Article
Chemistry, Multidisciplinary
Thi Minh Thi Le, Thibaud Bregent, Philippe Jubault, Thomas Poisson
Summary: In this study, we revealed the contra-thermodynamic E -> Z isomerization of alkenyl silanes by in situ formation of a chromophoric species, using rac-BINAP as the catalyst. The reaction, carried out in DMSO or CH3CN under irradiation at 405 nm, achieved the interconversion of E-isomers into Z-congeners with good to excellent yields and outstanding Z/E selectivities in 18 examples. Finally, the mechanism of the E -> Z isomerization was investigated to gain insights into the reaction mechanism.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Corentin Cruche, William Neiderer, Shawn K. Collins
Summary: Rare energy-transfer processes involving copper complexes were explored in this study. By utilizing the optimized heteroleptic copper complex Cu(bphen)(XantPhos)BF4, photosensitized E -> Z isomerization of olefins was demonstrated. The XantPhos ligand provided sensitizers with improved catalyst stability, and the bphen ligand lengthened the excited-state lifetime. Successful photoisomerization reactions were conducted on a series of 25 di- and trisubstituted alkenes.
Article
Biochemistry & Molecular Biology
Marvin Korff, Tiffany O. Paulisch, Frank Glorius, Nikos L. Doltsinis, Bernhard Wuensch
Summary: In this study, natural product (E)-anethole was successfully isomerized to (Z)-anethole using a self-designed cheap photoreactor. The selection of an appropriate photosensitizer, Ir(p-tBu-ppy)(3), was supported by theoretical predictions of the triplet energies of (E)- and (Z)-anethole. The reaction achieved high conversion with a catalyst loading of only 0.1 mol% and mild irradiation conditions. Diastereomerically pure diols with different configurations were obtained through dihydroxylation.
Article
Chemistry, Multidisciplinary
Xiao-Xu Liu, Yang Li, Xin Li, F. Ekkehardt Hahn, Ying-Feng Han
Summary: The study demonstrates a unique isomerization process of E-TPE derivative into its Z-isomer through metal complex formation/irradiation/demetallation, which cannot be achieved by irradiation of the individual imidazolium salt.
SCIENCE CHINA-CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Taotao Hao, Yongsheng Yang, Wenting Liang, Chunying Fan, Xin Wang, Wanhua Wu, Xiaochuan Chen, Haiyan Fu, Hua Chen, Cheng Yang
Summary: Mild acid-catalyzed Z→E isomerization was discovered in stilbene derivatives fused with a norbornene moiety, inhibiting undesired by-reactions and allowing orthogonal control through light and acid. The isomerization process could be controlled by turning on/off photoacid irradiation, and the Z isomer produced by photoisomerization could self-recover to the E isomer in the presence of a catalytic amount of acid. This study realized unprecedented molecular photoswitches with adjustable self-recovery kinetics by manipulating catalytic factors.
Article
Chemistry, Organic
Maxim R. Radzhabov, Neal P. Mankad
Summary: A cobalt-catalyzed method has been developed for the hydrogermylation of alkynes, providing a selective and accessible route to (E)-beta-vinyl(trialkyl)germanes. The method demonstrates broad functional group tolerance and practical utility for late-stage hydrogermylation of natural products. Mechanistic studies support the syn-addition of Bu3GeH to an alkyne pi-complex.
Article
Food Science & Technology
Qun Wang, Cheng Yang, Yuanyuan Liu, Jian Zhang, Lianfu Zhang
Summary: This study screened the effects of eleven metal salts on the isomerization and stability of lycopene and found that AlCl3 exhibited significant catalytic effects and high production. All five metal salts reduced the activation energy of lycopene isomerization and degradation reactions.
LWT-FOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Chemistry, Physical
Yao Yao, Yuan Yu, Ming-Liang Shi, Ru -De Lin, Kun Li, Na Wang
Summary: A facile and high efficiency photo-enzyme catalysis system has been developed for the E to Z isomerization of alkenes. The system showed good versatility and achieved synthesis of 43 Z-configurations of alpha, beta-unsaturated esters and stilbenes in good yields, with the highest Z/E ratio being 91:9. The photo-enzyme catalysis system has wide substrate range, mild reaction conditions, simple operation, and is in line with atom-economic synthesis.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Organic
Ruben Falkenburg, Maximilian J. Notheis, Gregor Schnakenburg, Larissa K. S. von Krbek
Summary: Incorporating azobenzenes into macrocycles is an interesting method for adjusting the photophysical properties and customizing them for specific applications. A versatile synthesis method has been developed, enabling easy modification of these photoswitches. One example exhibits high chemical stability, long half-life of its Z-isomers, near quantitative Z -> E conversion under white light, and excellent separation of excitation bands to selectively address the E or Z state.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Thibaud Bregent, Jean-Philippe Bouillon, Thomas Poisson
Summary: The photocatalytic contra-thermodynamic E -> Z isomerization of vinyl boronates can be achieved using a binaphthol catalyst. The reaction proceeds through the transient formation of a suitable chromophore with a BINOL derivative as the catalyst, resulting in good-to-excellent Z/E ratio and excellent-to-quantitative yields. The mechanism involves the formation of a transient chromophore species.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Gabriel Glotz, Konstantin Knaipp, Martin S. Maier, Katharina Hull, Alexander Novak, Anne-Marie Kelterer, Thomas Griebenow, Rainer Herges, Dirk Trauner, Georg Gescheidt
Summary: The size of the central ring in 1,2-diazocines and diazonines influences the configuration of the one-electron reduced species. Diazonines with a central nine-membered heterocycle exhibit light-induced E/Z isomerization, while retaining the configuration of the diazene N=N moiety upon one-electron reduction. Therefore, E/Z isomerization is not induced by reduction.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Qiong Yu, Kun Yi Yu, Cai Feng Xu, Man-Kin Wong
Summary: An efficient visible light photocatalytic strategy was developed for synthesizing thermodynamically less stable Z-arylvinyl halides. The reaction involved base-mediated halodecarboxylation of E-arylvinyl acids and visible light Ir-photocatalyzed isomerization of E-arylvinyl halides in a one pot sequential catalytic process, resulting in high yields and high Z/E ratios.
Article
Chemistry, Multidisciplinary
Jinguo Long, Ruihua Zhao, Gui-Juan Cheng, Xianjie Fang
Summary: A palladium-catalyzed hydrocyanation of propiolamides for the stereodivergent synthesis of trisubstituted acrylonitriles is described. The method can tolerate various primary, secondary, and tertiary propiolamides. The selection of a suitable ligand is crucial for the success of this stereodivergent process. Control experiments indicate the intermediacy of E-acrylonitriles, which undergo isomerization to form Z-acrylonitriles. Density functional theory calculations suggest that the bidentate ligand L2 enables a feasible cyclometallation/isomerization pathway for the E to Z isomerization, while the monodentate ligand L1 inhibits the isomerization, leading to divergent stereoselectivity. The usefulness of this method is demonstrated by the facile derivatization of products to give various E- and Z-trisubstituted alkenes. Additionally, the E- and Z-acrylonitrile products have been successfully employed in cycloaddition reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Munshi Sahid Hossain, Subhajit Bandyopadhyay
Summary: A pair of new macrocyclic azobenzenes have been thoroughly characterized and one compound shows quantitative conversion from the E- to the Z-form, as well as an unusual instant switching from the Z-form to the E-isomer in the presence of Cu2+ ions in the dark. The Cu2+ complex can remain in the Z-form under constant UV radiation, reverting to the E-form once UV exposure ceases.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Willibald J. Stockerl, Ruth M. Gschwind
Summary: This article describes the observation and assignment of high energetic (Z)-configured intermediates in imidazolidinone iminium ions through in situ photoisomerization. Stabilization conditions for (E,Z) and (Z,Z) isomers were also determined.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Jessica Neufeld, Constantin. G. G. Daniliuc, Ryan Gilmour
Summary: This study presents a regioselective fluorocyclisation of beta,gamma-unsaturated oximes through I(I)/I(III) catalysis, using p-iodotoluene as a cost-effective catalyst, Selectfluor((R)) as the oxidant, and an amine.HF complex as the fluoride and Bronsted acid source. The transformation produces 5-fluoromethylated isoxazolines, with a range of aliphatic and aromatic systems yielding up to 56%.
HELVETICA CHIMICA ACTA
(2023)
Article
Chemistry, Medicinal
Tobias Schierling, Beatrice Tosi, Clara Eisenhardt, Sophie Reining, Constantin G. Daniliuc, Christoph Brenker, Timo Struenker, Bernhard Wuensch
Summary: This article introduces a new and more effective inhibitor for studying sperm swimming behavior. The inhibitor is structurally simpler and easier to synthesize compared to existing inhibitors, and shows even better potency. It is envisioned to be widely used in future studies on the physiology of CatSper in sperm.
ACS PHARMACOLOGY & TRANSLATIONAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Yujie Liang, Fritz Paulus, Constantin G. Daniliuc, Frank Glorius
Summary: We report a BF3-catalyzed [2 + 2] cycloaddition reaction between aldehydes and bicyclo[1.1.0]butanes (BCBs) to access polysubstituted 2-oxabicyclo[2.1.1]hexanes. A new BCB containing an acyl pyrazole group was discovered, which not only facilitates the reactions but also allows for diverse downstream transformations. Additionally, aryl and vinyl epoxides can be used as substrates that undergo cycloaddition with BCBs after in situ rearrangement to aldehydes. These results will promote the exploration of complex sp(3)-rich bicyclic frameworks and BCB-based cycloaddition chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Jannik Reimler, Xiao-Ye Yu, Nico Spreckelmeyer, Constantin G. Daniliuc, Armido Studer
Summary: The Friedel-Crafts acylation reaction has been a valuable and versatile reaction, but a new radical approach for the acylation of arenes and heteroarenes is presented in this study. By using cooperative photoredox/NHC radical catalysis, C-H acylation is achieved with regiodivergent outcomes. Aroyl fluorides act as the acylation reagents in both the ionic and radical processes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Max Wienhold, Byeongseok Kweon, Calum McLaughlin, Matthias Schmitz, Till J. B. Zaehringer, Constantin G. Daniliuc, Christoph Kerzig, Ryan Gilmour
Summary: Amide groups are widely present in the chemical space continuum, and their structural and pharmacological importance as well as hydrolytic vulnerabilities drive the development of bioisosteres. Alkenyl fluorides have a long history as effective mimics, but emulating peptide bond isomerization with fluoro-alkene surrogates is challenging. This study presents a design of an ambiphilic linchpin that enables isomerization process, providing geometrically-programmable building blocks for small molecule amide and polyene isostere discovery.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Gina Vasile Scaeteanu, Constantin G. Daniliuc, Rodica Olar, Mihaela Badea
Summary: A complex [Zn(bpy)(acr)(2)]center dot H2O was converted into a coordination polymer [Zn(bpy)(acr)(HCOO)](n) in a DMF medium. The polymer was fully characterized through crystallographic analysis, IR, and thermogravimetric analysis. The obtained complex, with its unique composition and structure, is of current interest and rarely reported in the literature.
Article
Chemistry, Multidisciplinary
You-Jie Yu, Joel Haefliger, Zi-Xuan Wang, Constantin G. Daniliuc, Ryan Gilmour
Summary: A main-group catalysis-based strategy for accessing 8-membered carbocycles via direct carbofunctionalization of 2-phenethyl-substituted 1,3-dienes is presented. By utilizing an I(I)/I(III) catalysis cycle, densely functionalized, fluorinated benzocyclooctenes can be synthesized in a straightforward manner. The process, which involves modulation of the oxidation/activation regime and the external nucleophile, has been extended to enable the cyclization with allylic C-O, C-N, and C-C bond formation (>30 examples).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Fabian Hoeglsperger, Fayaz Ali Larik, Changzhuang Bai, Maximilian D. Seyfried, Constantin Daniliuc, Henning Klaasen, Pall Thordarson, Jonathon E. Beves, Bart Jan Ravoo
Summary: In this study, water-soluble arylazoisoxazole photoswitches were introduced. The photostationary states and reversible photoisomerization between E- and Z-isomers were observed, indicating their potential for photoresponsive host-guest chemistry in water. Furthermore, hydrogel properties can be manipulated reversibly with light. Overall, arylazoisoxazoles have great potential as molecular photoswitches in aqueous media.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Till J. B. Zaehringer, Max Wienhold, Ryan Gilmour, Christoph Kerzig
Summary: This study provides a rigorous mechanistic investigation of the photoisomerization of alkenylboronates. The detection and characterization of the perpendicular triplet generated by energy transfer through a combination of experiments, spectroscopic studies, kinetic modeling, and DFT calculations have been achieved. The findings have not only served as a blueprint for challenging mechanistic studies but also allowed for the development of more sustainable reaction conditions, enabling efficient organocatalytic isomerization under sunlight irradiation for the first time.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Zi-Xuan Wang, Keith Livingstone, Carla Huempel, Constantin G. Daniliuc, Christian Mueck-Lichtenfeld, Ryan Gilmour
Summary: Fluorinated small molecules are commonly used in the field of functional small molecules. Researchers have developed creative approaches to access these important materials by utilizing iodine(I)/iodine(III) catalysis to convert abundant alkene substrates into high-value (di)fluorinated products. They also discovered that enynes can be used as proxies for styrenes, simplifying the process and enabling the generation of highly versatile homopropargylic difluorides.
Article
Chemistry, Organic
Shyam Kumar Banjare, Dirk Leifert, Frauke Weidlich, Constantin G. Daniliuc, Fatmah A. Alasmary, Armido Studer
Summary: An oxidative radical cascade addition cyclization approach using eco-friendly iron catalysis and inexpensive tert-butylhydroperoxide (TBHP) as the oxidant has been reported for the synthesis of quinoline-based p-extended polyheterocyclic compounds. This method utilizes readily available ortho-alkynylated aromatic aldehydes as radical precursors and aryl isonitriles as radical acceptors. By applying this approach, quinolines that are p-conjugated with an additional heteroarene moiety can be prepared in a single sequence using indole and thiophene-based carbaldehydes.
Article
Multidisciplinary Sciences
Huamin Wang, Huiling Shao, Ankita Das, Subhabrata Dutta, Hok Tsun Chan, Constantin Daniliuc, K. N. Houk, Frank Glorius
Summary: In this study, a photoinduced ring enlargement method of thiophenes was developed, which involves the insertion of bicyclo[1.1.0]butanes to form eight-membered bicyclic rings under mild conditions. The synthetic value, broad functional-group compatibility, and excellent chemo- and regioselectivity were demonstrated by scope evaluation and product derivatization. Experimental and computational studies suggested a photoredox-induced radical pathway.
Review
Chemistry, Multidisciplinary
Emma Campbell, Christina Jordan, Ryan Gilmour
Summary: Carbohydrate diversity plays a crucial role in regulating cellular function and communication, making it an important area of research in biomedical diagnostics. The radiotracer 2-[F-18]-FDG, which utilizes metabolic trapping, has shown great success in positron emission tomography (PET). More complex sugars with specific selectivities are now being explored for molecular recognition and personalized medicine. This review provides an overview of the development of 2-[F-18]-FDG and glycan-based radiotracers for PET, highlighting their diagnostic functions and assisting in further interdisciplinary research.
CHEMICAL SOCIETY REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Timo Stuenkel, Kathrin Siebold, Daichi Okumatsu, Kazuki Murata, Louise Ruyet, Constantin G. Daniliuc, Ryan Gilmour
Summary: The regio- and enantio-selective dearomatization of phenols has been achieved using I(i)/I(iii) catalysis enabled fluorination. The reaction is highly selective and efficient, offering great potential in the field of hydroxylation chemistry.