Copper-Catalyzed Cyclization/Oxidation/Aromatization Cascade: Efficient Synthesis of Trifluoromethylated Pyrrolo[2,1-α]isoquinolines.

An efficient copper-catalyzed synthesis of 3-(trifluoromethyl) pyrrolo[2,1-α]isoquinolines was achieved through a sequential one-pot two-step three-component reaction of a substituted isoquinoline, a terminal aryne, and methyl 4,4,4-trifluorobut-2-ynoate, with air as an oxygen source. This oxidative cyclization proceeds through an initial copper(I)-catalyzed C–H alkynylation to give alkynyl-1,2-dihydroisoquinolines that subsequently undergo a copper(II)-assisted intramolecular cyclization under mild conditions to give the desired products in moderate to excellent yields. [ABSTRACT FROM AUTHOR]