RESUMO
Biobased 5-(chloromethyl)furoate and 5-methylfuroate esters can be deprotonated to function as furylogous lithium enolates, and the former can also undergo zinc insertion to access Reformatsky-type chemistry. Carbon nucleophilicity represents hitherto little-explored reactivity in these key carbohydrate-derived platform molecules, expanding their synthetic utility and potentially opening up new sustainable product markets (e. g., in epoxy resins or biobased dyes).
RESUMO
The dye and pigment manufacturing industry is one of the most polluting in the world. Each year, over one million tons of petrochemical colorants are produced globally, the synthesis of which generates a large amount of waste. Naturally occurring, plant-based dyes, on the other hand, are resource intensive to produce (land, water, energy), and are generally less effective as colorants. Between these two extremes would be synthetic dyes that are fully sourced from biomass-derived intermediates. The present work describes the synthesis of such compounds, containing strong chromophores that lead to bright colors in the yellow to red region of the visible spectrum. The study was originally motivated by an early report of an unidentified halomethylfurfural derivative which resulted from hydrolysis in the presence of barium carbonate, now characterized as a butenolide of 5-(hydroxymethyl)furfural (HMF). The method has been generalized for the synthesis of dyes from other biobased platform molecules, and a mechanism is proposed.
