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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Catalytic Cyclotrimerization Pathway for Synthesis of Selaginpulvilins C and D: Scope and Limitations
Lukas Rycek1, Miguel Mateus1, Nela Beytlerová1
1Department of Organic Chemistry, Faculty of Science, Charles University, Albertov 6, 128 43 Praha 2, Czech Republic.
Abstract:
A facile and unified approach to the main selaginpulvilin's framework was achieved by catalytic [2 + 2 + 2]-cyclotrimerization of a triyne with monosubtituted alkynes. The reaction proceeded with high "ortho" selectivity by using Wilkinson's catalyst (RhCl(PPh3)3) under ambient conditions with reasonable yields. The scope of the reaction with respect to the alkyne as well as the catalytic system was evaluated. The formal total modular syntheses of selaginpulvilin C and D were accomplished by transformation of the cyclotrimerization's products.
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