A concise indium(III)-catalyzed annulation of 2,3-disubstituted indoles with o-aminobenzyl alcohols is reported. The in situ generated aza-ortho-quinone methides (aza-oQMs) were efficiently trapped by diverse carbazoles in a formal [4+2] cycloaddition reaction catalyzed by indium(III) triflate, which provided rapid access to bridged polycyclic indoline alkaloid skeletons.