Regioselective Radical Cascade Cyclizations of Alkyne-Tethered Cyclohexadienones with Chalcogenides under Visible-Light Catalysis.

ABSTRACT: Herein, we demonstrated a silver/K₂S₂O₈-mediated highly regio- and diastereoselective 6/5-exo trig radical cascade cyclization of alkyne-tethered cyclohexadienones with sulfonyl hydrazides or sodium sulfinates and subsequent selenation to access 6,6-dihydrochromenone and 6,5-fused tetrahydro benzofuranone derivatives. This reaction protocol features high functional group compatibility and has a wide substrate scope providing a variety of dihydrochromenones and tetrahydro benzofuranone derivatives in good to excellent yields. The reaction proceeds via the attack of a sulfonyl radical to alkyne over the activated Michael acceptor. The TEMPO quenching experiment implies the presence of a radical intermediate. Further synthetic versatility of 6,6- and 5,

SUBMITTER: Prasad VS 

PROVIDER: S-EPMC10552108 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature