Article
Chemistry, Multidisciplinary
Lorenzo V. White, Nan Hu, Yu-Tao He, Martin G. Banwell, Ping Lan
Summary: This study reports an efficient asymmetric chemical synthesis method for (-)-codeine from simple materials, and effective access to pharmacologically valuable derivatives can be obtained through modifications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ya-Kui Sun, Jin-Bao Qiao, Yu-Meng Xin, Qin Zhou, Zhi-Hua Ma, Hui Shao, Yu-Ming Zhao
Summary: In this paper, a concise and divergent synthesis of the complex hasubanan alkaloids metaphanine and oxoepistephamiersine from commercially available and inexpensive cyclohexanedione monoethylene acetal is reported. The synthesis involves a palladium-catalyzed cascade cyclization reaction, regioselective Baeyer-Villiger oxidation followed by a MeNH2 triggered skeletal reorganization cascade, and a strategically late-stage regio-/diastereoselective oxidative annulation of sp(3) C-H bond. Additionally, a highly enantioselective alkylation of cyclohexanedione monoethylene acetal was used for the asymmetric synthesis of the target molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Ya-Kui Sun, Jin-Bao Qiao, Yu-Meng Xin, Qin Zhou, Zhi-Hua Ma, Hui Shao, Yu-Ming Zhao
Summary: A concise and divergent synthesis of the complex hasubanan alkaloids metaphanine and oxoepistephamiersine from commercially available and inexpensive cyclohexanedione monoethylene acetal was reported. The synthesis includes a palladium-catalyzed cascade cyclization reaction, a regioselective Baeyer-Villiger oxidation followed by a MeNH2 triggered skeletal reorganization cascade, and a strategically late-stage regio-/diastereoselective oxidative annulation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Jean-Philippe Fontaine, Vincent Lapointe, Marion Filliatre, Guillaume Belanger
Summary: We present a novel green and metal-free method for the preparation of substituted indolines through photocatalyzed remote alkyl radical generation and cyclization. This method complements existing Fischer indolization, metal-catalyzed couplings, and photocatalyzed radical addition and cyclization. It allows for a wide range of functional groups, including aryl halides, which are incompatible with most existing methods. Electronic bias and substitution were investigated to achieve complete regiocontrol and high chemo-control in indoline formation.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Karli R. Holman, Allison M. Stanko, Matthieu J. R. Richter, Sean S. Feng, Mahideremariyam N. Gessesse, Sarah E. Reisman
Summary: In this study, radical and transition metal-catalyzed cascade cyclization strategies were explored for the synthesis of the tetracyclic core of the augustamine-type Amaryllidaceae alkaloids. The successful synthesis of noraugustamine and the development of an oxidative Heck/aza-Wacker cascade that forms multiple bonds and a quaternary carbon center in a single step were achieved.
Article
Multidisciplinary Sciences
Eleanor M. Landwehr, Meghan A. Baker, Takuya Oguma, Hannah E. Burdge, Takahiro Kawajiri, Ryan A. Shenvi
Summary: Neuroactive metabolites from the bark of Galbulimima belgraveana exhibit varying distributions among trees and are challenging to access through chemical synthesis due to intricate bond networks and dense stereochemistry. However, a new synthetic approach has been developed to reduce the synthetic burden and increase efficiency, allowing for further chemical exploration and biological investigation in Galbulimima alkaloid space.
Article
Chemistry, Physical
Luoting Xin, Wan Wan, Yinghua Yu, Qiuling Wan, Liyao Ma, Xueliang Huang
Summary: The study presents a novel method for the synthesis of pyridoisoquinolinone derivatives using pyridotriazoles and o-bromo/pseudohalo benzaldehydes. This method is efficient and provides a rapid route to prepare protoberberine-type alkaloids. The pyridotriazole plays a dual role in promoting C-H bond functionalization and constructing the polycyclic system through pyridine dearomatization.
Article
Chemistry, Multidisciplinary
Matthew J. J. Genzink, Matthew D. D. Rossler, Herman Recendiz, Tehshik P. P. Yoon
Summary: Chiral acid catalysts are shown to promote highly selective visible-light photocycloadditions, leading to the synthesis of truxinate natural products. This general approach allows for the efficient synthesis of dimeric and pseudodimeric cyclobutane natural products with excellent enantioselectivity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Yoshiki Ono, Keiko Higuchi, Masashi Yamaguchi, Kumi Sugino, Atsuo Nakazaki, Masaatsu Adachi, Toshio Nishikawa
Summary: A new strategy has been developed for the convergent synthesis of the ABCD ring system found in indole terpene alkaloids. This method involves a Sonogashira coupling reaction followed by tandem palladium-catalyzed cyclization, resulting in the formation of the tetracyclic ABCD ring structure. The yield of the desired product is high.
Article
Chemistry, Multidisciplinary
Disni Gunasekera, Jyoti P. Mahajan, Yanick Wanzi, Sachini Rodrigo, Wei Liu, Ting Tan, Long Luo
Summary: Here, a unique electrosynthetic method is reported, which selectively oxidizes tertiary amines to generate alpha-amino radical intermediates instead of iminium cations, providing arylation products. An electrochemical descriptor obtained from cyclic voltammetry studies predicts the optimal alternating current (AC) frequency for various amine substrates, avoiding time-consuming trial-and-error methods for optimizing reaction conditions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Valerie Loesle, Olga Kataeva, Hans-Joachim Knoelker
Summary: The study presents the total synthesis of clausenalansine A, a recently discovered pyrano[3,2-a]carbazole alkaloid, through a synthetic strategy involving key steps such as Buchwald-Hartwig coupling and palladium(II)-catalyzed oxidative cyclization.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Multidisciplinary
Andrew G. Dalling, Georg Spath, Alois Furstner
Summary: This article reports the first total synthesis of a tetracyclic marine pyridinium alkaloid, which was achieved using recent advances in chemoselectivity management. The synthesis involved the formation of critical C-C bond using nickel/iridium photoredox dual catalysis, successful ring closing alkyne metathesis (RCAM) despite the presence of a Lewis acidic alkylidyne catalyst, and a unique iridium catalyzed hydrosilylation reaction. The synthesis also demonstrated site- and chemoselective intramolecular N-alkylation for closing the second strained macrocycle.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Andrew Whyte, Jonathan Bajohr, Ramon Arora, Alexa Torelli, Mark Lautens
Summary: An enantioselective consecutive cyclization/coupling process catalyzed by palladium was reported in this study. The stereoinduction was achieved through an enantioselective carbopalladation, leading to the generation of an intermediate that promotes a nucleopalladation step. This dual cyclization sequence was compatible with various nucleophiles and aryl iodides, producing numerous bisheterocycles in good yields and high regio- and enantioselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Jianhui Qiao, Huili Liu, Shaozhong Wang
Summary: A protocol has been developed for accessing indole-annulated eight- and nine-membered lactams through protonation-induced ring-opening of spiroindolines, with the use of deuterated hydrochloride and deuterated methanol resulting in medium-sized lactam diastereoisomers with a deuterium content ratio around 1:1. The study compared different Bronsted acids and nucleophiles in the transformation process.
Article
Chemistry, Multidisciplinary
Jun Xuan, Paulo A. Machicao, Karl T. Haelsig, Thomas J. Maimone
Summary: This study investigates the differential functionalization of a chemically sensitive bispyrrole framework, leading to the synthesis of multiple bipolamine alkaloids. The findings shed light on their innate chemical reactivity and potential biosynthetic relationships.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Cell Biology
Sanela Vellino, Christiane Oddou, Paul Rivier, Cyril Boyault, Edwige Hiriart-Bryant, Alexandra Kraut, Rene Martin, Yohann Coute, Hans-Joachim Knoelker, Miguel A. Valverde, Corinne Albiges-Rizo, Olivier Destaing
Summary: TRPV4 calcium channel co-localizes with beta 1-integrins at the invadosome periphery and regulates its activation, dependent on its ability to sense ROS. TRPV4 mediates invadosome function through activation of ROS/calcium-sensitive kinase Ask1 and binding with motor protein MYO1C.
JOURNAL OF CELL BIOLOGY
(2021)
Article
Biochemical Research Methods
Michael Witting, Ulrike Schmidt, Hans-Joachim Knoelker
Summary: The study utilized chromatographic and ion mobility separation combined with DIA for lipid analysis in the biomedical model organism Caenorhabditis elegans, showing that this method is effective for initial lipid identification, successfully identifying 45 marado- and lysomaradolipids.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Florian Puls, Philipp Linke, Olga Kataeva, Hans-Joachim Knoelker
Summary: This paper describes a convenient method for the oxidation of olefins to ketones using Fe(dbm)(3) or a combination of iron(II) chloride and neocuproine as catalysts and phenylsilane as an additive. The reactions are efficient and have a high yield and selectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Endocrinology & Metabolism
Alice Aslund, Muhammad Hamza Bokhari, Erika Wetterdal, Rene Martin, Hans-Joachim Knolker, Tore Bengtsson
Summary: Myo1c acts as a PKA repressor and regulates glucose uptake into brown adipose tissue by increasing the expression, translation, and translocation of GLUT1 to the plasma membrane, independent of GLUT4.
MOLECULAR METABOLISM
(2021)
Article
Chemistry, Multidisciplinary
Florian Puls, Felix Seewald, Vadim Grinenko, Hans-Henning Klauss, Hans-Joachim Knoelker
Summary: The study demonstrates the catalytic conversion of olefins to ketones by FePcF16 at room temperature in ethanol under an oxygen atmosphere. By conducting various experiments, the intermediates involved in the oxidation process were identified, leading to a detailed proposed reaction mechanism for the FePcF16-catalyzed Wacker-type oxidation.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Multidisciplinary Sciences
Dumaa Mishig, Margit Gruner, Tilo Luebken, Chunsriimyatav Ganbaatar, Duger Regdel, Hans-Joachim Knoelker
Summary: Seven pyridine alkaloids, a flavonoid acacetin (8), and L-proline anhydride (9) have been isolated from the aerial parts of Caryopteris mongolica Bunge, with compounds 2 and 4-7 being new chemical structures. The structures of the natural products were assigned using MS, IR, 1D NMR, and 2D NMR spectroscopic methods.
SCIENTIFIC REPORTS
(2021)
Article
Cell Biology
Ashish K. Solanki, Manas R. Biswal, Stephen Walterhouse, Rene Martin, Altaf A. Kondkar, Hans-Joachim Knolker, Bushra Rahman, Ehtesham Arif, Shahid Husain, Sandra R. Montezuma, Deepak Nihalani, Glenn Prazere Lobo
Summary: The unconventional myosin MYO1C plays a crucial role in rhodopsin localization to photoreceptor outer segments and is essential for normal visual function. Loss of MYO1C in mice leads to rhodopsin mislocalization, impaired photoreceptor function, and progressively shorter outer segments, indicating its significance in retinal cell physiology.
Article
Chemistry, Multidisciplinary
Alexander Purtsas, Marco Rosenkranz, Evgenia Dmitrieva, Olga Kataeva, Hans-Joachim Knoelker
Summary: In this paper, the oxygenation and amination reactions of tertiary arylamines are described. The key steps of these coupling reactions involve iron-catalyzed oxidative C-O or C-N bond formation, which typically provide the desired products in high yields and with excellent regioselectivity. These transformations are carried out using hexadecafluorophthalocyanine-iron(II) (FePcF16) as catalyst, with the presence of an acid or base additive, and only require ambient air as the oxidant.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Gabriele Theumer, Ingmar Bauer, Anne Jaeger, Lorenz Schwark, Hans-Joachim Knoelker
Summary: This study successfully synthesized seven C-2-alkylcarbazoles using a series of methods, providing analytical standards for identifying them in petroleum samples and source rocks.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Raphael F. Fritsche, Tristan Schuh, Olga Kataeva, Hans-Joachim Knoelker
Summary: We report an iron-catalyzed asymmetric oxidative C-C coupling reaction which takes place at room temperature using air as the final oxidant. By using hexadecafluorophthalocyanine-iron(II) as the catalyst and the presence of catalytic amounts of an axially chiral biarylphosphoric acid, chiral 2,2'-diamino-1,1'-biaryls with up to 90% enantiomeric excess (ee) were obtained as confirmed by chiral HPLC analysis. A detailed mechanism involving a radical cation-chiral phosphate ion pair as the key intermediate leading to the observed asymmetric induction is proposed.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Marie Pascaline Rahelivao, Ingmar Bauer, Tilo Luebken, Olga Kataeva, Anne Vehlow, Nils Cordes, Hans-Joachim Knoelker
Summary: The relative configuration of the marine sesquiterpenoid oxyfungiformin, isolated from the soft coral Capnella fungiformis, was confirmed by synthesis and comparison of values for optical rotation. The cytotoxic activity of oxyfungiformin and a diastereoisomer was observed in lung, breast, and cervical cancer cells.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Tristan Schuh, Olga Kataeva, Hans-Joachim Knoelker
Summary: We report the synthesis and X-ray crystal structure of mu-oxo-bis[(octacosafluoro-meso-tetraphenylporphyrinato)iron(iii)] [(FeTPPF28)(2)O]. This novel iron complex acts as an efficient catalyst for oxidative biaryl coupling reactions of diarylamines and carbazoles. The asymmetric oxidative coupling, in the presence of an axially chiral biaryl phosphoric acid as co-catalyst, provides 2,2'-bis(arylamino)-1,1'-biaryls with 96% ee. Additionally, the Wacker-type oxidation of alkenes to ketones with (FeTPPF28)(2)O as catalyst and phenylsilane as reductant proceeds at room temperature with air as the terminal oxidant, resulting in increased ketone/alcohol product ratios for internal and aliphatic alkenes.
Article
Biochemistry & Molecular Biology
Ana P. Gomez-Escribano, Carlos Mora-Martinez, Marta Roca, Denise S. Walker, Joaquin Panadero, Maria D. Sequedo, Ratni Saini, Hans-Joachim Knoelker, Jose Blanca, Juan Burguera, Agustin Lahoz, Joaquin Canizares, Jose M. Millan, Nick O. Burton, William R. Schafer, Rafael P. Vazquez-Manrique
Summary: Alzheimer's, Parkinson's and Huntington's diseases are caused by mutations that enhance protein aggregation. However, our understanding of the molecular mechanisms involved in these pathways is still limited, hindering the development of effective treatments. In this study, we investigated the protective mechanisms against dysregulated homeostasis by screening for mutations that enhance aggregation in Caenorhabditis elegans. We found that the stomatin homologue UNC-1 activates neurohormonal signalling to modulate protein homeostasis.
Meeting Abstract
Ophthalmology
Glenn Prazere Lobo, Rakesh Radhakrishnan, Venkateshwara Dronamraju, Grace Song, Heidi Roehrich, Vladimir Tsuprun, Rene Martin, Sebahattin Cureoglu, Hans-Joachim Knolker, Erik J. Van Kuijk, Robert B. Hufnagel, Sandra R. Montezuma, Rafael da Costa Monsanto
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)
Article
Chemistry, Organic
Valerie Loesle, Olga Kataeva, Hans-Joachim Knoelker
Summary: The study presents the total synthesis of clausenalansine A, a recently discovered pyrano[3,2-a]carbazole alkaloid, through a synthetic strategy involving key steps such as Buchwald-Hartwig coupling and palladium(II)-catalyzed oxidative cyclization.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Organic
Fuying Zhu, Yamei Lin
Summary: In this study, a low-metal iron-supported catalyst (Fe20/NC-Mg) was reported for the efficient synthesis of quinoxaline compounds, using water as a solvent and without additional bases. The synergistic effect of FeNx site and Mg (OH)2 nanorods in the catalyst played a key role in achieving high yields (82-91%) in 16 examples. The gram-level synthesis and reusability of the catalysts after four cycles demonstrated its industrial application potential.
Article
Chemistry, Organic
Mikhail Kozlov, Alexey Tyurin, Andrey Dmitrenok, Vyacheslav Rusak, Aleksander Fedorov, Igor Zavarzin, Yulia Volkova
Summary: This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.
Article
Chemistry, Organic
Jisna Jose, Thomas Mathew
Summary: 2-Cyclopentenone and its derivatives are highly esteemed synthetic intermediates with exceptional utility in organic synthesis. They are favored structural motifs in numerous pharmaceutical drugs and natural products, highlighting their significance. The review discusses the various methods used to synthesize cyclopentenones from 2016 to 2023.
