Review
Chemistry, Organic
Roshan I. Patel, Shivani Sharma, Anuj Sharma
Summary: Photoredox chemistry has emerged as an efficient tool in catalyzing organic reactions by utilizing light as an energy source without external initiators or reagents. The cyanide group is crucial in organic chemistry, present in bioactive compounds and pharmaceutical drugs with potential for conversion to other functional groups. Recent advancements in photocatalytic cyanation strategies have shown progress in both homogeneous and heterogeneous photocatalysis.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Zhao Wu, Guangbin Dong
Summary: A strategy for accessing diverse multisubstituted acrylamides from cyclic ketones has been developed using palladium/norbornene catalysis. Key to achieving the desired reactivity and selectivity was the development of bulky C2 secondary amide-substituted norbornene cocatalysts. This method allows for the installation of various moieties at the ipso position and can be used for the synthesis of lactam-containing polycyclic scaffolds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Emilien Le Saux, Eleni Georgiou, Igor A. Dmitriev, Will C. Hartley, Paolo Melchiorre
Summary: A photochemical method for the functionalization of pyridines using radicals derived from allylic C-H bonds is reported. The reaction exhibits distinct positional selectivity and employs a dithiophosphoric acid as a multi-functional catalyst.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Xiaoyu Chen, Yang Geng, Bo Liu, Yu Zhu, Dapeng Zou, Yangjie Wu, Yusheng Wu
Summary: This study reveals a general and efficient photochemical strategy for the synthesis of difluoromethylated dioxodibenzothiazepines and dibenzazepines. The reaction is conducted under mild conditions without using a transition-metal catalyst, offering a green strategy for the synthesis of valuable difluoromethylated seven-membered N-heterocycles.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Zhi Zhang, Liansuo Zu
Summary: The study successfully synthesized a steroid-sterigmatocystin heterodimer using a concise method, including cascade dialdehyde cyclization, phenol-assisted reductive alkylation, and SNAr reaction. The research also explored a glycosylation-inspired method to provide the acetal linkage with ergosterol peroxide.
Article
Chemistry, Organic
Bjoern Siekmeyer, Dennis Luebken, Kevin Bajerke, Bastian Bernhardt, Peter R. Schreiner, Markus Kalesse
Summary: The first bioinspired, enantioselective, and protecting group free total synthesis of the antibacterial sesquiterpenoid (-)-antroalbocin A has been achieved in 12 steps (5.4% overall yield) from dimedone. Computational data indicate that the 1,3-acyl shift benefits from the highly strained 1,3-enone, enabling an increased conversion compared to unstrained substrates. The transformation from 1,3-enone to its bridged isomer is exergonic, further enhancing the conversion efficiency.
Article
Chemistry, Organic
Hao-Cong Li, Guan-Nan Li, Kai Sun, Xiao-Lan Chen, Ming-Xuan Jiang, Ling-Bo Qu, Bing Yu
Summary: A Ce(III)-photocatalyzed method for synthesizing amides from carboxylic acids and aryl isocyanates was developed. The reaction involves the formation of alkyl radicals from carboxylic acids followed by their addition to the electron-deficient carbon.
Article
Chemistry, Organic
Bjoern Siekmeyer, Dennis Luebken, Kevin Bajerke, Bastian Bernhardt, Peter R. Schreiner, Markus Kalesse
Summary: The first bioinspired, enantioselective, and protecting group free total synthesis of the antibacterial sesquiterpenoid (-)-antroalbocin A has been achieved, and the key steps of the synthesis process have been explained.
Article
Chemistry, Organic
Bin Zhao, Gerald B. Hammond, Bo Xu
Summary: The method involves using inexpensive aromatic ketone photocatalysts to synthesize imidazo-isoquinolinone derivatives, tolerating a wide range of functional groups and working well for both alkyl and aryl radicals.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
K. C. Nicolaou, Saiyong Pan, Yogesh Shelke, Dipendu Das, Qiuji Ye, Yong Lu, Susanta Sau, Ruiyang Bao, Stephan Rigol
Summary: A new strategy for the total synthesis of Halichondrin B was described in this study, presenting a novel approach that allows for improved syntheses of complex compounds. The method involves the reversal of sequential construction and the coupling of defined fragments to achieve a convergent pathway.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Kosuke Okada, Ken-ichi Ojima, Hirofumi Ueda, Hidetoshi Tokuyama
Summary: The synthesis of (+)-pleiocarpamine, (+)-voacalgine A and (+)-bipleiophylline was achieved in this study. The 10-step synthesis of (+)-pleiocarpamine features the construction of stereochemistry at the C16 position by radical cyclization and the synthesis of the highly strained cage-like structure via Pd-catalyzed intramolecular aromatic C-H functionalization. By modifying the biomimetic aerobic oxidative coupling of tryptophane derivatives catalyzed by FePc(CO2H)(8), the oxidative coupling of (+)-pleiocarpamine with pyrocatechuic acid produced (+)-voacalgine A. The total synthesis of (+)-bipleiophylline was completed by the second coupling of (+)-voacalgine A with (+)-pleiocarpamine or the one-pot couplings of 2 equiv of (+)-pleiocarpamine with pyrocatechuic acid.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Bo Li, Alessandro Ruffoni, Daniele Leonori
Summary: ortho-Aminophenols are commonly found in many high-value materials and are generally prepared using electrophilic aromatic substitution chemistry. However, this method is not suitable for substrates with a specific arrangement of N- and O-groups. In this study, an alternative strategy using aryl azides as precursors was reported, which utilized low-energy photoexcitation to trigger the decomposition of aryl azides and allowed the introduction of alcoholic nucleophiles into aromatic compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Philip R. D. Murray, James H. Cox, Nicholas D. Chiappini, Casey B. Roos, Elizabeth A. McLoughlin, Benjamin G. Hejna, Suong T. Nguyen, Hunter H. Ripberger, Jacob M. Ganley, Elaine Tsui, Nick Y. Shin, Brian Koronkiewicz, Guanqi Qiu, Robert R. Knowles
Summary: This article presents a comprehensive review of the photochemical and electrochemical applications of multi-site proton-coupled electron transfer (MS-PCET) in organic synthesis. MS-PCET involves the simultaneous exchange of an electron and a proton in a non-classical redox mechanism, offering opportunities for the direct generation of synthetically useful free radical intermediates from common organic functional groups. The article provides an introduction to MS-PCET and a practitioner's guide to reaction design, focusing on the unique energetic and selectivity features of this reaction class. It also discusses various oxidative and reductive PCET activations for bond homolysis and the applications of MS-PCET in asymmetric catalysis, materials, and device applications.
Article
Chemistry, Multidisciplinary
Johannes Grosskopf, Alexandra A. Heidecker, Thorsten Bach
Summary: Racemic 3-substituted oxindoles can be converted into enantiomerically pure or enriched material through photochemical deracemization process. Light energy compensates for the loss of entropy and enables predictable editing of the stereogenic center. The obtained oxindoles are valuable intermediates for further transformations with complete retention at the stereogenic center.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Diego E. Collin, Kristina Kovacic, Mark E. Light, Bruno Linclau
Summary: The article presents a practical procedure for preparing a range of 2-substituted 1,4-cubanedicarboxylic ester derivatives through a radical-mediated chlorocarbonylation process, along with a subsequent regioselective ester hydrolysis to obtain fully differentiated 1,2,4-trisubstituted cubanes.
