Copper Catalyzed C-C Bond Formation with Ynamides and Fluorinated Enolates

Abstract

The addition of ynamides to N-heterocycles activated in situ with ethyl chloroformate has been accomplished at room temperature using copper iodide as catalyst. The addition to pyridines and quinolines proceeds with good to high regioselectivity, producing the corresponding 1,2-dihydro-N-heterocycles in up to 95% yield.

Asymmetric synthesis of α-chloro-α-fluoro-β-hydroxyl ketones was achieved with up to 99% yield through the aldol reaction of in situ generated α-chloro-α-fluoroenolates with 4-bromobenzaldehyde catalyzed by copper-bisoxazoline complexes under mild condition.