Sequential hydroarylation/Prins cyclization: an efficient strategy for the synthesis of angularly fused tetrahydro-2H-pyrano[3,4-c]quinolines

Abstract

Various aldehydes undergo a smooth cascade cyclization with N-(5-hydroxypent-2-yn-1-yl)-4-methyl-N-phenylbenzenesulfonamide in the presence of 10 mol% Ph₃PAuCl/AgSbF₆/In(OTf)₃ to furnish the corresponding tetrahydro-2H-pyrano[3,4-c]quinoline derivatives in good yields with high selectivity. This is the first report on the synthesis of tetrahydro-2H-pyrano[3,4-c]quinolines through a tandem hydroarylation/Prins cyclization process.