Topic
Annulation
About: Annulation is a research topic. Over the lifetime, 10152 publications have been published within this topic receiving 189701 citations.
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TL;DR: In this article, a new fulvene synthesis results from the palladium-catalyzed [2 + 2+2] annulation of 1 mol of a β-substituted vinyl iodide and 2mol of a monosubstitized acetylene.
Abstract: A new fulvene synthesis results from the palladium-catalyzed [2+2+2] annulation of 1 mol of a β-substituted vinyl iodide and 2 mol of a monosubstituted acetylene. This variant of the Heck reaction tolerates a wide range of substrate substituents with the best results obtained by using the catalyst, Pd(CH 3 CN) 2 Cl 2 . Addition of Cu I I to the reaction affords high yields of 1,3-enyne and no fulvene. A [6.5]spiro system is formed from 4-tert-butyl-1-cyclohexenyl triflate and a biphenyl is formed from 1-aryl-1-bromoethene under these conditions. A mechanism for this novel fulvene synthesis is proposed
80 citations
80 citations
TL;DR: In this paper, pyrene-fused porphyrins via the oxidative intramolecular ring closure reactions of meso-pyrenylporphyrin were prepared.
Abstract: We prepared novel pyrene-fused porphyrins via the oxidative intramolecular ring closure reactions of meso-pyrenylporphyrin. The excitation energies and the oxidation potentials of the isolated dark...
80 citations
TL;DR: The described strategy, taking advantage of chiral sulfur ylides, represents a direct procedure to access chiral 2-substituted indolines.
Abstract: Get asymmetric! Asymmetric [4+1] annulation of sulfur ylides and N-(ortho-chloromethyl)aryl amides allowed the formation of the desired cycloadduct with moderate to high yields and enantioselectivities (see scheme). The described strategy, taking advantage of chiral sulfur ylides, represents a direct procedure to access chiral 2-substituted indolines.
80 citations
TL;DR: This is the first time that ortho-quinone methides are employed in phosphine-mediated cyclization reactions, and the method led to the formation of chromane derivatives in high yields and excellent enantioselectivity.
80 citations