Highly enantioselective Friedel–Crafts alkylation of indole and pyrrole with β,γ-unsaturated α-ketoester catalyzed by chiral dicationic palladium complex
The chiral dicationic Pd complexes, bearing sterically demanding diphosphine ligands as Lewis acid catalysts, are shown to catalyze the asymmetric Friedel–Crafts (F–C) alkylations of indoles and pyrroles with β,γ-unsaturated α-ketoesters, to provide the F–C alkylation products with benzylic stereocenters in high yields and enantioselectivities. The reactive chelated structure, formed by the chiral dicationic
The first de novo synthesis of a β-C-naphthyl glycoside displaying a convenient functionality for subsequent transformations into complex C-arylglycosides is reported. The synthesis of this (±)-β-C-1,5-dibenzyloxynaphthyl 6,6,6-trifluoro-3-amino glycoside relies on a hyperbaric HDA reaction involving a new 2-vinylnaphthalenic dienophile.
据报道,β- C-萘基糖苷的首次从头合成显示出用于随后转化为复杂的C-芳基糖苷的便利功能。该(±)-β - C - 1,5-二苄氧基萘基6,6,6-三氟-3-氨基糖苷的合成依赖于高压HDA反应,该反应涉及新的2-乙烯基萘二烯。