Abstract
Catechol chemistry is used as a crosslinking tool abundantly in both natural organisms (e.g. mussels, sandcastle worms) and synthetic systems to achieve the desired mechanical properties. Despite this abundance and success, the crosslinking chemistry is still poorly understood. In this study, to simplify the system, yet to capture the essential chemistry, model compounds 4-methyl catechol and propylamine are used. The reaction of 4-methyl catechol (2 mM) with propylamine (6 mM) is carried out in the presence of NaIO4 (2 mM) in 10 mM Na2CO3 aqueous solution. A variety of spectroscopic/spectrometric and chromatographic methods such as 1H NMR, LC-MS, and UV-VIS are used to track the reaction and identify the products/intermediates. It is found that the crosslinking chemistry of a catechol and an amine is both fast and complicated. Within five minutes, more than 60 products are formed. These products encompass 19 different masses ranging from molecular weight of 179 to 704. By combining time-dependent data, it is inferred that the dominant reaction pathways: the majority is formed via aryloxyl-phenol coupling and Michael-type addition, whereas a small fraction of products is formed via Schiff base reactions.
Highlights
Catecholic compounds are widely distributed among natural animal and plant systems[1,2,3]
The reaction between catechols and amines is of vital importance in natural biological processes, such as the crosslinking of adhesive proteins by marine organisms[5], the formation of cytoskeleton by insects[6] and the biosynthesis of melanin[7]
In blue mussels, both DOPA and L-lysine are present in large quantities in mussel adhesive foot proteins[8]
Summary
Catecholic compounds are widely distributed among natural animal and plant systems[1,2,3]. A well-known nucleophile is the amine that may react with o-quinones to form adducts either by Michael addition or Schiff base reaction (Fig 1)[4]. Addition of NaIO4 has significantly increased the reaction rate of catechol oxidation/crosslinking.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
