Microwave-assisted solid-phase Dötz benzannulation reaction: a facile synthesis of 2,3-disubstituted-1,4-naphthoquinones (original) (raw)
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Synthesis of 1,4-naphthoquinones derivatives under non-conventional conditions and in silico studies
Proceedings of 6th International Electronic Conference on Medicinal Chemistry, 2020
Microwave irradiation synthesis were completed within ≤ 10 min, whereas similar reactions under conventional heating at reflux gave lower or similar yields, with comparatively longer reaction times. For arylamines derivatives (4a-d and 5a-d) yields were significantly higher for 1,4-NQ derivatives (4a-d), due to the presence of CaCO 3. For alkylamines derivatives (4e-g and 5e-g) similar results were obtained with both precursors. Compounds were obtained by one-step Michael addition to C2 of nuclear naphthoquinone structure. Structural characterization were assigned based on their 1 H and 13 C NMR spectra and two-dimensional NMR (HSQC and HMBC) techniques. ESI-Mass spectrometry was used to corroborate NMR data and all compounds exhibited the expected m/z signals correspondent to the protonated molecules [M+H] + .
Tetrahedron, 2013
The palladium-catalyzed SuzukieMiyaura coupling reaction of tetrabromo-p-benzoquinone and 2,3dibromonaphthoquinone provide a convenient approach to tetraaryl-p-benzoquinones and 2,3diarylnaphthoquinones. SuzukieMiyaura of tetrabromo-1,4-phenylene bis(trifluoromethanesulfonate) and of 2,3-dibromonaphthalene-1,4-diyl bis(trifluoromethanesulfonate) resulted in the formation of the same type of quinone products instead of the expected benzene and naphthalene derivatives.
Synthesis and Study of Naphthoquinones Derivatives
Applied Mechanics and Materials, 2016
In this research, we reported the study and synthesis of naphthoquinones intermediate compounds lead to the target naphthoquinones derivatives product. Naphthoquinones derivatives have long been known to display anticancer and antimalarial activity in addition to a wide variety of other bioactivities. Moreover, it has been reported to possess antimalarial disease against Plasmodium falciparum. The naphthoquinones derivatives product (5) were synthesized by coupling with 2-(3-bromo-2,2-dimethylpropyl)-1-methoxynaphthalene (4) and methyl ketone fatty acid (3). The 2-(3-bromo-2,2-dimethylpropyl)-1-methoxynaphthalene (4) was constructed by 1-hydroxy-2-naphthoic acid (1) in 5 steps with good to excellent yield. The synthetic pathway was started with the methylation provided the methyl ester naphthoquinones compound in 93% yields. Then, the reduction of methyl ketone by using LiAlH4 gave the alcohol compound in 90% yields. Methyl alcohol was changed to the alkyl bromide using PBr3 in 75% ...
Acetylenic condensation of 2-N,N-dialkylamino- and 2-alkoxy-3-bromo-1,4-naphthoquinones
Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1985
Substitution of halogen on aromatic rings by acetylenic groups under conditions of copper and palladium complex catalysis is a general method of synthesis of carbo-and heteroaromatic acetylenic compounds [i]. In acetylenic condensations the acid chlorides of carboxylic acids [2] and some vinyl bromide substituents were also introduced [3]. Unlike aroma-C2oHisNO2
2017
The synthesis of quinazolinones using a microwave method and their functionalization with the Mitsunobu reaction were investigated. The microwave method was proven to be rapid, simple and efficient in the synthesis of the starting quinazolinone. The results show an increase of obtained yields when compared with the conventional thermal method and the formation of the final derivatives in one step reaction without the activation of the alcohol function. The title quinazolinones were functionalized with a variety of variously substituted phenols using the Mitsunobu reaction to produce the corresponding new ether bridged derivatives in a 57-87% yield.
1,4-Naphthoquinones have been known to possess a wide spectrum of biological activities such as antidiabetic, antibacterial, antimalarial, anticancer and antifungal activities. An efficient, environmentally friendly two step process for synthesizing various 2-substituted 1,4naphthoquinones is described, starting from 2-bromonaphthalene and olefinic substrates using the Heck reaction in an ionic liquid (IL) followed by oxidation. It provides for a rapid and "green" methodology for the synthesis of the biologically active 2-substituted 1,4naphthoquinones.
A Decade with Dötz Benzannulation in the Synthesis of Natural Products
Synlett, 2020
The Dötz benzannulation is a named reaction that utilizes Fischer chromium carbenes in a formal [3+2+1] cycloaddition with an alkyne and CO to produce the corresponding benzannulated product. Since its development in the 1970s, this reaction has been extensively used in the synthesis of natural products and various molecular architectures. Although the reaction sometimes suffers from the formation of other competing side products, the rapid construction of naphthol structures with a 1,4-dihydroxy unit makes it the most appropriate reaction for the synthesis of p-naphthoquinones. This review focuses on our group’s efforts over the past decade on the extensive use of this annulation reaction along with the contributions of others on the synthesis of different natural products.1 Introduction2 General Description and Mechanism of the Dötz Benzannulation Reaction3 Applications of the Dötz Benzannulation in Natural Product Synthesis over the Last Decade4 Conclusion