Article
Chemistry, Multidisciplinary
David Egea-Arrebola, F. Wieland Goetzke, Stephen P. Fletcher
Summary: Rhodium-catalyzed enantioselective additions of aryl and vinyl boronic acids to cyclobutenone ketals are described in this work. The reaction involves enantioselective carbometalation to give cyclobutyl-rhodium intermediates, followed by beta-oxygen elimination to afford enantioenriched enol ethers. Overall, this addition serves as a surrogate for Rh-catalyzed 1,4-additions to cyclobutenone.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Federica Carlet, Greta Bertarini, Gianluigi Broggini, Alexandre Pradal, Giovanni Poli
Summary: A new C(sp(3))-H functionalization reaction has been developed, allowing for the oxidative alpha-allylation of allyl- and benzyl- methyl ethers under mild conditions using cheap and green oxoammonium salts. The reaction scope was studied over 27 examples, considering the substituents on the two coupling partners.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Nansalmaa Otog, Hayato Inoue, Doan Thi Thuy Trinh, Zolzaya Batgerel, Niklas Maximilian Langendorf, Ikuhide Fujisawa, Seiji Iwasa
Summary: The stereoselective synthesis of optically active cyclopropylsilanes was achieved in excellent yields and diastereo- and enantioselectivities with Ru(II)-Pheox catalysts. Among these catalysts, p-MeO-Ru(II)-Pheox was found to be the best for cyclopropanation reactions. The derivatives of cyclopropylsilanes could be transformed into beneficial building blocks for the synthesis of bioactive compounds.
Article
Chemistry, Physical
Yeong Bum Kim, Dongwook Kim, Shashikant U. Dighe, Sukbok Chang, Jung-Woo Park
Summary: This research describes a novel cobalt-catalyzed reaction for the synthesis of terminal branched allylsilanes under mild conditions. Mechanistic studies show the key intermediate and the order of bond migration involved in the process.
Article
Chemistry, Applied
Elisabeth L. R. Leonard, Geoffrey R. Akien, Thomas K. Britten, Nahin Kazi, Dean D. Roberts, Mark G. Mclaughlin
Summary: A rapid method for synthesizing functionalized allylsilanes from easily available vinylsilanes was presented. The key step involved Bronsted acid catalyzed dehydration, resulting in good yields (22-98%) of allylsilanes, mostly as a single geometric isomer. Additionally, a possible allylation-Cope pathway was discovered for certain substrates and attempts to optimize it were described.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Biochemistry & Molecular Biology
Melvyn B. Ansell, George E. Kostakis, Oscar Navarro, John Spencer
Summary: The stoichiometric reaction of cis-[Pd(ITMe)(2)(SiR3)(2)] with allyl bromide leads to the corresponding allylsilanes and complexes of the type trans-[Pd(ITMe)(2)(SiR3)(Br)]. The structure of trans-[Pd(ITMe)(2)(SiMe2Ph)Br] 2b, determined in solid state, exhibits a slightly distorted square-planar geometry with N-heterocyclic carbene ligands in a trans-configuration.
Article
Chemistry, Organic
Sravan K. Jonnalagadda, Bader Huwaimel, Shirisha Jonnalagadda, Jered C. Garrison, Paul C. Trippier
Summary: In this study, the synthesis of highly strained fused substituted dihydrobenzopyran cyclopropyl lactones derived from coumarin carboxylates was reported. The substrate scope was found to tolerate a variety of 6- and 8-substituents on the coumarin ring. However, substitution at the 5- or 7-position was resistant to tricyclic lactone formation, except when 7-methyl substitution was present. A plausible mechanism involving intramolecular rearrangement of trans cyclopropyl methyl ketones with phenolic acetate to form a hemiacetal was proposed for the formation of the fused lactone.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Jiabao Tian, Lei Zhou
Summary: This study describes a photocatalytic C-H gem-difunctionalization of 1,3-benzodioxoles with two different alkenes for the synthesis of highly functionalized monofluorocyclohexenes. By using 4CzIPN as the photocatalyst, the direct single electron oxidation of 1,3-benzodioxoles enables their defluorinative coupling with alpha-trifluoromethyl alkenes to produce gem-difluoroalkenes. The C-H bond of the resulting gamma,gamma-difluoroallylated 1,3-benzodioxoles can be further functionalized via radical addition to electron-deficient alkenes using a more oxidizing iridium photocatalyst, leading to the formation of monofluorocyclohexenes through carbanion capture and beta-fluoride elimination.
Article
Chemistry, Organic
Christopher R. Myers, Paul Spaltenstein, Lauren K. Baker, Cody L. Schwans, Timothy B. Clark, Gregory W. O'Neil
Summary: In this study, products from an iodine-mediated diallylsilane rearrangement underwent an asymmetric dihydroxylation reaction to form diastereomeric 6-membered oxasilacycles. Removal of the epimeric stereocenter among the diastereomeric mixture by elimination of iodine resulted in a single enantioenriched cyclic allyl silyl ether. The resulting allyl silane was then successfully utilized in several further transformations, offering an alternative approach for preparing useful polyoxygenated intermediates for enantioselective synthesis.
TETRAHEDRON LETTERS
(2021)
Article
Biochemistry & Molecular Biology
Zubao Gan, Deyun Cui, Hongyun Zhang, Ying Feng, Liying Huang, Yingying Gui, Lu Gao, Zhenlei Song
Summary: The Hosomi-Sakurai allylation of allylsilanes with beta,gamma-unsaturated alpha-ketoesters has been successfully catalyzed by (Ph3C)[BPh((F))(4)] to afford gamma,gamma-disubstituted alpha-ketoesters in high yields and excellent chemoselectivity. Preliminary mechanistic studies indicate that the trityl cation is the major contributor to the catalysis, with the silyl cation playing a minor role.
Article
Chemistry, Organic
Huaxin Zhang, Yongge Xiong, Mu-Jia Luo, Ruchun Yang, Jiang Bai, Xian-Rong Song, Qiang Xiao
Summary: Here, a novel and sustainable electrochemically driven oxidative 5-exo-dig radical cyclization of N-propargylbenzamides with alcohols is described, providing a convenient method for the synthesis of structurally diverse oxazole ketals in moderate to good yields. This protocol is achieved under mild conditions in an undivided cell without the need for external transition-metal catalysts, chemical oxidants, and ketalization acids, and exhibits scalability, broad substrate scope, and excellent functional group compatibility. Mechanistic studies reveal that the reaction proceeds via a nucleophilic substitution process rather than ketalization.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Yaxin Zeng, Hui Yang, Jiayi Du, Qin Huang, Guoliang Huang, Ying Xia
Summary: The control of linear/branched selectivity in transition-metal catalyzed allyl-allyl cross-coupling reactions has been investigated in this study. It has been found that the terminal/internal regioselectivity can be switched by fine-tuning the rhodium catalytic system. Different types of 1,5-dienes are produced with good yields, exhibiting isomerized terminal, internal, and terminal regioselectivity.
Article
Chemistry, Physical
Lu Chen, Zhenyuan Lin, Zilong Zhang, Xiaoyan Bai, Huahui Wang, Ya Li, Hao Lu, Wei Yang, Huanying Li, Yibiao Li
Summary: Carbonyl compounds are crucial in organic synthesis due to their versatile reactivities, but current transformations have limitations. Developing a novel MOFsTiO2 photocatalyst for converting carbonyl compounds to acetals/ketals is critical. This strategy demonstrates efficient acetalisations of carbonyl compounds, providing access to a wide variety of compounds with excellent yields and broad substrate scope, making it applicable in green catalytic systems.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Daniel Sowa Prendes, Florian Papp, Nagesh Sankaran, Nardana Sivendran, Frederike Beyer, Christian Merten, Lukas J. Goossen
Summary: Arylglycines, which are important pharmacophores in several top-selling drugs, can now be synthesized from abundant aryl chlorides using a Pd-catalyzed Schollkopf-type amino acid synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Chun-Wei Chang, Mei-Huei Lin, Chieh-Kai Chan, Kuan-Yu Su, Chia-Hui Wu, Wei-Chih Lo, Sarah Lam, Yu-Ting Cheng, Pin-Hsuan Liao, Chi-Huey Wong, Cheng-Chung Wang
Summary: The acceptor nucleophilic constants (Aka) database quantifies the nucleophilicity of hydroxyl groups in glycosylation reactions, accurately predicting stereoselectivity and yield.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(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.