Article
Chemistry, Organic
Ke Yu, Qianjin Chen, Weiping Liu
Summary: An atom-economical and straightforward methodology for the synthesis of quinolines from alpha-2-aminoaryl alcohols and secondary alcohols is described. This protocol uses an Earth-abundant and air-stable iron catalyst under activating agent-free conditions, resulting in high yields and good functional group tolerance. Notably, the method allows for the synthesis of highly substituted fused polycyclic quinolines using secondary alpha-2-aminoaryl alcohols and beta-substituted secondary alcohols, achieving up to 94% isolated yields.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Physical
Dipanjan Bhattacharyya, Priyanka Adhikari, Kritartha Deori, Animesh Das
Summary: The synthesis of N-heterocycles is important in pharmaceuticals, materials science, and natural product synthesis. This study presents an efficient method for the synthesis of quinoline and quinazoline derivatives through an alcohol-catalyzed acceptorless dehydrogenative coupling (ADC). The use of a bifunctional ruthenium NNN-pincer complex as the catalyst allows the synthesis of a wide range of substituted quinolines and quinazolines with high yields and selectivity.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Organic
Suvam Paul, Sourav Das, Tathagata Choudhuri, Papiya Sikdar, Avik Kumar Bagdi
Summary: A visible-light-induced cross-dehydrogenative methodology has been developed for the regioselective sulfenylation of pyrazolo[1,5-a]pyrimidine derivatives. Rose bengal, blue LEDs, KI, K2S2O8, and DMSO are all essential for this photocatalytic transformation. The protocol is applicable for the synthesis of a library of 3-(aryl/heteroaryl thio)pyrazolo[1,5-a]pyrimidine derivatives with broad functionalities. The selectivity and scalability of the methodology have been also demonstrated. Moreover, the efficiency of this strategy for sulfenylation of pyrazoles, indole, imidazoheterocycles, and 4-hydroxy coumarin has been proven. The mechanistic investigation revealed the radical-based mechanism and formation of diaryl disulfide as a key intermediate for this cross-dehydrogenative coupling reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Suvam Paul, Sourav Das, Tathagata Choudhuri, Papiya Sikdar, Avik Kumar Bagdi
Summary: A visible light-induced cross-dehydrogenative methodology has been developed for the regioselective sulfenylation of pyrazolo[1,5-a]pyrimidine derivatives. This protocol allows the synthesis of a library of 3-(aryl/heteroaryl thio)pyrazolo[1,5-a]pyrimidine derivatives with broad functionalities. The methodology also shows selectivity, scalability, and efficiency in sulfenylation of various substrates.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Meng-Meng Liu, Yankun Xu, Chuan He
Summary: In this study, a highly enantioselective synthesis of silicon-stereogenic silazanes was achieved through catalytic dehydrogenative coupling of dihydrosilanes with anilines. The reaction synthesized various chiral silazanes and bis-silazanes with excellent yields and stereoselectivities (up to 99% ee). Further applications included the construction of polycarbosilazanes with configurational main chain silicon-stereogenic chirality, and the transformation of the enantioenriched silazanes into various chiral silane compounds, demonstrating their potential utilities as synthons for novel silicon-containing functional molecules.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Pei Fan, Yujia Mao, Chuan Wang
Summary: Herein, we report a palladium/TBADT-cocatalyzed dehydrogenative cross-coupling reaction that enables the synthesis of various 1,4-diketones from simple allylic alcohols and aldehydes as precursors under mild reaction conditions.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Chen Su, Wen-Hua Xu, Rui-Li Guo, Xing-Long Zhang, Xue-Qing Zhu, Ya-Ru Gao, Yong-Qiang Wang
Summary: This study developed a novel method for the synthesis of aporphine analogues, utilizing an intramolecular dehydrogenative coupling of two inert aryl C-H bonds. The method not only exhibits high compatibility with various functional groups, but has also been further applied for the synthesis of natural products aporphine and zenkerine.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yaoyu Liang, Jie Luo, David Milstein
Summary: In this study, a new reaction of acceptorless dehydrogenative coupling of epoxides and amines to form amides catalyzed by ruthenium pincer complexes is reported. This reaction shows high yield and selectivity, and is significant in various academic and industrial fields.
Article
Chemistry, Physical
Shivangi Gupta, Ankur Maji, Dibyajyoti Panja, Mita Halder, Sabuj Kundu
Summary: Efficient synthesis of quinolines, pyridines, and pyrroles via alcohol dehydrogenative coupling strategy using copper oxide nanoparticles as catalyst is reported. Various functionalized quinolines, pyridines, and pyrroles were efficiently synthesized from different amino alcohols and a diverse range of ketones. Control experiments were conducted to elucidate the mechanism. The catalyst showed no significant loss in catalytic activity after being recycled up to 6 runs.
JOURNAL OF CATALYSIS
(2022)
Review
Chemistry, Multidisciplinary
Baitan Chakraborty, Christine K. Luscombe
Summary: Due to their versatile (opto)electronic properties, conjugated polymers have been widely used in organic electronic devices. Various cross-coupling reactions, such as Stille, Suzuki, Kumada couplings, and direct arylation reactions, have been effective for synthesizing conjugated polymers. Recent interest in donor-acceptor polymers has led to the development of cross-dehydrogenative coupling (CDC) polymerization, which allows the synthesis of alternating copolymers without prefunctionalization of monomers. This article discusses the development of CDC polymerization protocols and provides insights from small molecule CDC reactions for a better understanding of these reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Xiaoyu Zhang, Yujie Zhang, Jiaqiao Ding, Liusheng Wang, Weihua Chen, Xinyan Li, Bing Cui, Mingqin Zhao, Zhihui Shao
Summary: This study presents an efficient and green method for synthesizing thiophene-substituted ketones from 2-thiophenemethanol and ketones via dehydrogenative coupling using manganese complexes as catalysts. The strategy demonstrated a broad applicability and expanded the range of usable substrates, leading to the successful synthesis of a series of thiophene-substituted saturated ketones and alpha, beta-unsaturated ketones in good yields.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Physical
Zhongyi Zeng, Jonas F. Goebel, Xianming Liu, Lukas J. Goossen
Summary: 2,2'-Biaryldicarboxylates can be conveniently accessed from benzoic acids via Rh-catalyzed electrooxidative C-H/C-H couplings, yielding valuable dihydrogen as a byproduct. RhCl3 center dot 3H(2)O catalyzes the oxidative carboxylate-directed ortho-homocoupling of various aromatic acids in an undivided cell with Pt electrodes, with a current efficiency of 67%.
Article
Chemistry, Multidisciplinary
Rongxiang Chen, Bing Liu, Wenbo Li, Kai-Kai Wang, Changqing Miao, Zhizhuang Li, Yingjie Lv, Lantao Liu
Summary: This methodology describes a PIDA-promoted cross-dehydrogenative coupling reaction between N-hydroxyphthalimide (NHPI) and aryl ketones for efficient synthesis of N-alkoxyphthalimide products in moderate to good yields, which is characterized by catalyst-free conditions, readily available starting materials, wide substrate scope, and operational simplicity. Additionally, a gram-scale reaction and synthetic transformation of the product into synthetically useful intermediates have been demonstrated.
Review
Chemistry, Multidisciplinary
Souvik Majumder, Sumit Ghosh, Pranjal Pyne, Anogh Ghosh, Debashis Ghosh, Alakananda Hajra
Summary: This article provides an overview of recent research and developments in the synthesis of unsymmetrical biheteroarenes via dehydrogenative and decarboxylative couplings, focusing on literature primarily from 2011 to 2021. The content is subdivided based on the catalysts used in the reactions to simplify understanding for readers.
Article
Chemistry, Physical
Zhe Wu, Zhi-Qin Wang, Hua Cheng, Zhong-Hui Zheng, Ye Yuan, Cheng Chen, Francis Verpoort
Summary: This study developed a series of cyclometallated N-heterocyclic carbene-Ru (NHC-Ru) complexes for efficient synthesis of carboxylic acids at low Ru loading. The effects of ligand tuning and other parameters on the catalytic process were thoroughly studied. The results demonstrated the superiority of this method compared to previous literature reports.
APPLIED CATALYSIS A-GENERAL
(2022)
Article
Chemistry, Multidisciplinary
Rajarshi Mondal, Robert J. Ortiz, Jason D. Braun, David E. Herbert
Summary: A new N-heterocyclic carbene ligand precursor containing a pi-extended phenanthridine unit was presented. The precursor can be installed on silver centers and used in a transmetalation reaction to generate a Pd(II) coordination complex for catalyzing the synthesis of Piribedil.
CANADIAN JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Organic
Issiah B. Lozada, Robert J. Ortiz, Jason D. Braun, J. A. Gareth Williams, David E. Herbert
Summary: A series of intramolecular, donor-stabilized BF2 complexes supported by phenanthridinyl-decorated, beta-ketoiminate chelating ligand scaffolds were characterized by spectroscopy and X-ray diffraction. The orientation of the phenanthridinyl arm in solution is fixed, despite not coordinating to the boron center, and a through-space interaction between phenanthridinyl C-H and a single fluorine atom was observed. Methylation of the phenanthridinyl nitrogen restricts rotation, leading to stronger emission in solution.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Christopher B. Larsen, Jason D. Braun, Issiah B. Lozada, Kristjan Kunnus, Elisa Biasin, Charles Kolodziej, Clemens Burda, Amy A. Cordones, Kelly J. Gaffney, David E. Herbert
Summary: Accessing panchromatic absorption and long-lived charge-transfer (CT) excited states is crucial for developing abundant-metal molecular photosensitizers. This study presents an aerobically stable Fe(II) complex with panchromatic absorption and a 3 ns excited-state lifetime, demonstrating the importance of metal-ligand covalency in elongating excited state lifetimes. The findings highlight a novel design principle for extending excited state lifetimes in abundant metal photosensitizers.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Inorganic & Nuclear
Issiah B. Lozada, J. A. Gareth Williams, David E. Herbert
Summary: A series of platinum (II) complexes of benzannulated pincer-type diarylamido ligands were synthesized and characterized, showing strong metal-to-ligand charge-transfer absorptions and phosphorescence at room temperature. Computational modeling revealed efficient population of the lowest-lying triplet state in these complexes. The optical properties were minimally affected by substituents in the phenanthridinyl unit, but emission was significantly quenched by molecular distortions in the excited state.
INORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Inorganic & Nuclear
Dion B. Nemez, Issiah B. Lozada, Jason D. Braun, J. A. Gareth Williams, David E. Herbert
Summary: This study presents the synthesis, characterization, and coordination chemistry of a doubly pi-extended bipyridine analogue, 6,6'-biphenanthridine (biphe), as well as the emission properties of its coordination complexes in the excited state.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Issiah B. Lozada, Jason D. Braun, J. A. Gareth Williams, David E. Herbert
Summary: This study presents a series of unique Zn(II) complexes with a pseudo-octahedral structure. By incorporating phenanthridine units into the ligands, these complexes exhibit extended luminescence lifetimes in the solid state. The research also indicates the role of aggregation in enhancing emission in solid state.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
David E. Herbert
Summary: The C-N bond is crucial for the properties and reactivity of coordination complexes. This paper presents an overview of our work investigating the impact of site-selective benzannulation on the chemistry and properties of phenanthridine as a molecule and ligand.
CANADIAN JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Dion B. Nemez, Baldeep K. Sidhu, Kevin Carlin, Albert Friesen, David E. Herbert
Summary: The synthesis of novel analogues of the antimalarial (hydroxy)chloroquine was achieved through the substitution of the chloro group at the 4-position of 4,7-dichloroquinolines with amino alcohols. Short-chain and long-chain coupling partners were used, with electron-donating amino and dimethylamino substituents being tolerated. The compounds were characterized using various techniques and crystal structures of selected products were obtained.
CANADIAN JOURNAL OF CHEMISTRY
(2023)
News Item
Chemistry, Multidisciplinary
Robert J. Ortiz, David E. Herbert
Summary: Charge-transfer emission, which is rare for iron coordination complexes, has been observed in an Fe(iii) complex. The emission arises from both metal-to-ligand and ligand-to-metal charge transfer.
Article
Chemistry, Inorganic & Nuclear
Robert J. Ortiz, Michael Shepit, Johan van Lierop, J. Krzystek, Joshua Telser, David E. Herbert
Summary: The ligand fields of Ni(II) complexes supported by diarylamido pincer-type amido ligands were investigated. The ligand field parameters were determined using HFEPR, SQUID magnetometry, and electronic absorption spectroscopy. The ability to electrochemically address ligand-based oxidations and the presence of electronic communication between N-amido moieties were also studied.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Issiah B. Lozada, Daniel Gussakovsky, Amarasooriya M. D. S. Jayawardhana, Sean A. Mckenna, Yao-Rong Zheng, David E. Herbert
Summary: This article reports the non-specific interactions between Pt(II) complexes supported by chelating, multidentate ligands and DNA. It is shown that CF3LPtCl exhibits turn-on luminescence through intercalation-mediated mechanism in O2-saturated aqueous buffer. Visible light irradiation significantly enhances its activity, leading to increased photocytotoxicity against a variety of human cancer cell lines. Mechanistic studies reveal improved cellular uptake of CF3LPtCl compared with cisplatin, with localization in the nucleus and mitochondria triggering effective apoptosis. Photosensitization experiments demonstrate that CF3LPtCl efficiently generates singlet dioxygen (1O2), suggesting its potential in photodynamic therapy.
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
(2023)
