Diastereoselective syntheses of substituted cis-hydrindanones featuring sequential inter- and intramolecular Michael reactions
作者:Junjia Liu、Maurice A. Marsini、T. Aaron Bedell、Paul J. Reider、Erik J. Sorensen
DOI:10.1016/j.tet.2016.03.039
日期:2016.6
substituted cis-1-hydrindanones enabled by a sequence of Michael reactions. A copper-catalyzed intermolecular Michael addition of a cyclic silyl ketene acetal to a β-substituted-α-alkoxycarbonyl-cyclopentenone enables construction of a quaternary center and is followed, after incorporation of an additional Michael acceptor, by a second, intramolecular addition of a nucleophilic β-ketoester. This strategy affords
Lewis Acid Catalyzed Intramolecular [3+2] Cross-Cycloaddition of Donor-Acceptor Cyclopropanes with Carbonyls: A General Strategy for the Construction of Acetal[n.2.1] Skeletons
作者:Siyang Xing、Yan Li、Zhen Li、Chang Liu、Jun Ren、Zhongwen Wang
DOI:10.1002/anie.201106368
日期:2011.12.23
Build a bridge: The first catalytic intramolecular [3+2] cycloaddition of monodonor–monoacceptor cyclopropanes (see scheme) provides a general and efficient strategy for construction of structurally diverse acetal[n.2.1] and 1,4‐dioxygen‐substituted cyclic skeletons, which are widely distributed in biologically important natural products.
Catalytic, enantioselective, tandem carbonylylide formation/cycloaddition of 2-diazo-3,6-diketoester 2 with the use of dirhodium tetrakiscarboxylate and tetrakisbinaphtholphosphate catalysts to give the cycloadducts 3 in good yields and up to 90% ee is described.
Zirconocene-Induced Cocyclisation/Elimination Reactions of 2-Heterosubstituted 1,6-Dienes and 1,6-Enynes
作者:Richard J. Whitby、David R. Owen
DOI:10.1055/s-2005-870029
日期:——
Zirconocene-mediated cocyclisation of 2-heterosubstituted-1,6-dienes and -enynes gave zirconacycles bearing an endocyclic β-leaving group which eliminated under the reaction conditions to provide exocyclic alkylidene groups. The scope of this cyclisation/elimination has been investigated along with further elaboration of the monosubstituted zirconocene intermediates by insertion of alkenyl carbenoids.