1-4-Alkynediols serve as readily available starting materials for isomerisation to 1,4-diketones, which can be converted in situ into the corresponding furans by acid-catalysed dehydration. A range of 2,5-disubstituted furans was prepared using the ruthenium-based catalyst Ru(PPh3)(3)(CO)H-2 with Xantphos at 1 mol % loading. (C) 2007 Published by Elsevier Ltd.
Copper-Catalyzed Decarboxylative Oxyalkylation of Alkynyl Carboxylic Acids: Synthesis of γ-Diketones and γ-Ketonitriles
作者:Yi Li、Jia-Qi Shang、Xiang-Xiang Wang、Wen-Jin Xia、Tao Yang、Yangchun Xin、Ya-Min Li
DOI:10.1021/acs.orglett.9b00520
日期:2019.4.5
A novel copper-catalyzed decarboxylative oxyalkylation of alkynyl carboxylic acids with ketones and alkylnitriles via direct C(sp3)–H bond functionalization to construct new C–C bonds and C–O double bonds was developed. This transformation is featured by wide functionalgroup compatibility and the use of readily available reagents, thus affording a general approach to γ-diketones and γ-ketonitriles
inversion of the normal reactivity (umpolung) of aldehydes has been induced via N-heterocycliccarbenes (NHCs) thiazol-2-ylidenes 2a or 3a, generated by simple electrolyses of solutions containing thiazolium salt 2 or 3. Accordingly, 1,4-dicarbonyl compounds have been obtained, in mild conditions and in moderate to very high yields, via 1,4-addition of the Breslowintermediates to the suitable Michael
Development of a Palladium-Catalyzed Carbonylative Coupling Strategy to 1,4-Diketones
作者:Hongfei Yin、Dennis U. Nielsen、Mette K. Johansen、Anders T. Lindhardt、Troels Skrydstrup
DOI:10.1021/acscatal.6b00733
日期:2016.5.6
We report on a three-componentpalladium-catalyzed coupling strategy for accessing a wide range of 1,4-diketones, which represent important precursors to heterocycles. Our method relies on a carbonylative Heck reaction employing substituted allylic alcohols, aryl iodides, and carbon monoxide. The reaction conditions are mild and do not require high CO pressure, and a wide functional group tolerance
Silver-Catalyzed Controlled Intermolecular Cross-Coupling of Silyl Enol Ethers: Scalable Access to 1,4-Diketones
作者:Li Xu、Xiaoyi Liu、Gregory R. Alvey、Andrey Shatskiy、Jian-Quan Liu、Markus D. Kärkäs、Xiang-Shan Wang
DOI:10.1021/acs.orglett.2c01477
日期:2022.7.1
A protocol for silver-catalyzed controlled intermolecular cross-coupling of silyl enolates is disclosed. The protocol displays good functional group tolerance and allows efficient preparation of a series of synthetically useful 1,4-diketones. Preliminary mechanistic investigations suggest that the reaction proceeds through a one-electron process involving free radical species in which PhBr acts as