Chemistry Colloquium: Marvin Parasram

The Department of Chemistry in the College of Arts and Sciences is pleased to welcome Dr. Marvin Parasram, an assistant professor at New York University.

Title: Anaerobic Heteroatom Transfer Reactions Promoted by Photoexcited 1,3-Dipoles

Abstract:

Heteroatom units, such as carbonyls, alcohols and amines, are prevalent motifs in many medicinally important compounds. Methods to incorporate these important functional groups at the expense of hydrocarbons rely on the use of non-commercial heteroatom transfer agents, precious transition metals, and/or costly engineered enzymes. Also, these methods often require exogenous oxidants to promote the C–heteroatom bonding event, which greatly limits substrate scope. Our laboratory focuses on the employment of economical 1,3-dipoles as versatile reagents that can serve as the hydrocarbon activator and the heteroatom atom source for the heteroatom incorporation of aliphatic systems under benign visible-light irradiation. Our contributions involve the cleavage of alkenes leading to valuable carbonyl derivatives and the direct C–H oxidation of hydrocarbons via anaerobic oxygen-atom transfer from photoexcited nitroarenes. Using photoexcited azoxys, an anaerobic nitrogen atom transfer event can occur leading to the aziridination of alkenes. Mechanistic studies reveal that the 1,3-dipoles are the sole photo-absorbing species, which leads to the formation of diradical intermediates that are responsible for heteroatom transfer events.