Journal ArticleDOI
Oxacycloalkenyliden-Komplexe von Chrom, Molybdän und Wolfram: Synthese, Anellierung mit Alkinen und Diels-Alder-Reaktionen mit Dienen
TLDR
In this article, the reaction of the chromium complex with tolan leads to an acyl hydroquinone derivative and the tungsten complex with cyclopentadiene leads to two diastereomeric oxatricyclic carbene complexes with an endo/exo selectivity of 3:1.Abstract:
Reactions of Complex Ligands, LXI[1]. - Oxacycloalkenylidene Complexes of Chromium, Molybdenum, and Tungsten: Synthesis, Their Annulation with Alkynes and Diels-Alder Reaction with Dienes
Lithiiated propargylic ether 1 reacts with M(CO)6 (M = Cr, Mo, W) to give the 2-oxacyclic carbene complexes 2–4 containing an α,β-double bond and a cyclic acetal structure which serves as a protected benzoyl group. Reaction of the chromium complex 2 with tolan leads to an acyl hydroquinone derivative 5. The tungsten complex 3 undergoes a [4 + 2] cycloaddition with cyclopentadiene to give two diastereomeric oxatricyclic carbene complexes 6 and 7 with an endo/exo selectivity of 3:1. The stereochemistry of the Diels-Alder reaction is controlled by the configuration of the acetal carbon center.read more
Citations
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Journal ArticleDOI
Fischer Carbene Complexes in Organic Synthesis: Metal-Assisted and Metal-Templated Reactions
Karl Heinz Dötz,Joachim Stendel +1 more
TL;DR: This review concentrates on group 6 metal carbene complexes with a special focus on chromium complexes since, because of their balance of reactivity and stability combined with easy accessibility, they are the most prominent members of the Fischer carbenes and have found the broadest application.
Journal ArticleDOI
Fischer Carbene Complexes as Chemical Multitalents: The Incredible Range of Products from Carbenepentacarbonylmetal alpha,beta-Unsaturated Complexes.
TL;DR: Beyond doubt, the methodological arsenal of preparative organic chemistry cannot be imagined any more without the valuable transformations of the Fischer carbene complexes; it only remains to be seen whether one or other of the numerous new types of cocyclization products of these complexes can establish itself as a lead structure in the search for biologically active compounds.
Book ChapterDOI
(1-Alkynyl)carbene Complexes (= 1-Metalla-1-buten-3-ynes): Tools for Synthesis
Rudolf Aumann,Hubert Nienaber +1 more
TL;DR: In this article, the reactivity of (1-alkyny1) carbene complexes is discussed, especially if a regio-and/or stereoselective formation of C,C- or C,X bonds is achieved that might be utilized in organic synthesis.
Journal ArticleDOI
Fischer-Carbenkomplexe als chemische Multitalente: die unglaubliche Produktpalette ausα,β-ungesättigten Carbenpentacarbonylmetall-Komplexen
TL;DR: The Fischer-Carben-Komplexe as mentioned in this paper is a formal cycloaddition of α,β-ungesattigten carbenmetall-komplexen an alkine unter CO-insertion.
Journal ArticleDOI
Cycloisomerization of Alkynols at Transition Metal Templates
TL;DR: The metal-assisted cycloisomerization of ω-alkynols to oxacycloalkylidene complexes is reviewed in this article, where a variety of low-valent coordinatively unsaturated transition metal templates from group 6 to 10 mediate the cyclization of butynols, -pentynols and -hexynols.
References
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Journal ArticleDOI
Building Bridges Between Inorganic and Organic Chemistry (Nobel Lecture)
TL;DR: In this article, a lecture dedicated to the late Robert B. Woodward, a supreme patterner of chaos, was given. And it is our collaboration on orbital symmetry conservation, the electronic factors which govern the course of chemical reactions, which is recognized by half of the 1981 Nobel Prize in Chemistry.
Journal ArticleDOI
Carbene Complexes in Organic Synthesis [New Synthetic Methods (47)]
TL;DR: Carbene complexes have been shown to be suitable as carbene-transfer agents and undergo interesting cycloadditions with other ligands in the co-ligand sphere as mentioned in this paper.