New Picropodophyllin Analogs via Palladium-Catalyzed Allylic Alkylation− Hiyama Cross-Coupling Sequences

…, D Lopes, D Madec, C Kammerer, G Poli…

Index: Kammerer, Claire; Prestat, Guillaume; Gaillard, Thomas; Madec, David; Poli, Giovanni Organic Letters, 2008 , vol. 10, # 3 p. 405 - 408

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Citation Number: 24

Abstract

Unsaturated malonyl esters underwent Pd-catalyzed intramolecular allylic alkylation to give 4-vinyl-substituted γ-lactones. In contrast to the formerly studied cyclization of malonamides, this reaction could be achieved only with a substrate incorporating a suitably positioned silicon moiety, which directs the ionization toward the desired η 3-allylpalladium complex. The resulting 4-[dimethyl-(2-thienyl) silylvinyl] lactone could be subsequently engaged ...