Environmentally Friendly Solvent‐ and Water‐Based Coatings for Mitigation of Crystallization Fouling

The surface properties of solvent‐based (SB) and water‐based (WB) coatings and their impact on fouling during convective heat transfer of CaSO₄ solutions were investigated. Experiments demonstrated that the SB coatings had generally better non‐adhesive characteristics, especially at higher values of the electron donor component since the deposits could easily be washed away. For the SB coatings, a longer induction period compared to those of untreated surfaces was observed and a significant reduction of the fouling rate could be achieved. Further analysis of surfaces revealed that SB coatings enhanced the acid‐base repulsive force and thus reduced the deposit/solid adhesion energy. For the WB coatings, the Liftshitz‐van der Waals attractive force plays a decisive role in the adhesion process due to the higher apolar component of the surface energy.     

Base‐Catalyzed Hydroamination of Olefins: An Environmentally Friendly Route to Amines

The base‐catalyzed hydroamination of olefins offers a simple and elegant access to various primary, secondary, and tertiary amines. Particular focus is placed on developments in the area of hydroamination of non‐activated olefins. Advantages and disadvantages of the methodology compared to other synthetic methods are presented. Special attention is paid to potential industrial applications of this chemistry.     

Practical Synthesis of Allylic Silanes from Allylic Esters and Carbamates by Stereoselective Copper‐Catalyzed Allylic Substitution Reactions

The first copper‐catalyzed allylic substitution reactions of allylic acetates and carbamates employing a bis(triorganosilyl)zinc reagent are reported. This novel procedure avoids the use of stoichiometric amounts of copper salts which are usually mandatory with this chemistry. Application of this methodology to standard model substrates substantiates a high diastereoselectivity for the double bond geometry (E : Z) as well as the relative configuration (syn : anti).     

Preparation of Environmentally Friendly Amino Acid‐Based Anionic Surfactants and Characterization of Their Interfacial Properties for Detergent Products Formulation

In this study, 2 types of amino acid‐based biosurfactants such as potassium cocoyl glycinate (CGK) and sodium cocoyl glycinate (CGN) were synthesized from coconut oil. Their chemical structures were identified using FT‐IR, ¹H NMR, and ¹³C NMR spectroscopies. Characterization of their interfacial properties has shown that both CGK and CGN surfactants are surface‐active and effective in reducing interfacial free energy. Washing test results indicated relatively good detergency compared with surfactants commonly employed in detergent applications. From environmental compatibility tests, both CGK and CGN are found to be readily biodegradable, nontoxic, nonirritating, and very mild. In particular, the CGK surfactant was found to be more efficient in reducing interfacial free energy since a larger number of CGK molecules are preferentially adsorbed at the air–water interface due to higher hydrophobicity and larger mobility of CGK than CGN, indicating possible uses in detergent applications.     

Gold‐ vs. Platinum‐Catalyzed Polycyclizations by O‐Acyl Migration. Solvent‐Free Reactions

Polycyclic derivatives incorporating a cyclopropyl group have been efficiently synthesized from propargyl acetates using platinum(II), gold(I) and gold(III) catalysis. These reactions which are also viable for the preparation of medium‐sized rings, proceed with a complete diastereocontrol and can also be run in neat conditions.