Article
Multidisciplinary Sciences
Peter J. Sempsrott, Brian B. Trinh, Charity Flener Lovitt, Nicolas E. Capra, Gregory S. Girolami
Summary: By studying the structure of methane bound to a transition metal compound, it was found that methane binds to the metal center through a single M center dot center dot center dot H-C bridge, and the structure is significantly different from the free molecule. These results are important for the development of better C -H functionalization catalysts.
Article
Chemistry, Multidisciplinary
Dipendu Mandal, Ting Chen, Zheng-Wang Qu, Stefan Grimme, Douglas W. Stephan
Summary: In this work, we reported the reactions of phosphine/borane FLPs with chlorodiazirines, which resulted in the reduction of the N=N double bond and formation of phosphinimide/amidoborate zwitterions. A mechanistic study using DFT showed that these reactions proceed through FLP addition and subsequent group transfer reactions to nitrogen, followed by the capture of a halide anion.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Vishal Yadav, Maxime A. Siegler, David P. Goldberg
Summary: The study found that non-heme iron complexes exhibit different reactivity with a tertiary carbon radical, providing a new working model for C-S bond formation in isopenicillin N synthase. The results suggest that kinetic control may play a crucial role in the selectivity of non-heme iron rebound processes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Jia-Hui Liu, Xue-Jiao Lv, Yan-Kai Liu
Summary: An asymmetric retro-Claisen reaction of alpha-mono-substituted beta-diketones and quinones (or quinone imine) has been developed using a chiral aza-bisoxazoline-Zn(II) complex as a catalyst. The reaction involves conjugate addition, arylation, hemiketal anion-initiated C-C bond cleavage, and enantioselective protonation of enolate, leading to the formation of functionalized alpha-arylated ketones with a tertiary stereogenic center in high enantioselectivities. Importantly, biologically significant benzofuran and gamma-butyrolactone derivatives can be synthesized using this protocol.
Article
Chemistry, Physical
Bo Zhu, Shigeyoshi Sakaki
Summary: Hydrodefluorination of trifluoromethylstyrene has been achieved through a unique reaction mechanism using a nickel(II) hydride iso-PmBox complex as a catalyst, resulting in the formation of gem-difluoromethylstyrene as the product. The success of this difficult reaction is attributed to the flexibility of the Ni element and the rigidity of the iso-PmBox ligand.
Article
Chemistry, Inorganic & Nuclear
Andrey V. Protchenko, M. Angeles Fuentes, Jamie Hicks, Caitilin McManus, Remi Tirfoin, Simon Aldridge
Summary: The reaction of boryl-substituted stannylene with carbon dioxide proceeds via pathways involving insertion into the Sn-B bonds. Several different products can be derived from this reaction, including boryl(borylcarboxylate)ester and bis(borylcarboxylate) stannylene complexes. The possibility of extrusion of CO from the reaction products to generate boryloxy systems has also been observed.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Applied
Xinyu Du, Xinghao Qi, Kai Li, Xiaoyan Li, Hongjian Sun, Olaf Fuhr, Dieter Fenske
Summary: The novel silylene-supported iron hydride 1 was synthesized via C(sp(3))-H bond activation and exhibited excellent catalytic activity for hydrosilylation of aldehydes and ketones. It showed good tolerance and catalytic activity for substrates with different functional groups on the benzene ring, with both ketones and aldehydes being reduced in good to excellent yields under the same catalytic conditions. A possible catalytic mechanism was proposed based on experiments and literature reports.
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Jiaoyu Wu, Linqiang Li, Mengtian Liu, Lu Bai, Xinjun Luan
Summary: A novel Pd-0-catalyzed [2+2+1] annulation was proposed for the rapid assembly of tricyclic indoles in a single-step transformation. Experimental results showed that large tert-butyl and benzyl groups were selectively cleaved via an S(N)1 pathway in the presence of smaller alkyl groups.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Hong-Tao Zhang, Fei Xie, Yu-Hua Guo, Yao Xiao, Ming-Tian Zhang
Summary: We report the first nonheme CuFe oxygen reduction catalyst, which shows exceptional selectivity and turnover frequency in the reduction of oxygen to water. The collaborative efforts of copper and iron play a crucial role in achieving these outstanding catalytic properties.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Matthew C. Fitzsimmons, Azamat Yessengazin, Gillian P. Hatzis, Jeremiah E. Stevens, Curtis E. Moore, Christine M. Thomas
Summary: A Co(II) complex, ((PPP)-P-H)CoI2, was synthesized and used as a precatalyst for the hydrogenation of terminal alkenes under mild conditions. The catalytic system showed activity towards terminal alkene substrates, including 1,1'-disubstituted alkenes, and exhibited moderate stability in air and moisture. The catalytically active species was identified as a cobalt hydride monomer, [(PPP)CoH](2).
Article
Chemistry, Organic
Yu-Shi Jiang, Shan-Shan Li, Xue-Ling Luo, Li-Ning Chen, Dan-Na Chen, Peng-Ju Xia
Summary: A metal-free difunctionalization strategy for diazenes was developed using bifunctionalization reagents, leading to the construction of over 30 triazane core motifs. This strategy involves a unique N(sp(3))-N(sp(2)) radical coupling between the hydrazine radical and the imine radical, allowing the efficient installation of imines and various functional groups on both ends of the nitrogen-nitrogen bond of diazenes.
Article
Chemistry, Multidisciplinary
Benedek Stadler, Nikolaus Gorgas, Andrew J. P. White, Mark R. Crimmin
Summary: In this work, we report the first double deprotonation of acetonitrile (CH3CN) using a bimetallic iron-aluminium complex. The products of this reaction contain a simple yet rare [CHCN](2-) dianion moiety that bridges two metal fragments. DFT calculations suggest that the bonding to the metal centres occurs through heavily polarised covalent interactions. Mechanistic studies reveal the intermediacy of a monomeric [CH2CN](-) complex, which has been characterised in situ. Our findings provide an important example of a bimetallic metal complex achieving a new type of reactivity not previously encountered with monometallic counterparts. The isolation of a [CHCN](2-) dianion through simple deprotonation of CH3CN also offers the possibility of establishing a broader chemistry of this motif.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Connor P. McLoughlin, James C. Fettinger, Philip P. Power
Summary: Six new transition-metal aryloxides were synthesized and characterized to compare the steric and dispersive characteristics of their substituents. The results show that the -C6H2-2,4,6-Cy-3 substituent has higher dispersive energy donor properties and influences the thermal stability. Complexes 1 and 2 exhibit high thermal stability and short-contact H···H interactions, while complexes 5 and 6 have a lower association number due to the lower dispersion energy donor properties of the -OC6H3-2,6-Pr-i (2) ligand.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Hai-Jun Li, Rui Feng, Gao-Xiang Wang, Junnian Wei, Zhenfeng Xi
Summary: By reacting semi-rigid PNP ligand with CoBr2, complex PNPCoBr (1) was obtained. The reduction of 1 with excess amounts of KC8 in THE under a N-2 atmosphere yielded binuclear cobalt dinitrogen anion complex [Co(mu-Cy2P)PCyN2](2)K (2) by cleaving the C-P bond of the PNP ligand. Adding 2,2,2-cryptand into complex 2 effectively prepared ion pair Co complex, [Co(mu-Cy2P)PCyN2](2)K(crypt-222) (3). The structures of 1, 2, and 3 were determined by single-crystal X-ray diffraction analysis, and N-2 is moderately activated in complexes 2 and 3. DFT calculations suggest the presence of a Co-Co bond in 2 and 3. Compounds 1 and 2 exhibit catalytic activity for the transformation of N-2 to N(SiMe3)(3).
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Multidisciplinary
Nalladhambi Neerathilingam, Ramasamy Anandhan
Summary: An efficient method for the synthesis of imides using metal-free photoredox-catalyzed direct alpha-oxygenation of N,N'-disubstituted anilines has been developed. This method offers operational simplicity, high atom economy, and functional group tolerance under mild reaction conditions.
Review
Biochemistry & Molecular Biology
Prabhuodeyara M. Gurubasavaraj, Vinodkumar P. Sajjan, Blanca M. Munoz-Flores, Victor M. Jimenez Perez, Narayan S. Hosmane
Summary: Organoboron compounds have gained immense research interest due to their wide range of applications. In particular, low-coordinate organoboron complexes have received more attention due to their unique optical and nonlinear optical properties, making them better candidates for medical applications. This review summarizes various synthetic methods and the optical and nonlinear properties of organoboron complexes, as well as their usage in biomedical applications.
Correction
Chemistry, Inorganic & Nuclear
Lauren E. Wenger, Nicholas M. Shawver, Ross E. Koby, William W. Brennessel, Brian K. Long, Timothy P. Hanusa
Article
Chemistry, Multidisciplinary
Eric Schreiber, William W. Brennessel, Ellen M. Matson
Summary: This study investigates the electronic structure of a reduced polyoxovanadate-alkoxide cluster with a bridging oxide moiety. The incorporation of bridging oxide sites quenches the cluster-wide electron delocalization in the most reduced state, resulting in a change in regioselectivity of PCET to the cluster surface. Reactivity localized at the bridging oxide site enables reversible storage of a single H-atom equivalent, altering the stoichiometry of PCET. The findings provide insights into the design of functional materials for energy storage and conversion processes.
Article
Chemistry, Multidisciplinary
Lakkappa B. Anigol, Vinodkumar P. Sajjan, Prabhuodeyara M. Gurubasavaraj, Sharanabasava V. Ganachari, Dhanashree Patil
Summary: The green synthesis of silver nanoparticles using Capparis Moonii fruit extract as a reducing agent was studied for biomedical applications in cancer nanomedicine. The synthesized nanoparticles exhibited a spherical shape with a size range of 10-20 nm. The silver nanoparticles showed cytotoxicity against various cancer cell lines and demonstrated excellent photocatalytic activity for the degradation of rose bengal and methylene blue under sunlight radiation.
Article
Chemistry, Inorganic & Nuclear
Aleksa Radovic, Nikki J. Wolford, Hongze Li, William W. Brennessel, Hao Xu, Michael L. Neidig
Summary: This study focuses on the ligand effects on reactivity and in situ iron speciation in the iron-catalyzed amino-oxygenation of olefins using a bisoxazoline ligand. Experimental results reveal that the ligand and solvent have significant influence on the speciation in the precatalytic mixture, leading to the formation of different species that affect the reactivity. The in situ experiments provide evidence for the formation of an iron iminyl radical species and suggest that the functionalized hydroxylamine identity can dictate the reactivity observed in these reactions.
Article
Chemistry, Physical
Maria Camila Aguilera, Achyut Ranjan Gogoi, Wes Lee, Lei Liu, William W. Brennessel, Osvaldo Gutierrez, Michael L. Neidig
Summary: Iron-bisphosphines have been widely studied as highly effective and versatile catalytic systems for cross-coupling reactions. However, the mechanistic features essential for their catalytic performance are still unclear. In this study, the authors investigate the mechanism of enantioselective coupling reactions catalyzed by chiral bisphosphine-iron complexes. By using various techniques, they reveal the key intermediates and their roles in the catalytic cycle. The study provides important insights into the radical initiation, factors contributing to side product generation, and protocol effects for selective cross-coupling methods.
Article
Chemistry, Inorganic & Nuclear
Thompson V. Marinho, Eric Schreiber, Rachel E. Garwick, William W. Brennessel, Ellen M. Matson
Summary: This paper presents the post-synthetic modification of a polyoxovanadate-alkoxide cluster by reacting its cationic form with water, leading to the synthesis of a series of POV-alkoxide clusters with different mu(2)-O2- ligands at the surface. The characterization of the clusters and investigation of their redox properties were conducted using infrared and electronic absorption spectra as well as cyclic voltammetry.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Christopher D. Hastings, Lucy S. X. Huffman, Chandan Kumar Tiwari, Jolaine Galindo Betancourth, William W. Brennessel, Brandon R. Barnett
Summary: In this study, a synthetic method for a tripodal ligand scaffold is reported, which forms a narrow and rigid cavity through a macrocyclization reaction. The resulting coordination complexes exhibit a narrow cavity and an open metal coordination site. It is shown that acetonitrile entry into the cavity is sterically precluded, disrupting anticipated coordination at the intracavity site. A new tripodal ligand system is used to access unsaturated metallates of cobalt(II), nickel(II), and zinc(II).
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Kaycie R. Malyk, Vivek G. Pillai, William W. Brennessel, Roberto Leon Baxin, Elliot S. Silk, Daniel T. Nakamura, C. Rose Kennedy
Summary: Carboxylic acid derivatives are attractive alternatives to organohalides for cross-coupling electrophiles in fine chemical synthesis. Carboxamides, in particular, have shown promise as versatile electrophiles for nickel-catalyzed coupling reactions. However, the high catalyst loadings and specific substitution patterns required have limited their applications.
Article
Chemistry, Inorganic & Nuclear
Shannon E. E. Cooney, Eric Schreiber, William W. W. Brennessel, Ellen M. M. Matson
Summary: Anionic dopants, such as O-atom vacancies, have a significant impact on the thermochemical and kinetic parameters of proton coupled electron transfer (PCET) at metal oxide surfaces. To gain insights, polyoxovanadate-alkoxide clusters are used as models of reducible metal oxide surfaces. The study shows that the presence of O-atom defects weakens the O-H bond strength and enhances the rate of H-atom uptake due to reduced activation barriers for H-atom transfer at the cluster surface.
INORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Nicole M. B. Cogan, Kevin P. Mcclelland, Chari Y. M. Peter, Chayan Carmenate Rodriguez, Alex A. Fertig, Mitesh Amin, William W. Brennessel, Todd D. Krauss, Ellen M. Matson
Summary: A limitation in the implementation of cadmium chalcogenide quantum dots (QDs) in charge transfer systems is the efficient removal of photogenerated holes. This study shows that incorporating oxygen vacancies into polyoxovanadate-alkoxide clusters can improve hole transfer kinetics and facilitate QD-hole acceptor association through reversible complexation.
Article
Chemistry, Inorganic & Nuclear
Mamta Dagar, D. M. M. Mevan Dissanyake, Daniel N. Kesler, Molly Corr, Joshua D. Mcpherson, William W. Brennessel, James R. Mckone, Ellen M. Matson
Summary: This study demonstrates that the solubility of organic functionalized titanium-substituted polyoxovanadate-alkoxide clusters could be significantly increased in acetonitrile, leading to potential applications in non-aqueous redox flow batteries. The experimental results provide new insights into the impact of structural modifications on the physicochemical properties of these assemblies.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Vinodkumar P. Sajjan, Prabhuodeyara M. Gurubasavaraj, Dhanashree Patil, Vijaykumar Kumbar
Summary: A series of new acylhydrazone derivatives were synthesized and characterized. These compounds showed significant cytotoxic activity against melanoma, colon, and lung cancer cell lines. The compounds were also found to be non-toxic and showed good binding affinity to active pockets of protein inhibitor kinases. These findings suggest that these compounds have potential for the development of new drugs for treating melanoma, colon, and lung cancers.
Article
Chemistry, Multidisciplinary
Medina Afandiyeva, Xijue Wu, William W. Brennessel, Abhishek A. Kadam, C. Rose Kennedy
Summary: This paper describes a novel nickel catalyst and its effective application in the hydroboration of nitriles. By using a tethered NHC-pyridonate ligand, both reagents can be activated simultaneously, enabling efficient catalysis at room temperature.
CHEMICAL COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Parashuram Bannigidad, Namita Potraj, Prabhuodeyara M. Gurubasavaraj, Lakkappa B. Anigol
Summary: The objective of this study is to determine and categorize Boron nanoparticles using digital image processing techniques. Different segmentation techniques are employed to extract spatial features from Transmission Electron Microscope images, and the nanoparticles are categorized based on their size. The results show that the K-means segmentation technique is more effective for Boron nanoparticle image analysis and classification.
JOURNAL OF ADVANCED APPLIED SCIENTIFIC RESEARCH
(2022)