Ruthenium-catalysed isomerisation-methylenation of allyl alcohols with methanol: a one-pot synthesis of substituted pyridines.

A simple bench-stable ruthenium complex facilitates the synthesis of tetra-substituted pyridines in one pot via isomerisation-methylenation of allyl alcohol using methanol as a C1 source. This methodology is applicable to a broad range of electronically diverse diaryl and monoaryl allyl alcohols, making it highly robust for synthesising substituted pyridines. Mechanistic investigations, including control experiments and isotope labelling studies, demonstrate the involvement of metal hydride species in the isomerisation-methylenation of allyl alcohol. Additionally, many of the tetra-substituted pyridines synthesised using this methodology exhibited good photophysical properties, illustrating its potential to generate interesting materials with applicability in organic electronics.