title: Visible Light-Gated Cobalt Catalysis for a Spatially and Temporally Resolved [2+2+2] Cycloaddition.
abstract: The ability to exert spatial and temporal control over a transition-metal catalyst offers diverse opportunities for the fabrication of functional materials. Using an external stimulus such as visible light to toggle a catalyst between an active and dormant state has proven to be an effective approach for controlled, radical methodologies. Outside of radical bond formation, there is a dearth of evidence that suggests traditional transition metal catalysis can similarly be controlled with visible light energy. Many cobalt complexes that catalyze the [2+2+2] cycloaddition are assisted by UV photolysis, but strict photocontrolled methods are unattainable due to high levels of thermally driven reactivity. Herein, we disclose the first light-controlled, cobalt-catalyzed [2+2+2] cycloaddition via a dual cobalt and photoredox catalyst manifold. We demonstrate the power of this method with a spatially and temporally resolved technique for arene formation using photolithography.
authors.affiliation: Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States.|Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Kyle E
authors.initials: KE
authors.lastname: Ruhl
authors.affiliation: Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States.|Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Tomislav
authors.initials: T
authors.lastname: Rovis