METHYL ALCOHOL, HPLC

Khan, Shahriar N., et al. The Journal of Organic Chemistry 89.24 (2024): 18353-18369.

Methanol plays a critical catalytic role in the anodic electrosynthesis of enol ether cation radicals by facilitating nucleophilic alcohol trapping, a key step in intramolecular cyclization reactions. Computational studies reveal that methanol stabilizes the intermediate oxonium ion through complexation, forming a "Zundel-like" shared proton structure reminiscent of H₅O₂⁺. This proton-sharing significantly lowers the energy barrier, rendering the intramolecular alcohol attack effectively barrierless and enabling rapid cyclization.
Reaction free energy calculations indicate that the intramolecular alcohol trapping follows second-order kinetics with a first-order dependence on methanol concentration. Additionally, methanol solvent molecules participate in an analogous barrierless nucleophilic attack on the oxidized enol ether, exhibiting overall third-order kinetics due to involvement of a secondary methanol molecule in proton sharing. This catalytic mechanism underscores the critical influence of solvent environment, particularly methanol content, on reaction yield and selectivity.
The computational insights align with experimental observations where methanol concentration modulates the oxidation potential of the substrate ("Nernstian shift"), facilitating easier oxidation and efficient product formation. These findings emphasize methanol's dual function as a solvent and proton shuttle, promoting selective and efficient electrosynthesis pathways. This mechanistic understanding supports the strategic use of methanol in optimizing anodic coupling reactions involving sensitive cation radical intermediates, advancing synthetic methodologies in organic electrochemistry.

Li, Lei, et al. Applied Catalysis A: General 696 (2025): 120168.

This study investigates the role of methanol in the alkylation of phenol and the subsequent anisole rearrangement catalyzed by NaX zeolite and ion-exchange modified X zeolites (H⁺, K⁺, Cs⁺, Mg²⁺). Methanol serves as the methylating agent, initially producing O-alkylation products-primarily anisole-which act as key intermediates. These intermediates then undergo rearrangement to form C-alkylation products, such as cresols, establishing a two-step reaction pathway.
Experimental data demonstrate that on basic modified X zeolites, O-alkylation products dominate, with increasing basicity enhancing anisole selectivity. Conversely, acid zeolites favor a rapid decrease of anisole with rising temperature, shifting product distribution toward cresols. Notably, stratified mixing of CsX/HX catalysts significantly improves o-cresol selectivity while suppressing p- and m-cresol formation, supporting the sequential transformation from O-alkylation to C-alkylation products.
Temperature and zeolite acidity/basicity substantially influence methanol's methylation efficiency and product composition. The correlation between anisole conversion and phenol alkylation product distributions across modified zeolites confirms methanol's dual function as reactant and intermediate precursor provider.
This mechanistic insight emphasizes methanol's critical role in catalytic methylation reactions over zeolites, enabling controlled synthesis of valuable cresol isomers. The findings guide catalyst design for optimizing selectivity in industrial phenol alkylation processes using methanol as a methyl donor.

Luo, Jixu, et al. Bioresource Technology (2025): 132880.

Methanol, as a sustainable C1 carbon source, holds great promise for microalgal cultivation, yet its effective utilization is limited by toxicity and metabolic constraints. This study reports the development of a methanol-tolerant Graesiella emersonii mutant strain (11-3) generated through Atmospheric and Room Temperature Plasma (ARTP) mutagenesis, exhibiting a 27.1% higher methanol consumption rate than the wild-type. The mutant strain demonstrated a 60% increase in growth rate under methanol-supplemented conditions, driven by enhanced photosynthetic efficiency, nitrogen assimilation, and carbon fixation.
Biochemical analyses revealed a simultaneous 40% increase in carbohydrate and protein accumulation, alongside an enriched essential amino acid profile. Fatty acid profiling indicated increased membrane lipid unsaturation, reflecting adaptive responses to methanol stress. Moreover, the mutant showed elevated production of carotenoids, particularly astaxanthin, adding valuable pigments to its bioproduct portfolio.
The superior methanol tolerance and metabolic reprogramming of strain 11-3 highlight its potential for methanol-based microalgal biorefineries, converting industrial methanol byproducts into high-quality proteins and bioactive compounds. This work lays the groundwork for further genetic and process optimization aimed at sustainable bioresource utilization and economic valorization of methanol in microalgal biotechnology.
Future research directions include comparative genomics and transcriptomics to elucidate methanol tolerance mechanisms, targeted metabolic engineering, and scaling cultivation parameters for commercial applications.