The Oxidative Annulation of Tertiary Benzyl Alcohols with Internal Alkynes using an (Electron-Deficient η5-Cyclopentadienyl)Rhodium(III) Catalyst under Ambient Conditions

It has been established that a dinuclear (electron-deficient (5)-cyclopentadienyl)rhodium(III) complex catalyzes the oxidative annulation of tertiary benzyl alcohols with internal alkynes via sp(2) CH/OH functionalization under ambient conditions (at room temperature under air) to give substituted isochromenes in good yields. The preference for annulation across electron-rich substrates over electron-deficient substrates was observed using this electron-deficient rhodium(III) complex.