title: Synthesis of fluorenes via tandem copper-catalyzed [3 + 2] cycloaddition and rhodium-catalyzed denitrogenative cyclization in a 5-exo mode from 2-ethynylbiaryls and N-sulfonyl azides in one pot.
abstract: An efficient synthetic method of fluorenes having an enamine moiety at C-9 methylene bridge is developed from N-sulfonyl-4-biaryl-1,2,3-triazole derivatives via Rh-catalyzed denitrogenative cyclization in a 5-exo mode. Rh-catalyzed denitrogenative cyclization followed by catalytic hydrogenation produces N-tosylaminomethyl-substituted fluorenes in one pot. Moreover, fluorenes are synthesized via tandem Cu-catalyzed [3 + 2] cycloaddition and Rh-catalyzed denitrogenative cyclization in a 5-exo mode starting from 2-ethynylbiaryls and N-sulfonyl azides in one pot.
authors.forename: Boram
authors.initials: B
authors.lastname: Seo
authors.forename: Woo Hyung
authors.initials: WH
authors.lastname: Jeon
authors.forename: Jaeeun
authors.initials: J
authors.lastname: Kim
authors.forename: Sunghwa
authors.initials: S
authors.lastname: Kim
authors.forename: Phil Ho
authors.initials: PH
authors.lastname: Lee