The adhesion of some marine organisms to almost any kind of surface in wet conditions has aroused increasing interest in recent decades. Numerous fundamental studies have been performed to understand the scientific basis of this behaviour, with catechols having been found to play a key role. Several novel bio‐inspired adhesives and coatings with value‐added performances have been developed by taking advantage of the knowledge gained from these studies. To date there has been no detailed overview focusing exclusively on the complex mode of action of these materials. The aim of this Review is to present recent investigations that elucidate the origin of the strong and versatile adsorption capacities of the catechol moiety and the effects of extrinsic factors that play important roles in the overall adhesion process, such as pH value, solvent, and the presence of metal ions. The aim is to detail the chemistry behind the astonishing properties of natural and synthetic catechol‐based adhesive materials.

Die Anhaftung einiger mariner Organismen in nasser Umgebung an fast jede Art von Oberfläche hat in den letzten Jahrzehnten zunehmendes Interesse geweckt. Zahlreiche Untersuchungen wurden durchgeführt, um die Grundlage für dieses Verhalten zu verstehen. Dabei wurde festgestellt, dass Catechol eine Schlüsselrolle spielt. Mithilfe des Wissens aus diesen Studien wurden einige neuartige bioinspirierte Klebstoffe und Beschichtungen mit zusätzlichem Nutzen entwickelt. Bisher gab es noch keine detaillierte Zusammenstellung, die sich ausschließlich auf die komplexe innere Funktionsweise dieser Materialien konzentrierte. Dieser Aufsatz befasst sich daher mit aktuellen Untersuchungen, die den Ursprung der Adsorptionskapazität von Catechol‐Derivaten und die Effekte von äußeren Faktoren aufklären, die wichtige Rollen im Gesamtprozess der Adhäsion spielen, z. B pH‐Wert, Lösungsmittel und Metallionen. Er beleuchtet die Details der Chemie, die für die erstaunlichen Eigenschaften Catechol‐haltiger adhäsiver Materialien verantwortlich sind.

The control of surface wettability with polyphenol coatings has been at the forefront of materials research since the late 1990s, when robust underwater adhesion was linked to the presence of L-DOPA—a catecholic amino acid—in unusually high amounts, in the sequences of several mussel foot proteins. Since then, several successful approaches have been reported, although a common undesired feature of most of them is the presence of a remnant color and/or the intrinsic difficulty in fine-tuning and controlling the hydrophobic character. We report here a new family of functional catechol-based coatings, grounded in the oxidative condensation of readily available pyrocatechol and thiol-capped functional moieties. The presence of at least two additional thiol groups in their structure allows for polymerization through the formation of disulfide bonds. The synthetic flexibility, together with its modular character, allowed us to: (I) develop coatings with applications exemplified by textiles for oil-spill water treatment; (II) develop multifunctional coatings, and (III) fine-tune the WCA for flat and textile surfaces. All of this was achieved with the application of colorless coatings.

Our study unveils an innovative methodology that merges catechols with mono- and disaccharides, yielding a diverse array of compounds. This strategic fusion achieves robust yields and introduces ligands with a dual nature: encompassing both the chelating attributes of catechols and the recognition capabilities of carbohydrates. This synergistic design led us to couple one of the novel ligands with an Fe(III) salt, resulting in the creation of Coordination Glycopolymer Particles (CGPs). These CGPs demonstrate remarkable qualities, boasting outstanding dispersion in both aqueous media and Phosphate Buffered Saline (PBS) solution (pH ∼7.4) at higher concentrations (0.26 mg μL⁻¹). Displaying an average Z-size of approximately 55 nm and favourable polydispersity indices (<0.25), these particles exhibit exceptional stability, maintaining their integrity over prolonged periods and temperature variations. Notably, they retain their superior dispersion and stability even when subjected to freezing or heating to 40 °C, making them exceptionally viable for driving biological assays. In contrast to established methods for synthesizing grafted glycopolymers, where typically a glycopolymer is doped with catechol derivatives to create synergy between chelating properties and those inherent to the saccharide, our approach provides a more efficient and versatile pathway for generating CGPs. This involves combining catechols and carbohydrates within a single molecule, enabling the fine-tuning of organic structure from a monomer design step and subsequently transferring these properties to the polymer.

The copper-catalyzed regioselective intermolecular hydroamination of terminal alkynes with amines was accomplished. The reaction was catalyzed by copper nanoparticles supported on montmorillonite K10 (CuNPs/MK10) and afforded the desired imines in good conversions. Then, imines were transformed into the corresponding amines after treatment with NaBH₃CN. The catalyst could be recovered and reutilized in several cycles.