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Michel Franck-Neumann Philippe Geoffroy Dominique Gassmann Alain Winling 《Tetrahedron letters》2004,45(28):5407-5410
A series of diazoketones tethered to tricarbonyliron coordinated dienes at the terminal position have been synthesized, and their decomposition reactions as carbene precursors studied. Intermolecular reactions with nucleophilic olefins were observed with Cu(acac)2 as catalyst, the tricarbonyliron playing the role of an efficient protecting group of the diene fragment. With rhodiumII acetate, intramolecular reactions predominate, with formation of five-membered rings, in the side chain, or less commonly, as a cyclopentenone joined side by side to a rearranged diene ligand. Unusually, due to cationic stabilization by the iron, six-membered rings in the side chain are also formed here. A still different reaction was observed during the thermal decomposition of a diazoketone tethered to a coordinated diene at position 2: the formation of a stable complex of a cyclohexa-2-4-dienone (iron assisted carbene reaction and multiple hydrogen migrations). 相似文献
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Corinne Coutant Dr. Paul De Bonfils Dr. Pierrick Nun Dr. Vincent Coeffard 《Chemical record (New York, N.Y.)》2023,23(7):e202300042
Over the past decades, the advent of asymmetric organocatalysis has changed the way chemists think about creating or breaking chemical bonds, enabling new enantioselective strategies for functionalized molecules. The success of asymmetric organocatalysis is notably based on the existence of various activation modes, leading to countless transformations, and on the vast array of available chiral organic catalysts. Breakthroughs in this area have also been driven by selective functionalization of compounds with multiple activation sites such as cyclohexanone-derived dienones. These platforms can undergo diverse transformations such as Michael addition, Friedel-Crafts alkylation or Diels-Alder cycloaddition that offer new opportunities for reaching natural products and biologically relevant compounds. Amongst cyclohexanone-derived dienones, the 2,5-cyclohexadienone motif has received a great deal of attention due to its reactivity pattern and recently, (cross)-conjugated cyclohexanone-derived substrates have also been considered. In this review, we discuss the intermolecular functionalization of (cross)-conjugated cyclohexanone-derived compounds employing asymmetric organocatalysis. 相似文献
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Todd A. Wenderski 《Tetrahedron》2010,66(31):5873-7859
The oxidative dearomatization of resorcinol derivatives, which are outfitted with a lactic acid derived chiral tether, and mitigated by hypervalent iodine derivatives of PhIO, affords stable chiral cyclohexadienones as useful building blocks for the construction of many highly functionalized chiral six and seven-membered ring systems. Herein, we report a multitude of remarkable and unexpected diastereoselective transformations stemming from these cyclohexadienone adducts. 相似文献
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Tetsuya Tsujihara Moriho Tomeba Shigeaki Ohkubo-Sato Kyoko Iwabuchi Rino Koie Natsumi Tada Satoru Tamura Tsunayoshi Takehara Takeyuki Suzuki Tomikazu Kawano 《Tetrahedron letters》2019,60(42):151148
The one-pot reactions of catalytically generated bicyclic zinc enolate with various electrophiles are reported. The zinc enolate as a key intermediate is efficiently delivered from Ni-catalyzed reductive cyclization of alkynyl cyclohexadienone. Employing aldehydes, imine, nitroalkene, and α,β-unsaturated carbonyl compounds as electrophiles, this new class of one-pot reactions gave multi-functionalized cis-hydrobenzofurans and octahydro-4,7-ethanobenzofuran-9-one derivatives in moderate to good yields. 相似文献
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