Bioinspired Functional Catechol Derivatives through Simple Thiol Conjugate Addition

Abstract

The combination of the surface-adhesive properties of catechol rings and functional moieties conveyings pecific properties is very appealing to materials chemistry,b ut the preparation of catechol derivatives often requires elaborate synthetic routes to circumventt he intrinsic reactivity of the catechol ring. In this work, functional catechols are synthesized straightforwardly by using the bioinspired reaction of several functionalt hiols with o-benzoquinone. With one exception,t he conjugated addition of the thiol takes place regioselectively at the 3-positiono ft he quinone, and is rationalized by DFT calculations. Overall, this synthetic methodology provides ag eneral and straightforward access to functional andc hain-extended catechold erivatives, which are later tested with regard to their hydro-/oleophobicity, colloidal stability, fluorescence, and metal-coordinatingc apabilities in proof-of-concept applications.Supporting information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.

Thiol-yne click reaction: an interesting way to derive thiol-provided catechols

“…25 Accordingly, some members of our group recently reported a systematic and straightforward methodology for the synthesis of functional catechols with thiol pendant groups, obtained by oxidation of the simplest catechol (pyrocatechol) to the corresponding o-quinone, followed by the conjugated nucleophilic addition of different dithiol molecules. 26,27 Although there are several examples of methodologies with catechol derivatives where the thiol-ene reaction has been exploited, the thiol-yne reaction in the presence of catechol moiety has been less explored. To the best of our knowledge, only two very interesting examples related to this issue have been published.…”

Melanin Biopolymers: Tailoring Chemical Complexity for Materials Design

“…Relevant examples include the development of adhesive and photoresponsive materials for hybrid photocapacitive sensors based on the oxidation of 5‐ S ‐cysteinyldopamine, and of artificial pheomelanin nanoparticles . Functional catechols synthesized straightforwardly by conjugation of thiols with o ‐benzoquinones can be exploited to prepare functional and chain‐extended derivatives, that can be tested for their hydro‐/oleophobicity, colloidal stability, fluorescence, and metal‐coordinating capabilities …”

“…[89] Functional catechols synthesized straightforwardly by conjugation of thiols with o-benzoquinones can be exploited to prepare functional and chain-extended derivatives,that can be tested for their hydro-/oleophobicity,c olloidal stability,f luorescence,a nd metal-coordinating capabilities. [90] Further opportunities may derive by the clever use of melanin-containing hybrid systems based on for example, nanostructures,s ilica, halloysite,a nd zeolites. [91][92][93][94][95] Notably, PDAc an be exploited as am ultifunctional melanin-type system serving as an anoscale spacer to afford controllable nanogap sizes,ar edox-active coating to promote metal shell growth, or generating reactive oxygen species for antimicrobial applications, [96] as well as ar eactive scaffold to lock molecular probes inside the nanogap.…”

Polyfunctional Sterically Hindered Catechols with Additional Phenolic Group and Their Triphenylantimony(V) Catecholates: Synthesis, Structure, and Redox Properties

“…S-functionalization of 3,5-di-tert-butyl-o-benzoquinone with cystamine and cysteine has made it possible to obtain Cu(II), Zn(II), and Ni(II) complexes [41,42]. A similar reaction with dithiols makes it possible to synthesize catechols with a free thio group or bis-catechol thioethers [43,44], which have chelating properties and the ability to be absorbed on the surface [45][46][47]. Variation of the organic groups in thiols allows one to obtain a wide range of thiolated catechols, which exhibit antioxidant, antiradical, and cryoprotective activity [48][49][50].…”