Study of Carbene Intermediates from Sulfonium Ylide Precursors

Abstract

A carbene is a neutral carbon atom that lacks a full octet of electrons, making it a highly reactive intermediate. The carbene intermediate has two non-bonding electrons which can be spin paired (singlet state) or occupy two separate orbitals (triplet state). Carbenes naturally occur in interstellar space under low pressures and temperatures, making collisions between carbenes rare. The study of carbene intermediates aids in the application of forming new carbon-carbon bonds, assisting in the development of pharmaceutical applications such as anti-cancer agents. Due to their unstable nature, precursor molecules are generally synthesized to study carbene intermediates. Sulfonium ylides offer a direct pathway to carbene intermediates. This project aims to synthesize a series of sulfonium ylide derivatives with varying functional groups to study the impact of variations of electronic structure on carbene intermediate prevalence and spin state. Two synthetic intermediates, 3-methylbenzoyl chloride and 1,3-di-(3-methylphenyl)-1,3-propanedione, were successfully synthesized, isolated, and characterized by 1H NMR, GC-MS, and IR spectroscopy.