Quantitative Methylation of Lignin Monomers Using Tetrabutylammonium Hydroxide and MeI and Applications in Organic Synthesis

Efficient O-alkylation of phenols and carboxylic
acids has essential applications in organic synthesis. A mild alkylation
method for phenolic and carboxylic OH groups is developed using alkyl
halides as alkylation reagents and tetrabutylammonium hydroxide as
a base, and lignin monomers can be fully methylated in quantitative
yields. Additionally, phenolic and carboxylic OH groups can be alkylated
by different alkyl halides in one pot in different solvent systems.