ABSTRACT
Chiral coumarins and their derivatives are ubiquitous structural motifs found in an array of biologically and therapeutically active natural products and drugs. Herein, a highly enantioselective dual remote copper-catalyzed vinylogous alkynylallylic substitution of yne-allylic esters with coumarins has been developed. The practicality of this method is exemplified by the use of readily available starting materials; mild reaction conditions; excellent regio-, enantio-, and stereoselectivities; and the very broad substrate scope (67 examples), while the scalability and further applications of this method are illustrated by the gram-scale reaction and the series of derivations of the products.
ABSTRACT
Impressive progress has been made in the copper-catalyzed asymmetric propargylic substitution (APS) reaction, but its use in remote asymmetric yne-allylic substitution remains a challenging topic. Herein, we report the first remote enantioselective copper-catalyzed sulfonylation of yne-allylic esters with sodium sulfinates. The reaction is assumed to occur via a copper-vinylvinylidene species as the key reactive intermediate. The use of readily available starting materials, the mild reaction conditions, and the excellent regio-, enantio- and stereoselectivity, as well as broad substrate scope (>70 examples), show the practicality and attractiveness of this method.