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The present work focuses on a comprehensive density functional theory (DFT) study of newly discovered base-catalyzed substrate-controlled dimerizations of aliphatic alkynones. In order to understand the origin of selectivity of the cascade assemblies of 6-methylene-5-oxaspiro[2.4]heptanones and 2-alkenylfurans, structural and electronic properties of neutral and deprotonated alkynone molecules, thermodynamic and kinetic characteristics of the deprotonation of alkynones having diverse C-H active substituents at the carbonyl function under the action of a base, and thermodynamic and kinetic characteristics of possible mechanisms of the discussed cascade reactions were theoretically assessed. The obtained computational results have confirmed and clarified an early qualitative assumption on the key role of the nature of the aliphatic substituent. Apart from fully rationalizing the experimental results, the theoretical DFT data give valuable details and data for predicting the outcome of related base-catalyzed reactions between various electrophilic substrates and nucleophilic species formed from C-H active aliphatic alkynones.
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http://dx.doi.org/10.1021/acs.joc.3c01106 | DOI Listing |
Org Lett
December 2024
Leibniz-Institut für Katalyse e.V., Albert-Einstein-Straße 29a, 18059 Rostock, Germany.
Herein, we developed a mild and efficient palladium-catalyzed carbonylative Sonogashira coupling of aryl thianthrenium salts with aliphatic alkynes and benzyl acetylene toward alkynones and furanones. Various desired products were prepared in good yields with broad functional group tolerance including the bromide group. In the case of using benzyl acetylene, the corresponding furanones can be obtained in good yields under the same conditions with two molecules of CO inserted.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2023
Henan University of Technology, 100 Lianhua Street, Zhongyuan District, Zhengzhou, 450001, China.
Site-specific modification of thiol-containing biomolecules has been recognized as a versatile and powerful strategy for probing our biological systems and discovering novel therapeutics. The addition of lipophilic silicon moiety opens up new avenues for multi-disciplinary research with broad applications in both the medicinal and material sciences. However, adhering to the strict biocompatibility requirements, and achieving the introduction of labile silicon handle and high chemo-selectivity have been formidable.
View Article and Find Full Text PDFJ Org Chem
August 2023
A.E. Favorsky Irkutsk Institute of Chemistry SB RAS, 1 Favorsky St, Irkutsk 664033, Russian Federation.
The present work focuses on a comprehensive density functional theory (DFT) study of newly discovered base-catalyzed substrate-controlled dimerizations of aliphatic alkynones. In order to understand the origin of selectivity of the cascade assemblies of 6-methylene-5-oxaspiro[2.4]heptanones and 2-alkenylfurans, structural and electronic properties of neutral and deprotonated alkynone molecules, thermodynamic and kinetic characteristics of the deprotonation of alkynones having diverse C-H active substituents at the carbonyl function under the action of a base, and thermodynamic and kinetic characteristics of possible mechanisms of the discussed cascade reactions were theoretically assessed.
View Article and Find Full Text PDFChemistry
March 2018
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China.
Asymmetric cascade double Michael additions to construct 2'-substituted 3,3'-spirooxindoles by using a chiral guanidine organocatalyst has been developed. A series of spirooxindole derivatives containing dihydrofuran or pyrrolidine subunits were obtained with good to excellent diastereo- and enantioselectivities. The method showed great tolerance of a number of aromatic and aliphatic alkynones.
View Article and Find Full Text PDFChemistry
December 2012
Department of Chemistry, Zhejiang Sci-Tech University, Xiasha Campus, Hangzhou, Zhejiang Province, 310018, PR China.
A general and efficient method for the palladium-catalyzed carbonylative coupling of aryl iodides to benzyl acetylenes has been developed. Various furanones have been prepared in excellent yields from their corresponding benzyl acetylenes at room temperature under a CO atmosphere. For aliphatic alkynes, their corresponding alkynones were obtained in good yields.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!