Recent Advances in Methylation: A Guide for Selecting Methylation Reagents

Abstract Methylation is a well‐known structural modification in organic and medicinal chemistry. This review summarizes recent advances in methylation by categorizing specific methylation reagents. The challenges of mono N‐methylation of aliphatic amines and N‐methylation of peptides are discussed. This review will be useful for chemists wanting to select the appropriate reagents for methylation chemistry. Based on the large diversity of methylation reagents and their wide scope, this review also broadens perspectives on which strategies to select for utilizing a particular methylation, resulting in an increased flexibility in synthetic route planning.