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1.
Dr. Andranik Petrosyan Luisa Zach Dr. Tobias Taeufer T. S. Mayer Dr. Jabor Rabeah Dr. Jola Pospech 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(57):e202201761
Herein we report a photo-mediated formal addition of carboxylic acids to activated alkenes catalyzed by a pyrimidopteridine photoredox catalyst. The decarboxylation of aliphatic carboxylic acids upon single-electron oxidation is countered in the presence of electron-rich alkenes and a hydroacetoxylation is observed. Mechanistic proposals have been made based on CV measurements, competitive Stern-Volmer quenching and EPR experiments. Evidence that tetra-N-substituted pyrimidopteridines function as dual photoredox and hydrogen atom transfer catalyst was supported by spectroscopic means. 相似文献
2.
Prof. Yasuharu Yoshimi 《Chemical record (New York, N.Y.)》2024,24(3):e202300326
Using our recent relevant results, this account shows the featured reactivities of two-molecule photoredox systems compared to one-molecule photoredox systems. The low efficiency of electron transfer processes, such as photoinduced and back-electron transfer, in the two-molecule photoredox system, furnishes unique products through different pathways. The facile replacement of photoredox catalysts with appropriate oxidation/reduction potentials in this system provides valuable insights into photoredox reactions. 相似文献
3.
Dual Catalytic Decarboxylative Allylations of α‐Amino Acids and Their Divergent Mechanisms
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Simon B. Lang Kathryn M. O'Nele Dr. Justin T. Douglas Prof. Dr. Jon A. Tunge 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(51):18589-18593
The room temperature radical decarboxylative allylation of N‐protected α‐amino acids and esters has been accomplished via a combination of palladium and photoredox catalysis to provide homoallylic amines. Mechanistic investigations revealed that the stability of the α‐amino radical, which is formed by decarboxylation, dictates the predominant reaction pathway between competing mechanisms. 相似文献
4.
《中国化学》2017,35(10):1491-1500
In recent years, a methodology merging photoredox catalysis with organocatalysis termed “photoredox organocatalysis” has emerged to allow the direct, selective and efficient functionalization of the α /β ‐C of carbonyl compounds under mild reaction condition. In this review, photophysics background of photoredox catalysis is introduced, followed by a report on recent advances in direct α ‐ and β ‐functionalization of carbonyls with photoredox organocatalysis methodology. With this different reaction modes, valuable synthetic targets including different α /β ‐functionalized carbonyls are accessible. 相似文献
5.
Rehanguli Ruzi Junyang Ma Prof. Dr. Xiang-Ai Yuan Wenliang Wang Shanshan Wang Dr. Muliang Zhang Dr. Jie Dai Prof. Dr. Jin Xie Prof. Dr. Chengjian Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(55):12724-12729
An unprecedented deoxygenative arylation of aromatic carboxylic acids has been achieved, allowing the construction of an enhanced library of unsymmetrical diaryl ketones. The synergistic photoredox catalysis and phosphoranyl radical chemistry allows for precise cleavage of a stronger C−O bond and formation of a weaker C−C bond by 1,5-aryl migration under mild reaction conditions. This new protocol is independent of substrate redox-potential, electronic, and substituent effects. It affords a general and promising access to 60 examples of synthetically versatile o-amino and o-hydroxy diaryl ketones under redox-neutral conditions. Furthermore, it also brings one concise route to the total synthesis of quinolone alkaloid, (±)-yaequinolone A2, and a viridicatin derivative in satisfying yields. 相似文献
6.
α‐Arylation/Heteroarylation of Chiral α‐Aminomethyltrifluoroborates by Synergistic Iridium Photoredox/Nickel Cross‐Coupling Catalysis
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Dr. Mirna El Khatib Dr. Ricardo Augusto Massarico Serafim Prof. Gary A. Molander 《Angewandte Chemie (International ed. in English)》2016,55(1):254-258
Direct access to complex, enantiopure benzylamine architectures using a synergistic iridium photoredox/nickel cross‐coupling dual catalysis strategy has been developed. New C(sp3)? C(sp2) bonds are forged starting from abundant and inexpensive natural amino acids. 相似文献
7.
Shorouk O. Badir Audrey Dumoulin Jennifer K. Matsui Prof. Gary A. Molander 《Angewandte Chemie (International ed. in English)》2018,57(22):6610-6613
The incorporation of C‐glycosides in drug design has become a routine practice for medicinal chemists. These naturally occurring building blocks exhibit attractive pharmaceutical profiles, and have become an important target of synthetic efforts in recent decades. 1 Described herein is a practical, scalable, and versatile route for the synthesis of non‐anomeric and unexploited C‐acyl glycosides through a Ni/photoredox dual catalytic system. By utilizing an organic photocatalyst, a range of glycosyl‐based radicals are generated and efficiently coupled with highly functionalized carboxylic acids at room temperature. Distinctive features of this transformation include its mild conditions, impressive compatibility with a wide array of functional groups, and most significantly, preservation of the anomeric carbon: a handle for further, late‐stage derivatization. 相似文献
8.
One‐Pot Tandem Photoredox and Cross‐Coupling Catalysis with a Single Palladium Carbodicarbene Complex
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Yu‐Cheng Hsu Vincent C.‐C. Wang Ka‐Chun Au‐Yeung Chung‐Yu Tsai Chun‐Chi Chang Bo‐Chao Lin Prof. Yi‐Tsu Chan Prof. Chao‐Ping Hsu Prof. Glenn P. A. Yap Prof. Titel Jurca Prof. Tiow‐Gan Ong 《Angewandte Chemie (International ed. in English)》2018,57(17):4622-4626
The combination of conventional transition‐metal‐catalyzed coupling (2 e? process) and photoredox catalysis (1 e? process) has emerged as a powerful approach to catalyze difficult cross‐coupling reactions under mild reaction conditions. Reported is a palladium carbodicarbene (CDC) complex that mediates both a Suzuki–Miyaura coupling and photoredox catalysis for C?N bond formation upon visible‐light irradiation. These two catalytic pathways can be combined to promote both conventional transition‐metal‐catalyzed coupling and photoredox catalysis to mediate C?H arylation under ambient conditions with a single catalyst in an efficient one‐pot process. 相似文献
9.
In this paper, we report a mild and practical method for precise deuteration of aliphatic carboxylic acids by synergistic photoredox and HAT catalysis. The reaction delivers excellent D-incorporation (up to 99%) at predicted sites even in substrates bearing reactive C–H bonds or versatile functional groups. The use of a recirculation reactor with a peristaltic pump supports a scalable preparative ability (up to 50 mmol) under very mild reaction conditions. The practical and precise deuteration of readily available complex carboxylic acids makes this protocol promising for the preparation of deuterium-labelled compounds.A scalable, practical and general method for precise deuteration of aliphatic carboxylic acids via synergistic photoredox and HAT catalysis has been developed. The use of recirculation reactor achieved the preparative scale deuteration. 相似文献
10.
Combining Photoredox‐Catalyzed Trifluoromethylation and Oxidation with DMSO: Facile Synthesis of α‐Trifluoromethylated Ketones from Aromatic Alkenes
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Ren Tomita Dr. Yusuke Yasu Dr. Takashi Koike Prof. Dr. Munetaka Akita 《Angewandte Chemie (International ed. in English)》2014,53(28):7144-7148
Trifluoromethylated ketones are useful building blocks for organic compounds with a trifluoromethyl group. A new and facile synthesis of ketones with a trifluoromethyl substituent in the α‐position proceeds through a one‐pot photoredox‐catalyzed trifluoromethylation–oxidation sequence of aromatic alkenes. Dimethyl sulfoxide (DMSO) serves as a key and mild oxidant under these photocatalytic conditions. Furthermore, an iridium photocatalyst, fac[Ir(ppy)3] (ppy=2‐phenylpyridine), turned out to be crucial for the present photoredox process. 相似文献
11.
12.
Daniel Lin Juan Pablo de los Rios Prof. Dr. G. K. Surya Prakash 《Angewandte Chemie (International ed. in English)》2023,62(30):e202304294
N-(difluoromethyl)amino (−NCF2H) compounds are of great interest given their unique and underexplored physiochemical properties. The lack of structural diversity in NCF2H compounds is likely due in part to the shortage of protocols for efficient installation. Presented herein is a new shelf-stable pyridinium reagent that enables the direct installation of the N-(difluoromethyl)sulfonamide moiety [N(Ts)CF2H)] onto (hetero)arenes and alkenes for the diversification of aryl and alkyl NCF2H compounds. The described protocol utilizes blue light photoredox catalysis and displays broad functional group tolerance with excellent chemoselectivity. Additional transformations and applicability towards a photoredox continuous flow protocol are also demonstrated. 相似文献
13.
Guillaume Ernouf Egor Chirkin Lydia Rhyman Ponnadurai Ramasami Jean‐Christophe Cintrat 《Angewandte Chemie (International ed. in English)》2020,59(7):2618-2622
A new photoredox‐catalyzed decarboxylative radical addition approach to functionalized cyclobutanes is described. The reaction involves an unprecedented formal Giese‐type addition of C(sp3)‐centered radicals to highly strained bicyclo[1.1.0]butanes. The mild photoredox conditions, which make use of a readily available and bench stable phenyl sulfonyl bicyclo[1.1.0]butane, proved to be amenable to a diverse range of α‐amino and α‐oxy carboxylic acids, providing a concise route to 1,3‐disubstituted cyclobutanes. Furthermore, kinetic studies and DFT calculations unveiled mechanistic details on bicyclo[1.1.0]butane reactivity relative to the corresponding olefin system. 相似文献
14.
Vincent Besse Loïc Le Pluart Wayne D. Cook Thi‐Nhàn Pham Pierre‐Jean Madec 《Journal of polymer science. Part A, Polymer chemistry》2013,51(23):5046-5055
Phosphonic acids are known to be useful monomers in dental restorative materials because of their good potential to provide enhanced adhesion to hydroxyapatite and their high hydrolytic stability. In this study, the photopolymerization of phosphonic acid‐based monomer via the camphorquinone (CQ)/ethyl‐4‐(dimethylaminobenzoate) (EDAB) photoredox system is compared with a ternary system composed of iodonium hexafluorophosphate and CQ/EDAB. Photocalorimetry shows that the ternary system does not provide a significant acceleration of the polymerization with either acrylamide or methacrylate phosphonic acids. The complexation of the iodonium by the phosphonic moiety of the acidic monomers leads to a lowered iodonium reactivity and reduced polarizability of the medium and as a consequence limits the rate enhancement effect normally observed by phosphonic acids on the polymerization rate. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 5046–5055 相似文献
15.
Cecilia Bottecchia Dr. Timothy Noël 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(1):26-42
In the last decade, visible-light photoredox catalysis has emerged as a powerful strategy to enable novel transformations in organic synthesis. Owing to mild reaction conditions (i.e., room temperature, use of visible light) and high functional-group tolerance, photoredox catalysis could represent an ideal strategy for chemoselective biomolecule modification. Indeed, a recent trend in photoredox catalysis is its application to the development of novel methodologies for amino acid modification. Herein, an up-to-date overview of photocatalytic methodologies for the modification of single amino acids, peptides, and proteins is provided. The advantages offered by photoredox catalysis and its suitability in the development of novel biocompatible methodologies are described. In addition, a brief consideration of the current limitations of photocatalytic approaches, as well as future challenges to be addressed, are discussed. 相似文献
16.
Merger of Visible Light Induced Oxidation and Enantioselective Alkylation with a Chiral Iridium Catalyst
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Chuanyong Wang Yu Zheng Haohua Huo Philipp Röse Dr. Lilu Zhang Dr. Klaus Harms Prof. Dr. Gerhard Hilt Prof. Dr. Eric Meggers 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(20):7355-7359
A single chiral octahedral iridium(III) complex is used for visible light activated asymmetric photoredox catalysis. In the presence of a conventional household lamp and under an atmosphere of air, the oxidative coupling of 2‐acyl‐1‐phenylimidazoles with N,N‐diaryl‐N‐(trimethylsilyl)methylamines provides aminoalkylated products in 61–93 % yields with high enantiomeric excess (90–98 % ee). Notably, the iridium center simultaneously serves three distinct functions: as the exclusive source of chirality, as the catalytically active Lewis acid, and as a central part of the photoredox sensitizer. This conceptionally simple reaction Scheme may provide new avenues for the green synthesis of non‐racemic chiral molecules. 相似文献
17.
Ze-Kun Yang Ning-Xin Xu Dr. Chao Wang Prof. Dr. Masanobu Uchiyama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(21):5433-5439
Herein we report a versatile Mizoroki–Heck-type photoinduced C(sp3)−N bond cleavage reaction. Under visible-light irradiation (455 nm, blue LEDs) at room temperature, alkyl Katritzky salts react smoothly with alkenes in a 1:1 molar ratio in the presence of 1.0 mol % of commercially available photoredox catalyst without the need for any base, affording the corresponding alkyl-substituted alkenes in good yields with broad functional-group compatibility. Notably, the E/Z-selectivity of the alkene products can be controlled by an appropriate choice of photoredox catalyst. 相似文献
18.
Anne Roly Obah Kosso Nicolas Sellet Alexandre Baralle Morgan Cormier Jean-Philippe Goddard 《Chemical science》2021,12(20):6964
Direct metal-free near infra-red photoredox catalysis is applied to organic oxidation, photosensitization and reduction, involving cyanines as photocatalysts. This photocatalyst is competitive with conventional reactions catalyzed under visible light. Kinetic and quenching experiments are also reported. Interestingly, these systems are compatible with water media, opening perspective for various applications.Direct metal-free near infra-red photoredox catalysis is applied to oxidation, reduction and photosensitization, involving cyanines as photocatalysts. Mechanistic insights through kinetic and quenching experiments are also reported. 相似文献
19.
CH Functionalization of Phenols Using Combined Ruthenium and Photoredox Catalysis: In Situ Generation of the Oxidant
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M. Sc. David C. Fabry B. Sc. Meria A. Ronge Dipl.‐Chem. Jochen Zoller Prof. Dr. Magnus Rueping 《Angewandte Chemie (International ed. in English)》2015,54(9):2801-2805
A combination of ruthenium and photoredox catalysis allowed the ortho olefination of phenols. Using visible light, the direct C? H functionalization of o‐(2‐pyridyl)phenols occurred, and diverse phenol ethers were obtained in good yields. The regeneration of the ruthenium catalyst was accomplished by a photoredox‐catalyzed oxidative process. 相似文献
20.
Gold‐Catalyzed Highly Selective Photoredox C(sp2)−H Difluoroalkylation and Perfluoroalkylation of Hydrazones
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Dr. Jin Xie M. Sc. Tuo Zhang M. Sc. Fei Chen M. Sc. Nina Mehrkens Dr. Frank Rominger Dr. Matthias Rudolph Prof. Dr. A. Stephen K. Hashmi 《Angewandte Chemie (International ed. in English)》2016,55(8):2934-2938
The first gold‐catalyzed photoredox C(sp2)?H difluoroalkylation and perfluoroalkylation of hydrazones with readily available RF?Br reagents is reported. The resulting gem‐difluoromethylated and perfluoroalkylated hydrazones are highly functionalized, versatile molecules. A mild reduction of the coupling products can efficiently produce gem‐difluoromethylated β‐amino phosphonic acids and β‐amino acid derivatives. In mechanistic studies, a difluoroalkyl radical intermediate was detected by an EPR spin‐trapping experiment, indicating that a gold‐catalyzed radical pathway is operating. 相似文献