Bachelor of Arts
David J. Gorin
C-O methylation, Organometallic compounds, Methylation, Phenol, Boron, Acids, Copper catalysts, Chan-Lam, Cross coupling, Boronic acids, Phenol-Methylation, Chemical reactions
O-methylation is a ubiquitous process in organic chemistry and biotransformation. The majority of the methylating reagents are electrophiles such as methyl iodide, dimethyl sulfate and diazomethane. Unfortunately, these electrophilic reagents are either unstable or toxic. To avoid the use of hazardous electrophiles and expand the substrate scope, it is necessary to explore new methylating reagents taking alternate mechanistic pathways. To achieve this goal, one strategy is to find nucleophilic methyl sources that are safe to handle.
The Chan-Lam reaction, which is the coupling of heteroatom nucleophiles with aryl boronic acids in presence of copper catalysts, has mostly been used in N- and O- arylation. Herein, we report that based on previous success in carboxylic acid methylation and N-alkylation via the Chan-Lam reaction, we have developed new Chan-lam conditions to methylate phenols with methylboronic acid. The conditions were optimized to give 85% yield on 4-fluoro phenol. The reaction was tested mostly on para-substituted phenols. The mechanism was also investigated.
Further experiments need to be done to expand the substrate scope, improve the yield of certain substrates and reveal more mechanistic details.
Zhu, Yingchuan, "Aerobic, copper catalyzed phenol methylation via the Chan-Lam coupling reaction" (2017). Honors Project, Smith College, Northampton, MA.
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