Article
Chemistry, Physical
Julia B. Curley, Nicholas E. Smith, Wesley H. Bernskoetter, Mehmed Z. Ertem, Nilay Hazari, Brandon Q. Mercado, Tanya M. Townsend, Xiaoping Wang
Summary: The iron pincer complex ((PNP)-P-iPr)Fe(H)(CO) is an active catalyst, but rapid decomposition limits its performance. Analysis suggests that catalytic intermediates may decompose via a bimolecular pathway, leading to the formation of dimeric species. The study provides strategies for improving catalysis and enhancing the performance of the catalyst in formic acid dehydrogenation.
Review
Nanoscience & Nanotechnology
Q. Zhu, Y. Cui, Y. Zhang, Z. Cao, Y. Shi, J. Gu, Z. Du, B. Li, S. Yang
Summary: MXenes are two-dimensional transition metal carbides, nitrides, and carbonitrides with high catalytic potential due to their unique properties. Various engineering strategies, such as termination engineering and atomic engineering, can enhance the catalytic performance of MXenes. Mechanistic studies and advanced in situ techniques are important for understanding the catalytic activity and active sites of MXenes.
MATERIALS TODAY NANO
(2021)
Article
Chemistry, Physical
Guoyu Shi, Tetsuro Tano, Toshio Iwataki, Donald A. Tryk, Makoto Uchida, Akihiro Iiyama, Kazuki Terao, Kayoko Tamoto, Miho Yamaguchi, Kenji Miyatake, Katsuyoshi Kakinuma
Summary: In this study, a high-performance and durable anion-exchange membrane water electrolysis method is demonstrated using a NiCoMo-based anode catalyst with a crystalline metal core and an amorphous oxide surface. The resulting electrolyzer exhibits high activity and stability, surpassing even state-of-the-art proton-exchange membrane electrolysis using noble-metal catalysts.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Christof Bauer, Felix Mueller, Sercan Keskin, Mirijam Zobel, Rhett Kempe
Summary: This study presents a synthesis protocol for generating nanostructured earth abundant metal catalysts, which are efficient and selective in mediating important chemical reactions. By pyrolysis of an inexpensive metal precursor, an easy to synthesize N/C precursor, and a porous support material, the catalyst material can be obtained in a simple, single synthesis step. The application of this catalyst synthesis method successfully produced a highly active cobalt catalyst for the general and selective hydrogenation of aromatic heterocycles, with implications in organic synthesis and hydrogen storage.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Liu Yang, Huibing Liu, Zelong Qiao, Panpan Sun, Danyang Li, Run Jiang, Shengwen Liu, Ziqiang Niu, Yongguang Zhang, Ting Lin, Qinghua Zhang, Lin Gu, Shitao Wang, Dapeng Cao, Zhongwei Chen
Summary: In this study, a metal-free carbon catalyst NDPC-1000 with a graphitic N-regulating defect structure was designed for anion-exchange membrane fuel cells (AEMFCs) through theoretical calculations and experiments. The graphitic N was found to tailor the charge density of defects to enhance the adsorption energy-activity relation, and the high durability was attributed to the dissociation energy of the C-N covalent bond. The synthesized NDPC-1000 demonstrated excellent ORR activity and durability in alkaline media, achieving a peak power density of 913 mW cm(-2) and a voltage decay of approximately 25% after 100 hours of continuous operation.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Jumpei Hirose, Takumi Wakikawa, Shun Satake, Masahiro Kojima, Manabu Hatano, Kazuaki Ishihara, Tatsuhiko Yoshino, Shigeki Matsunaga
Summary: The enantioselective intramolecular oxyamination of unsaturated alkoxyamines was achieved using a hybrid catalytic system consisting of Cp*Rh-III/chiral disulfonate/CuOAc, leading to tetrahydrofuran derivatives with a tetrasubstituted chiral center in high enantioselectivity. The use of a sterically hindered chiral disulfonate and a Cu additive was crucial for the success of the reaction.
Review
Chemistry, Physical
Xingyuan Gao, Yili Wen, Rui Tan, Haiqing Huang, Sibudjing Kawi
Summary: In this review, the issue of catalyst deactivation in thermo-catalytic hydrogen production from methane is discussed, and six modification strategies to achieve a robust catalyst are proposed. The reaction mechanisms of seven methane-involved reactions and three deactivation mechanisms are illustrated. Furthermore, a critical analysis of the synthesis-structure-performance relationship is provided, and conclusive remarks and prospects are proposed.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Juntao Liu, Jiayan Du, Feng Yu, Lan Gan, Guixia Liu, Zheng Huang
Summary: We designed and synthesized cobalt complexes of L2X-type ligands for olefin hydroboration while considering catalyst stability. The complex with iPr phosphinosubstituents showed broad scope, high functional group tolerance, and high catalytic activity in the hydroboration of terminal olefins with pinacolborane. It demonstrated selectivity for linear hydroboration reactions at elevated temperatures, including with olefins conjugated with arene or carbonyl groups that were difficult to achieve with previous catalysts.
Article
Chemistry, Multidisciplinary
Gregory L. Tate, Bahareh Alsadat Tavakoli Mehrabadi, Wen Xiong, Adam Kenvin, John R. Monnier
Summary: Controlled deposition of metals is crucial for the creation of bimetallic catalysts with predictable composition. Continuous co-electroless deposition allows for the creation of bimetallic catalysts with control over composition, as demonstrated in the study on Cu-Pt mixed-metal shell catalysts for methanol electrooxidation. The ability to control the composition of bimetallic shells can be extended to other systems where the ratio of two metals is critical for catalytic performance.
Article
Chemistry, Physical
Xinhao Wang, Zhaokun Xiong, Hongle Shi, Zelin Wu, Bingkun Huang, Heng Zhang, Peng Zhou, Zhicheng Pan, Wen Liu, Bo Lai
Summary: Rationally regulating reaction mechanisms in Fenton-like reactions by tuning the properties of catalysts is challenging but significant. Various catalysts with different active center sizes were synthesized to realize the switching of reaction mechanisms and pollutant degradation routes in peroxymonosulfate (PMS) activation systems. The transformation of reaction mechanism from radical oxidation to nonradical oxidation was observed with the decrease of active center size. The toxicity tests indicated that the conversion from non-selective to selective oxidation resulted in lower toxicity of effluent after reaction, reducing environmental risks.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Shaohua Chen, Rui Chen, Zhipeng Su, Huan Wang, Xueyin Zhang, Tiehong Chen
Summary: A novel strategy was implemented to create a new type of highly active and stable Mn4+-O-PdOx center by doping Pd into SmMn2O5 lattice and modifying it with acid etching. Compared with the impregnation-method, the catalyst synthesized by this strategy exhibited significantly improved catalytic performance for CH4 combustion, with a reduced T50 and increased TOF value, as well as superior thermal stability and water resistance.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Physical
Boyang Zhang, Jing Liu, Wanqin Yu, Jie Gao, Xuejing Cui, Luhua Jiang
Summary: In this study, a novel core-shell structured Pt@NC/C catalyst was developed, with ultrafine Pt nanoparticles as the core and ultra-thin nitrogen-doped carbon layers as the shell. The catalyst exhibited excellent activity for the alkaline hydrogen oxidation reaction, with high mass activity and specific activity. Moreover, it showed good anti-CO poisoning ability. The interaction between Pt and the carbon layer enhanced hydroxyl adsorption, promoting reaction kinetics and improving CO resistance. This work provides a facile and feasible strategy for designing efficient and CO-resistant Pt-based catalysts.
APPLIED SURFACE SCIENCE
(2023)
Review
Chemistry, Physical
Pradnya M. Bodhankar, Pradip B. Sarawade, Gurwinder Singh, Ajayan Vinu, Dattatray S. Dhawale
Summary: This review discusses the potential of using highly active nickel-iron layered double hydroxide (NiFe LDH) catalyst for electrochemical water splitting and offers recommendations for improving its performance through various methods. NiFe LDH catalysts show promise in the future hydrogen economy.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
Article
Chemistry, Multidisciplinary
Haifeng Zheng, Yingjie Fan, Abigail L. Blenko, Wenbin Lin
Summary: Here, we report the synthesis of a bifunctional photocatalyst, Zr-OTf-EY, by modifying metal cluster nodes in a metal-organic layer (MOL). Zr-OTf-EY with eosin Y and strong Lewis acids on the nodes, catalyzes cross coupling reactions between C-H compounds and electron-deficient alkenes or azodicarboxylate to produce C-C and C-N coupling products, with high turnover numbers. The proximity between photostable EY sites and Lewis acids on the nodes enhances the catalytic efficiency by about 400 times compared to the homogeneous counterpart in the cross-coupling reactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Yanping Chen, Lixuan Ma, Riguang Zhang, Runping Ye, Wei Liu, Jiatong Wei, Vitaly V. Ordomsky, Jian Liu
Summary: This study reports the design of a low-cost and scalable carbon-supported iron catalyst (K-Fe/NC) with tunable alcohol selectivity in Fischer-Tropsch synthesis. The catalyst exhibits a core-shell structure and facilitates the investigation of iron structural evolution. The dissociation and association of CO are thoroughly verified through theoretical calculations and experimental reactions. The synergistic effect between chi-Fe5C2/epsilon-Fe2C and Fe3O4 dual active sites is proposed as the mechanism for alcohol formation.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Review
Chemistry, Multidisciplinary
Nicholas E. S. Tay, Dan Lehnherr, Tomislav Rovis
Summary: Redox processes play a crucial role in synthetic methods involving electrochemistry and photoredox catalysis. Both approaches offer access to high energy intermediates that allow for unconventional bond formations. However, while they provide similar intermediates, electrochemistry and photoredox catalysis differ in their physical chemistry principles. Understanding these differences is essential for designing new transformations and bond disconnections.
Article
Chemistry, Organic
Yining Ji, Cecilia Bottecchia, Francois Levesque, Karthik Narsimhan, Dan Lehnherr, Jonathan P. McMullen, Stephen M. Dalby, Kai-Jiong Xiao, Mikhail Reibarkh
Summary: A detailed mechanistic understanding of the benzylic photobromination reaction has been achieved, revealing both ionic and radical pathways. The behavior of the major reaction species has been elucidated. This knowledge enabled the development of a robust photochemical continuous flow process for commercial manufacturing.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Wen Zhang, Lingxiang Lu, Wendy Zhang, Yi Wang, Skyler D. Ware, Jose Mondragon, Jonas Rein, Neil Strotman, Dan Lehnherr, Kimberly A. See, Song Lin
Summary: Recent research in medicinal chemistry has found a correlation between an increase in sp(3) carbons in drug candidates and their improved success rate in clinical trials. This study focuses on the development of robust and selective methods for constructing carbon(sp(3))-carbon(sp(3)) bonds. By using electrochemistry, the researchers achieve the selective activation of alkyl halides based on their electronic and steric properties, allowing for high selectivity in carbon(sp(3))-carbon(sp(3)) cross-electrophile coupling. This new protocol shows improved chemoselectivity and does not require a transition metal catalyst.
Article
Chemistry, Applied
Cecilia Bottecchia, Francois Levesque, Jonathan P. McMullen, Yining Ji, Mikhail Reibarkh, Feng Peng, Lushi Tan, Glenn Spencer, Jarod Nappi, Dan Lehnherr, Karthik Narsimhan, Michael K. Wismer, Like Chen, Yipeng Lin, Stephen M. Dalby
Summary: We present the development and scale-up of a continuous flow photochemical benzylic bromination process for the synthesis of belzutifan (MK-6482), a drug used for treating renal cell carcinoma associated with Von Hippel-Lindau syndrome. This photochemical approach eliminates the need for azo radical initiators and operates at ambient temperature. By implementing continuous flow technology, we achieved precise control over irradiation and residence time, resulting in a robust process with minimal byproduct formation. This method was selected for the manufacturing process of belzutifan and serves as the first commercial continuous flow photochemical process in our company, setting the foundation for the utilization of photochemistry in the pharmaceutical industry.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2022)
Article
Chemistry, Physical
Ilias Papadopoulos, S. Rajagopala Reddy, Pedro B. Coto, Dan Lehnherr, Dominik Thiel, Michael Thoss, Rik R. Tykwinski, Dirk M. Guldi
Summary: In this study, the impact of excitation wavelength, conformational flexibility, and vibronic coupling on singlet fission was investigated by placing two pentacene chromophores at the termini of a diacetylene linker. The results showed that regardless of temperature, the lifetime for the spin-correlated and vibronically coupled triplet pair (1)(T1T1)(deloc) generated from the low-energy absorption was less than 2 ps. On the other hand, the (1)(T1T1)(deloc) formed from the high-energy absorption lasted 1.0 ps and then decayed via triplet-triplet annihilation within 4 ps at room temperature. Lowering the temperature enabled the (1)(T1T1)(deloc) to delocalize and vibronically decouple, forming (l)(T1T1)(loc). Furthermore, the study suggested that the quasi-free rotation at the diacetylene spacer may lead to twisted conformations with very low singlet fission quantum yields, emphasizing the importance of controlling this structural aspect in the design of new singlet fission active molecules.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Haifeng Yang, Zheng Huang, Dan Lehnherr, Yu-hong Lam, Sumei Ren, Neil A. Strotman
Summary: By employing a combination of an organophotoredox catalyst and Wilkinson's catalyst, a novel method for hydrogen-isotope exchange of aliphatic C(sp3)-H bonds in complex pharmaceuticals using T2 gas directly has been developed. The combination of photocatalysis and Rh catalysis allows carbon-centered radicals generated via photoredox catalysis to be intercepted by Rh-hydride intermediates, providing an effective hydrogen atom donor for isotope labeling of complex molecules in one step.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Applied
Cecilia Bottecchia, Dan Lehnherr, Francois Levesque, Mikhail Reibarkh, Yining Ji, Vailankanni L. Rodrigues, Heather Wang, Yu-hong Lam, Thomas P. Vickery, Brittany M. Armstrong, Keith A. Mattern, Kevin Stone, Michael K. Wismer, Andrew N. Singh, Erik L. Regalado, Kevin M. Maloney, Neil A. Strotman
Summary: Organic electrosynthesis is a rapidly growing field that provides powerful methods for assembling targeted compounds in organic synthesis. However, concerns about scalability have limited its implementation in the pharmaceutical industry. In this study, a workflow was developed to successfully scale up an organic electrosynthetic method from milligram to kilogram scale. By using online flow nuclear magnetic resonance spectroscopy, offline ion chromatography, cyclic voltammetry, and density functional theory calculations, the reaction mechanism and side reactions were elucidated.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2022)
Article
Chemistry, Inorganic & Nuclear
Medina Afandiyeva, Abhishek A. Kadam, Xijue Wu, William W. Brennessel, C. Rose Kennedy
Summary: This paper describes a family of anionic, formally nickel(0) complexes supported by bidentate NHC-pyridone ligands. These complexes have an unsymmetric chelating environment and a capping [K(18-crown-6)]+ countercation, allowing for isolation of single-component, monometallic complexes in high yield. The steric and electronic properties are evaluated using experimental (NMR, IR, UV-vis, X-ray diffraction) and computational tools. Catalytic activity for highly branched-selective hydroboration of styrene with HBpin is demonstrated. Control experiments suggest that the pyridone plays an important role in establishing reactivity and regioselectivity, indicating the potential to utilize secondary coordination sphere effects for reagent activation and delivery with these single-component precatalysts.
Article
Chemistry, Organic
Dalton J. Hanaway, C. Rose Kennedy
Summary: Recent theoretical work and experiments have provided a strong conceptualization for the effects of oriented electric fields (OEFs) on organic reactions. However, evaluating reaction sensitivity to field effects has been inefficient in practice. This study presents the development of an automated tool, A.V.E.D.A, for efficient evaluation of a reaction's susceptibility to OEFs.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Zachary W. Schroeder, Robert McDonald, Michael J. Ferguson, Wesley A. Chalifoux, Rik R. Tykwinski, Dan Lehnherr
Summary: A general method for the synthesis of ethynylated pentacene ketones is reported, and key noncovalent interactions contributing to their crystallization are revealed by X-ray crystallography.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Velabo Mdluli, Dan Lehnherr, Yu-hong Lam, Yining Ji, Justin A. Newman, Jungchul Kim
Summary: A photochemical synthetic method for the synthesis of sulfones from aryl halides and sodium alkylsulfinates in the presence of CuCl is described. The sulfonylation of polyhalogenated arenes exhibits regio- and chemoselectivity. Mechanistic studies suggest the formation of a copper sulfinate reagent in situ from CuCl and sodium sulfinate, as evidenced by NMR experiments. Density functional theory calculations reveal energetically accessible non-planar triplet geometries for potential reaction intermediates, including excited state aryl halides.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Engineering, Chemical
Benjamin Cohen, Dan Lehnherr, Melda Sezen-Edmonds, Jacob H. Forstater, Michael O. Frederick, Lin Deng, Antonio C. Ferretti, Kaid Harper, Moiz Diwan
Summary: The challenges and opportunities in API manufacturing processes are increasing due to the growing molecular complexity, shorter process development times, and the need for greener, more efficient, and less costly processes. However, emerging chemical technologies such as electrochemistry, photochemistry, and biocatalysis offer potential solutions. The Enabling Technology Consortium (ETC) is working to bridge the gap between laboratory-scale development and industrial-scale manufacturing by focusing on these technologies and addressing issues related to scalability, safety, and quality.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Editorial Material
Chemistry, Multidisciplinary
Abhishek A. Kadam, C. Rose Kennedy
Summary: Recently, the Chu/Szymczak and Drover groups independently reported the synthesis and characterization of nickel(0) complexes with distinct boron-containing bisphosphines. These complexes were used for elegant secondary-sphere activation of Lewis basic substrates: organoazides and nitriles. The reports provide insights into strategies for secondary-coordination-sphere activation and highlight areas for further innovation.
TRENDS IN CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Rachel N. N. Motz, Alexandra C. C. Sun, Dan Lehnherr, Serge Ruccolo
Summary: Mechanistic information on photoredox reactions has provided insights for optimization and discovery of synthetic pathways. This report presents a high-throughput method using fluorescence plate readers and 96-well plates to rapidly obtain Stern-Volmer constants, which are crucial for mechanistic understanding. This new method allows for the efficient collection of quenching constants for a library of photocatalysts and quenchers, facilitating systematic comparisons and informing the design of catalytic photoredox reactions.
ACS ORGANIC & INORGANIC AU
(2023)
Article
Chemistry, Inorganic & Nuclear
Sarah M. Craig, Kaycie R. Malyk, Elliot S. Silk, Daniel T. Nakamura, William W. Brennessel, C. Rose Kennedy
Summary: In the past decade, N-heterocyclic carbene, bipyridine, and pyridine oxazoline ligands have been increasingly used in nickel catalysis. The combination of a low-oxidation-state 3d metal and an electron-rich ligand allows for challenging bond activations. This study reports the synthesis and characterization of two Ni(0) complexes supported by a novel bidentate C,N ligand, (h)IMesPy, which shows potential for overcoming reactivity challenges.
JOURNAL OF COORDINATION CHEMISTRY
(2022)
