Dienol tautomers 2 of 2-acceptor-substituted cycloalkenones 1 undergo an iron(III)-catalyzed reaction sequence – formally a vinylogousMichaelreaction – with benzoquinone derivatives 5 to yield products 6, 7 and 9, which are easily converted into highly functionalized biarylcompounds.
cycloalkenones 1 undergo an iron(III)-catalyzed vinylogousMichaelreaction − a sequence of enone−dienol tautomerism, [4+2]-cycloaddition, and retro-aldol reaction − with quinone derivatives 3. A variety of products is obtained ranging from meta-terphenyl precursors 5 to dihydronaphthobenzofurans 7. Reaction of 1,2-naphthoquinone (3e) with vinylogous donors 1 yields cross-coupled products 12, which