/IIIa fibrinogen receptor complex, to pharma
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