1,721,163 research outputs found
Selective palladium-mediated carbon-oxygen bond and carbon-sulfur bond forming reactions and their application to the synthesis of structural analogues of strobilurins and some naturally-occurring sulfur-containing carboxyamides
No full textRegioselective functionalization of the imidazole ring via transition metal-catalyzed C–N and C–C bond forming reactions
No full textFunctionalized imidazole derivatives in- clude compounds that are known to possess a broad range of significant biological properties or are im- portant templates in medicinal chemistry. In the light of the importance of these heteroaromatic com- pounds a great deal of attention has been given to their synthesis and, in the past years, a number of methods has been described in the literature allow- ing for the construction of the heteroaromatic core of these substances by cyclization protocols. Howev- er, in recent years, much more attention has been fo- cused on the design and development of efficient protocols that are based on the selective functionali- zation of the imidazole ring at the N-1, C-2, C-4 or C-5 position via transition metal-catalyzed reactions and enable the synthesis of imidazole derivatives, in- cluding bioactive and/or naturally occurring com- pounds, which cannot be accessed by other means. This critical review with 439 references covers devel- opments in this hot area of research up to July 2009 and includes a description of synthetically important, regioselective transition metal-catalyzed Csp2-N, Csp-N, Csp3-N, Csp2-Csp2, and Csp-Csp2 bond form- ing methods, their applications, and limitations
Mucochloric and mucobromic acids: Inexpensive, highly functionalised starting materials for the selective synthesis of variously substituted 2(5H)-furanone derivatives, sulfur- or nitrogen-containing heterocycles and stereodefined acyclic unsaturated dihalogenated compounds
No full text2(5H)-Furanone derivatives are a large family of heterocycles that include synthetically useful compounds. several natural products and drugs with diverse biological activities. From the 1960 there has been a Continuous interest in the development of efficient methods for preparation of these heterocycles and in their synthetic applications. The Studies in these fields have been summarised and discussed in several excellent reviews., some of which have been recently published. The present article aims at completing the picture of these Studies and highlights the most recent results from our and other and Our laboratories which have been considered Only Shortly in previous reviews or have not been reviewed at all. In particular, it deals with the preparation and reactivity of 3.4-dichloro-5-hydroxy-2(5H)-furanone (also called mucochloric acid) and 3,4-dibromo-5-hydroxy-2(5H)-furanone (also called mucobromic acid) and the synthetic applications of these inexpensive, highly functionalised synthons. These applications illustrate that these mucohalic acids can provide a simple and convenient entry to a wide variety of interesting organic compounds and are mainly concerned with the selective and efficient preparation of variously substituted 2(5H)-furanone derivatives, including natural and unnatural compounds. which exhibit antiinflammatory activity or are characterised by potent cytotoxic activities against human cancer cell lines. Nevertheless, our attempt to tell the "whole story" of mucochloric and mucobromic acids from 1873 up to the present day is also concerned with a discussion on the use of these substances for preparation of stereodefined acyclic unsaturated dihalogenated derivatives and sulfur- or nitrogen-containing heterocycles, including members. which are precursors to agrochemically important substances
Synthesis of natural and unnatural cytotoxic (Z)-4-aryl-5-[1-(aryl)methylidene]-3-halo-2(5H)-furanones and a precursor to nostoclides I and II
No full textMild Pd/Cu-Catalyzed Sila-Sonogashira Coupling of (Hetero)aryl Bromides with (Hetero)arylethynylsilanes under PTC Conditions
No full textThe palladium/copper cocatalyzed sila-Sonogashira reaction of (hetero)arylethynysilanes with (hetero)aryl bromides in toluene and water at 40 ̊C under PTC conditions gave the required di(hetero)arylethynes in moderate to high yields. Activated, deactivated and ortho-substituted (hetero)aryl bromides are well tolerated. This protocol also allowed the preparation of symmetrical diarylethynes by double arylation of 1,2-bis(trimethylsilyl)ethyne
Selective transition metal-promoted carbon-carbon and carbon-heteroatom bond formation. A review
No full textSynthesis and antitumoral activities of 3,4-diaryl-2(5H)-furanones, 4-(1-alkynyl)-3-bromo-2(5H)-furanones and 4-(1.alkynyl)-3-aryl-2(5H)-furanones
No full textSynthesis and antitumoral activitites of 3,4-diaryl-2(5H)-furanones and 4-(1-alkynyl)-3-bromo-2(5H)-furanones
No full textAn efficient and inexpensive multigram synthesis of 3,4-dibromo- and 3,4-Dichlorofuran-2(5H)-one
No full textThe efficient and inexpensive synthesis of 3,4-dibromo- and 3,4-dichloro-2(5H)-furanone on a multigram scale by sodium borohydride reduction of mucobromic and mucochloric acid, respectively, is reporte
Recent advances in the synthesis of (hetero)aryl-substituted heteroarenes via transition metal-catalysed direct (hetero)arylation of heteroarene C–H bonds with aryl halides or pseudohalides, diaryliodonium salts, and potassium aryltrifluoroborates
No full textNo available abstrac
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