Project Summary/Abstract Our research goal is to develop new catalytic technologies for the rapid synthesis and late-stage functionalization under mild reaction conditions of complex, biorelevant molecules. Our research efforts have been directed to exploit visible-light-induced excited-state catalysis, a process that involves at least one photoexcited catalytic species, to address unmet challenges in organic synthesis. Excited-state catalysis involves the photoexcitation of catalytic organic or organometallic compounds that allows access to their excited- state landscapes for the development of previously elusive synthetic transformations. This proposal aims to continue our efforts in establishing novel excited-state catalytic platforms for the synthesis of valuable fluorinated compounds, the derivatization of carbonyl moieties, and the site-selective functionalization of carbohydrates. More specifically, we will develop (i) polyfluoroalkoxylation reactions of various hydrocarbons via excited-state catalysis; (ii) new redox-active reagents such as those that can be used for pentafluorosulfenylation and fluorosulfonylation; (iii) regioselective polyfluoroalkoxylation reactions of arenes and heteroarenes through metallaphotocatalysis; (iv) new excited-state catalysts to modulate the reactivity of carbonyl compounds; and (v) site-selective functionalization of carbohydrates. Since fluorinated compounds, carbonyl derivatives, and functionalized sugars are ubiquitous in natural products, therapeutics, imaging agents, fine chemicals, and biomaterials, successful development of the proposed research will allow convenient access to and the studies of numerous new functional molecules to aid the discovery and development of new drugs, agrochemicals, bio- probes, and polymers.