With this RUI Award, the Chemical Synthesis Program is supporting the research of Professor LuAnne McNulty of Butler University to study the preparation and reactions of alkenyl cyclic boronic half esters. Alkenyl cyclic boronic half esters are readily prepared by transesterification of homoallylic alcohols with alkenylboronic acids, followed by ring closing metathesis. Alkenyl cyclic boronic half esters are suitable substrates for Suzuki-Miyaura cross-coupling reactions with aryl halides and beta-halo-alpha,beta-unsaturated electrophiles. The Suzuki-Miyaura affords products that are capable of undergoing an intramolecular oxa-Michael reaction to generate dihydropyrans. The optimization of a single pot tandem Suzuki-Miyaura/Michael reaction will be studied through the modification of the base beta-halo-alpha,beta-unsaturated electrophiles used in the coupling reaction.
The proposed work strives to provide an alternate method to the preparation of dihydropyrans, common natural product substructural units. In addition, the work could allow one to set multiple stereoisomers of the same dihydropyran by modification of substituents on the precursor alkenyl cyclic boronate. The educational broader impacts of this project involve training undergraduate students. The PI will continue her strong history of mentoring women in synthetic research. Undergraduate students that participate in this project will gain valuable experience in modern synthetic chemistry, including organo-boron and transition metal-mediated chemistry, and will have opportunities to present their work at regional and national meetings.