β-Alkynyl ketones are key precursors in the synthesis of biologically interesting oxa-cyclic compounds. They can undergo intramolecular oxo-cyclization in the presence of transition metal, forming the metal-containing carbonyl ylides, which have been widely applied in organic synthesis. Recently, we described the enantioselective tandem reaction of β,γ-unsaturated α-ketoesters with β-alkynyl ketones by a bimetallic catalytic system of achiral AuIII salt and chiral N,N'-dioxide-MgII complex. The cycloisomerization of β-alkynyl ketone and asymmetric intermolecular [4+2] cycloaddition with β,γ-unsaturated α-ketoesters subsequently occured, providing an efficient and straightforward access to chiral multifunctional 6,6-spiroketals in up to 97% yield, 94% ee and &gt; 19/1 d.r., which are important skeletons in many natural products and chiral ligands. Besides, a catalytic cycle was proposed based on the results of control experiments.

Bimetallic catalytic asymmetric tandem reaction of β-alkynyl ketones to synthesize 6,6-spiroketals

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.