Development of Rhodium (I) Catalyzed Conjugate Addition Reactions

Undergraduate #173
Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)

Shekinah Graham - Winston Salem State University
Co-Author(s): Briana Graves and Malcolm Jeffries, Winston Salem State University, Winston Salem, NC

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Conjugate addition reaction is one of the most reliable methods in the construction of carbon carbon bonds. Progress in rhodium (I)-complex catalyzed conjugate addition reaction to heterocyclic Michael acceptors is presented. Heterocycles account for more than 50% of all known organic compounds synthesized both by nature and chemists. Heterocycles or heterocyclic subunits are also present in over 75% of the top 200 brand name drugs are. Heterocycles have continued to be the focus of intense synthetic activity both in academia and industry. Many synthetic methods including metal catalyzed reactions have been developed in the efforts to synthesize heterocycles. Metal catalyzed carbon carbon bond formation is very valuable in forming the carbon skeletons of complex heterocycle synthesis. Rhodium catalyzed carboncarbon bond formation reactions using arylboronic acid/organometallic reagents in heterocyclic compounds such as benzopyrans have been developed. Excellent chemical yields have been achieved in all substrates investigated.

Funder Acknowledgement(s): NSF HBCU-UP RIA (NSF No. 1600987)

Faculty Advisor: Fenghai Guo, guof@wssu.edu

Role: I developed the reaction conditions for Rh(I)-complex conjugate addition to N-Boc-4-pyridone. I investigated different ligands and found out BINAP is the optimal ligand for Rh(I) salt catalyzed conjugate addition reactions. A broad of heterocyclic Michael acceptors were investigated for Rh(I)-BINAP conjugate addition reactions. Excellent chemical yields were attained in all cases.