[2+2] Photocycloadditions and Photorearrangements of 2-Alkenylcarboxamido-2-cycloalken-1-ones
作者:Catherine Meyer、Olivier Piva、Jean-Pierre Pete
DOI:10.1016/s0040-4020(00)00366-5
日期:2000.6
photolysis of 2-alkenylcarboxamido-2-cycloalken-1-ones led regio- and stereospecifically to a faster [2+2] intramolecular reaction and therefore to the corresponding cyclobutanes. However, photorearrangements involving three different intramolecular H-abstraction processes, compete with the observed cycloaddition. To explain the results, we propose that different deactivation pathways are available
The beneficial effect of microwave irradiation versus classical thermal conditions is demonstrated through a series of comparative cross-metathesis reactions.
微波辐射相对于传统热条件的有益效果通过一系列比较的交叉转烯反应得以证明。
Chemoselective Carbozincation of Cyclopropene for C-C Bond Formation and Cleavage in a Single Operation
cyclopropene and cleavage of cyclopropylzinc generates carbanion intermediates, which in turn can generate oligomeric complexes in situ through successive carbozincation reactions. The present reaction controls the carbozincation sequence and C–C bondcleavage to give densely functionalized and sterically congested alkylamines in a single operation. A subtle difference in the substituent at the C=N bond induced
An amidine containing at least one structural unit of the formula (I) and the use thereof as catalyst for the crosslinking of a functional compound, especially of a polymer having silane groups. The amidine is preparable in a simple process from readily available starting materials, is largely odorless at room temperature and is of low toxicity. It accelerates the crosslinking of functional compounds surprisingly efficiently and can be adjusted for optimal compatibility with different compositions via the radical to which the structural units of the formula (I) is bonded, which means that such compositions do not have a tendency to migration-related defects such as separation, exudation or substrate soiling.
Die vorliegende Erfindung beschreibt ein Amidin enthaltend mindestens eine Struktureinheit der Formel (I), sowie dessen Verwendung als Katalysator für die Vernetzung einer funktionellen Verbindung, insbesondere eines Silangruppen aufweisenden Polymers.
Das beschriebene Amidin ist in einem einfachen Verfahren aus gut erhältlichen Grundstoffen herstellbar, bei Raumtemperatur weitgehend geruchlos und wenig toxisch. Es beschleunigt die Vernetzung von funktionellen Verbindungen überraschend gut und kann über den Rest, an welchen die Struktureinheit der Formel (I) gebunden ist, auf eine optimale Verträglichkeit mit unterschiedlichen Zusammensetzungen hin eingestellt werden, wodurch solche Zusammensetzungen nicht zu migrationsbedingten Fehlern wie Separation, Ausschwitzen oder Substratverschmutzung neigen.