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己二酸是工业上具有重要应用的二元羧酸,其合成方法的研究受到了广泛的关注.其传统的合成方法对环境造成了极大的破坏.利用含钨化合物作为催化剂催化合成己二酸是一种绿色环保的新方法,引起了人们的重视.作者介绍了近年来含钨化合物催化合成己二酸的研究进展,分析比较了不同催化剂体系的研究情况,展望了今后己二酸合成的发展前景. 相似文献
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Cascade Multicomponent Synthesis of Indoles,Pyrazoles, and Pyridazinones by Functionalization of Alkenes
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Dr. Kiran Matcha Dr. Andrey P. Antonchick 《Angewandte Chemie (International ed. in English)》2014,53(44):11960-11964
The development of multicomponent reactions for indole synthesis is demanding and has hardly been explored. The present study describes the development of a novel multicomponent, cascade approach for indole synthesis. Various substituted indole derivatives were obtained from simple reagents, such as unfunctionalized alkenes, diazonium salts, and sodium triflinate, by using an established straightforward and regioselective method. The method is based on the radical trifluoromethylation of alkenes as an entry into Fischer indole synthesis. Besides indole synthesis, the application of the multicomponent cascade reaction to the synthesis of pyrazoles and pyridazinones is described. 相似文献
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Malcolm W.B. McCulloch 《Tetrahedron letters》2005,46(44):7619-7621
The first synthesis of the natural product guieranone A is described, demonstrating a one-pot procedure for the synthesis of protected-1,3,6,8-tetraoxygenated naphthalenes and a subsequent directed metalation synthesis of 2-keto naphthalenes. 相似文献
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A concise and improved stereoselective synthesis of (+)-eleutherin, (+)-allo-eleutherin and the formal synthesis of (+)-nocardione B is described. The synthesis is based on a Dötz benzannulation and an improved oxa-Pictet-Spengler cyclization as the key steps. The synthesis is achieved in six steps in overall yields of 18% for eleutherin and 20% for allo-eleutherin. 相似文献
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A short enantioselective synthesis of (+)-eleutherin, (+)-allo-eleutherin and the formal synthesis of (+)-nocardione B is described. The synthesis is completed in six steps in overall yields of 8% for eleutherin and 14% for allo-eleutherin. The synthetic strategy features an efficient combination of the Dötz annulation reaction with a chiral alkyne and an oxa-Pictet Spengler reaction as the keys steps in the stereodivergent synthesis of (+)-eleutherin and (+)-allo-eleutherin. The synthesis of (S)-(+)-2-(2′-hydroxypropyl)-5-methoxy-1,4-naphthoquinone entails the formal synthesis of (+)-nocardione B. 相似文献
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Radical rearrangements are important transformations in organic synthesis. The stabilisation of alpha-nitrogen radicals is shown to be a useful effect for the control of radical rearrangements and is applied to the synthesis of a variety of azabicyclic frameworks. The utility of this method is illustrated in the synthesis of bioactive targets. 相似文献
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Gary L. Points III Kenneth T. Stout Prof. Christopher M. Beaudry 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(70):16655-16658
A Diels–Alder reaction-based strategy for the synthesis of indoles and related heterocycles is reported. An intramolecular cycloaddition of alkyne-tethered 3-aminopyrones gives 4-substituted indolines in good yield and with complete regioselectivity. Additional substitution is readily tolerated in the transformation, allowing synthesis of complex and non-canonical substitution patterns. Oxidative conditions give the corresponding indoles. The strategy also allows the synthesis of carbazoles. The method was showcased in a formal synthesis of lysergic acid. 相似文献
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Goard M Aakalu G Fedoryak OD Quinonez C St Julien J Poteet SJ Schuman EM Dore TM 《Chemistry & biology》2005,12(6):685-693
The regulation of protein synthesis is vital for a host of cell biological processes, but investigating roles for protein synthesis have been hindered by the inability to selectively interfere with it. To inhibit protein synthesis with spatial and temporal control, we have developed a photo-releasable anisomycin compound, N-([6-bromo-7-hydroxycoumarin-4-yl]methyloxycarbonyl)anisomycin (Bhc-Aniso), that can be removed through exposure to UV light. The area of protein synthesis inhibition can be restricted to a small light-exposed region or, potentially, the volume of two-photon excitation if a pulsed IR laser is the light source. We have tested the compound's effectiveness with an in vitro protein-translation system, CHO cells, HEK293 cells, and neurons. The photo-released anisomycin can inhibit protein synthesis in a spatially restricted manner, which will enable the specific inhibition of protein synthesis in subsets of cells with temporal and spatial precision. 相似文献
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[structure: see text] The total synthesis of the polyether antibiotic ionomycin, a calcium ionophore, is described. The synthesis demonstrates the utility of ring-opening methodologies as applied to the synthesis of polypropionate and deoxypolypropionate subunits, which are found in two of the four fragments in the synthesis. 相似文献
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Murai K Morishita M Nakatani R Kubo O Fujioka H Kita Y 《The Journal of organic chemistry》2007,72(23):8947-8949
The first asymmetric total synthesis of spongotine A is described. The oxidative synthesis of the imidazoline/ketone unit from keto aldehyde and diamine is a key step in this synthesis. The absolute stereochemistry of the asymmetric center of natural spongotine A is revealed as the (S)-configuration. 相似文献
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A concise asymmetric synthesis of (-)-halenaquinone is described. The synthesis features a diastereoselective Heck cyclization to set a quaternary center as well as a novel intramolecular inverse-electron-demand Diels-Alder reaction involving a vinyl quinone. The synthesis is highly convergent and features a minimal amount of protecting group manipulations. 相似文献
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A stereoselective synthesis of (+)-herboxidiene is described. The convergent synthesis utilized a Suzuki cross-coupling reaction to assemble the key segments. The synthesis of the functionalized tetrahydropyran ring utilized an Achmatowicz reaction as the key step. The synthesis of the C10-C19 segment was accomplished using Brown's crotylboration, asymmetric alkylation, and a stereoselective allylic chlorination reactions. 相似文献
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Fabienne Fache 《Tetrahedron》2005,61(22):5261-5266
The synthesis of the biologically active cimiracemate B and some analogs is described. The key step of the synthesis is a coupling between a bromoketone and a cinnamic acid derivative. 相似文献
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[reaction: see text] The synthesis of the highly substituted indole portion of the complex tremorgenic natural products lolicine A and B is presented. The Diels-Alder reaction of a quinone monoimine enables the synthesis of an appropriately substituted indole. The key step in the synthesis is a tandem isopropenyl cuprate addition/aldol cyclocondensation which provides the necessary functionality for elaboration to the 2,2,5,5-tetramethyltetrahydrofuran. 相似文献
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Takaoka LR Buckmelter AJ LaCruz TE Rychnovsky SD 《Journal of the American Chemical Society》2005,127(2):528-529
A synthesis of spiroacetals was developed using a reductive cyclization strategy that leads stereoselectively to spiroacetals with a single anomeric stabilization. The method begins with the synthesis of spiro ortho esters. The ortho ester is converted to a cyano acetal. Reductive lithiation of the cyano acetal generates an axial dialkoxylithium reagent, and intramolecular cyclization produces a new ring with retention of configuration. The strategy is convergent and produces complex spiro acetals in only a few steps. The method will be useful in the synthesis of natural products and will facilitate the synthesis of previously inaccessible contra-thermodynamic acetals. 相似文献
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Solid phase combinatorial synthesis of a library of macro-heterocycles and related acyclic compounds
A solid phase synthesis of macrolactones from three building blocks and in eight steps is described. The synthesis which is carried out on the DHP resin includes Mitsunobu and DIC couplings. The macrocyclization occurs by SN2 displacement of an allylic chloride by a malonate anion. The synthetic methodology is suitable for the synthesis of arrays of macrocycles as well as linear compounds. 相似文献
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Masaki Okamoto 《Research on Chemical Intermediates》2006,32(3):317-330
In the direct synthesis of silicon compounds by reactions of elemental silicon with methyl chloride, methanol and hydrogen
chloride, silylene formed on surface of silicon grains during the reaction is an intermediate. The reaction of surface silylene
with a variety of unsaturated hydrocarbons provides new direct synthesis of organosilanes. In the direct synthesis of methylchlorogermanes
from elemental germanium, surface germylene is not an intermediate, while tetrachlorogermane is synthesized by the direct
reaction of germanium with hydrogen chloride via dichlorogermylene intermediate. Various unsaturated hydrocarbons or organic chlorides added to the system of tetrachlorogermane
synthesis give new methods for the synthesis of organogermanes. 相似文献
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甲烷部分氧化制合成气由于合成气中n(H2)/n(CO)接近2,可直接用于甲醇合成或烃类F-T合成等后续工业过程而在国内外受到了广泛的关注。利用氧载体的氧物种在无气相氧下直接选择氧化甲烷制合成气是天然气化工利用的新方法,本文介绍了该方法的基本原理、概念工艺和对氧载体的性能要求,对应用于该方法的铈基复合氧化物的掺杂和助剂对选择氧化甲烷性能的影响、钙钛矿氧化物氧载体的氧缺陷、氧物种迁移、结构稳定性及其氧物种氧化甲烷的性能进行了阐述和分析,提出了控制氧载体表面状态是获得高合成气选择性的关键,并对该技术今后的研究重点进行了展望。 相似文献