Article
Chemistry, Multidisciplinary
Utku Yolsal, Thomas A. R. Horton, Meng Wang, Michael P. Shaver
Summary: Sterically hindered Lewis acid and base centers form frustrated Lewis pairs (FLPs) instead of Lewis adducts, allowing for activation of small molecules. By applying FLP chemistry to polymeric frameworks, responsive and functional materials can be created. A versatile synthesis strategy for macromolecular FLPs has been developed, with potential demonstrated through ring-opening reactions of cyclic ethers in polymer networks. The steric and electronic properties of the ethers can tune the cross-linking, strength, and reactivity of the networks, showcasing the versatility of FLPs in simultaneously controlling small-molecule capture and mechanical properties of materials.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Karel Skoch, Constantin G. Daniliuc, Gerald Kehr, Gerhard Erker
Summary: The compound undergoes a rare reaction with a borane to form a unique unsaturated compound, capable of reducing carbon monoxide and reacting with nitriles to produce a boron-containing heterocycle derivative.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Benedikt Sieland, Axel Hoppe, Arne J. Stepen, Jan Paradies
Summary: A frustrated Lewis pair-catalyzed hydroboration of aromatic and aliphatic nitriles was developed, providing primary amines in high yields with low catalyst loading. The reaction exhibits high functional group tolerance and Z-selectivity.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Laura Koering, Nikolai A. Sitte, Markus Bursch, Stefan Grimme, Jan Paradies
Summary: The metal-free catalytic hydrogenation of secondary carboxylic acid amides is achieved through two new catalytic reactions, involving the conversion of amides into imidoyl chlorides and the subsequent hydrogenation of the generated chlorides by an FLP-catalyst. Mechanistic and quantum mechanical calculations support the unique role of chloride as a Lewis base in FLP-mediated H-2-activation during the hydrogenation process.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Xiongfei Zheng, Ili Zulkifly, Andreas Heilmann, Caitilin McManus, Simon Aldridge
Summary: Two BNB-type frustrated Lewis pairs with different B-bound fluoroaryl groups are capable of capturing gaseous CO reversibly at/above room temperature, with migration of an aryl substituent to the electrophilic carbon of the CO guest. This reversibility allows for release of captured carbon monoxide in the temperature range 40-70 degrees C, enabling potential CO sensing based on color changes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Ryo Oshimizu, Naoki Ando, Shigehiro Yamaguchi
Summary: In this study, the weak interaction between olefin-borane pi-complexes and frustrated Lewis pairs (FLP) was utilized to modulate the electronic properties of boron-based pi-electron materials. By adding Lewis bases, FLP-type addition reactions occurred, leading to significant changes in the absorption and emission properties of the fluorophores. These findings offer a design strategy for stimuli-responsive emissive boron-based materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Manjur O. Akram, John R. Tidwell, Jason L. Dutton, Caleb D. Martin
Summary: This passage describes a Lewis superacid called bis(1-methyl-ortho-carboranyl)borane, which can be rapidly synthesized in two steps. It is a highly effective hydroboration reagent capable of B-H addition to alkenes, alkynes, and cyclopropanes. To date, it is the first identified Lewis superacidic secondary borane and the most reactive neutral hydroboration reagent.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Felix Wech, Urs Gellrich
Summary: This review discusses the hydrogenation of organic substrates catalyzed by borane-based frustrated Lewis pairs, with a focus on the mechanistic aspects of these catalytic reactions.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Inorganic & Nuclear
Yanlin Pan, Jie Cui, Yongliang Wei, Zhaochao Xu, Tongdao Wang
Summary: Rare examples of B-H bond activation in a frustrated radical pair regime have been observed by treating TEMPO radicals with Piers' borane. The resulting zwitterionic products and geminal N/B frustrated Lewis pairs imply a one electron process. Our results provide insights into chemical bond activation via a single electron transfer.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Physical
Hailong Xu, Xuedan Song, Miaomiao Chen, Wei Bai, Min Ji
Summary: A novel catalyst FLP/MIL-101(Cr) was designed in this work for the regioselective hydrogenation of a, b-unsaturated carbonyl compounds. The catalyst demonstrated good stability and catalytic performance, achieving high selectivity in the reduction of unsaturated bonds. This study provides an ingenious strategy to design FLP heterogenous catalysts and demonstrates their potential application in selective reduction.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Inorganic & Nuclear
Orhi Esarte Palomero, Richard A. Jones
Summary: The synthesis of novel ferrocene tethered boramidinate frustrated Lewis pairs (FLPs) capable of sequentially capturing small molecules is reported. The reactivity of the boramidinate moieties can be tuned by altering the substituents and borane used in the reduction. Independent small molecule capture by each FLP has been demonstrated, allowing for sequential capture of different gaseous small molecules.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Multidisciplinary
Wei Chen, Jingfeng Han, Yingxu Wei, Anmin Zheng
Summary: The frustrated Lewis pair (FLP) concept has been successfully applied to heterogeneous catalysis by using a supramolecular system involving deprotonated zeolite framework oxygens and confined carbocations in methanol-to-olefin (MTO) reactions. This FLP showed the capability of H-2 heterolysis and alkane dehydrogenation, which was confirmed by catalytic experiments using GC-MS inside FLP-containing chabazite zeolites.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Meng Wang, Jordan Holland, Thomas A. R. Horton, Utku Yolsal, Michael P. Shaver
Summary: The versatile chemistry of boronic acid and boronate ester containing polymers has led to key applications in drug delivery, chemical sensing, and dynamic materials. In this paper, a novel fluorinated borinate ester copolymer was synthesized, which, when combined with a suitable Lewis basic copolymer, generated polymeric FLP networks capable of responsive gelation. The physical parameters and nature of the crosslinks of the gels prepared from different crosslinkers were probed by rheology, demonstrating strong elastic behavior and covalently crosslinked materials.
Article
Chemistry, Physical
Swapan Sinha, Santanab Giri
Summary: In this study, a new frustrated Lewis pair (FLP) was designed to activate the H2O molecule. The activation mechanism and charge transfer processes were thoroughly analyzed and revealed through calculations and analysis.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Haishuai Cui, Linhao Zhong, Xiaoqing Liao, Fang Hao, Wei Xiong, Huajie Liu, Hean Luo, Pingle Liu, Yang Lv
Summary: Zeolitic imidazolate frameworks (ZIFs) were prepared through different methods for the chemoselective hydrogenation of biomass-derived cinnamaldehyde. Defective ZIFs prepared by microwave-assisted method (ZIF-67-MW) exhibited more defects, which led to the formation of a heterogeneous Frustrated Lewis pairs (FLPs) system with independent Lewis acid and Lewis basic sites. Theoretical calculations showed that the FLPs sites in the defective ZIFs had low activation energy for dissociating the H-H bond. A silica-coated and hydrophobically modified core-shell structure (ZIF-67-MW@SiO2-DMDES) was developed to enhance stability and selectivity, achieving high conversion of cinnamaldehyde to cinnamyl alcohol. Substrate-extending experiments demonstrated that ZIF-67-MW@SiO2-DMDES had promising potential in the selective hydrogenation of various unsaturated aldehydes.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Physical
Justin Dubbert, Marco Valtolina, Alexander Huber, Tim D. Scherz, Christoph Woelper, Constantin G. Daniliuc, Ofer Filiba, Saumik Sen, Igor Schapiro, Fabio Rizzo, Jens Voskuhl
Summary: In this study, a series of chlorinated bridged ethers with varying numbers of sulfur and oxygen atoms were synthesized and their tunable photophysical properties in different aggregated states were investigated.
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
Chemistry, Multidisciplinary
Chaohuang Chen, Constantin G. Daniliuc, Gerald Kehr, Gerhard Erker
Summary: The neutral N-heterocyclic carbene stabilized boranotsignalkene 1, prepared by a BH borenium/hydroboration method, can form stable copper, gold, or palladium pi-complexes. The polar boranotsignalkene B=C system undergoes selective hydroboration reactions with (C6F5)(2)BH or C6F5BH2 center dot SMe2 boranes. The latter reaction involves subsequent rearrangement leading to the exchange of internal hydride and isothiocyanate substituents at the borane pair.
CHEMISTRY-A EUROPEAN JOURNAL
(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
Multidisciplinary Sciences
Joel Haefliger, Louise Ruyet, Nico Stuebke, Constantin G. Daniliuc, Ryan Gilmour
Summary: In this article, a cascade reaction is validated to generate novel gem-difluorinated isosteres from 1,3-diaryl cyclobutanols in a single operation, utilizing the biological significance of partially saturated, fluorine-containing rings and the physicochemical advantages conferred by fluorination.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Jonas Elfert, Anup Bhunia, Constantin G. Daniliuc, Armido Studer
Summary: In this study, a radical transformation that enables intramolecular oxygen atom transfer to alkenes using the nitro functionality in nitroarenes as an oxygen donor is disclosed. The reaction proceeds via iron-catalyzed metal hydrogen atom transfer to alkenes and subsequent oxygenation, resulting in alkene hydration. Compared to intermolecular radical oxygenation, the intramolecular variant offers advantages, particularly in terms of diastereoselective radical hydration of conformationally flexible alkenes. The aryl moiety connecting the reactive NO2-functionality to the alkene substrate can be cleaved after oxygen transfer, yielding products derived from a formal diastereoselective intermolecular alkene hydration. Additionally, the resulting aniline entity after oxygen transfer can be used for the construction of nitrogen-containing heterocycles.
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, Physical
Dasharath Kondhare, Xenia Heddinga, Simone Budow-Busse, Constantin Daniliuc, Frank Seela
Summary: The single-crystal X-ray structure of 5-aza-7-deaza-7-iodoguanine 2'-C-methylribonucleoside 1 is described, which was synthesized through stereoselective nucleobase anion glycosylation and subsequent deprotection. The CD-spectrum analysis of 1 revealed the significant impact of the iodo substituent on the molecule. A dye conjugate was generated by Suzuki-Miyaura cross-coupling of 1 with pyrene boronic acid, showing solvent dependent exciplex fluorescence.
JOURNAL OF MOLECULAR STRUCTURE
(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.
