Glyoxylic Acid in Morita-Baylis-Hillman Reactions: One-step Connection of a Polar C2 Fragment for Surfactant Design

The use of glyoxylic acid (GA) in Morita-Baylis-Hillman (MBH) reactions with alkyl acrylates was investigated with the aim of designing original amphiphilic compounds. The optimized reaction conditions using either DABCO or 3-hydroxyquinuclidine in ethanol resulted in good to excellent yields of MBH adducts by reacting the commercial GA aqueous solution with medium to long alkyl chain acrylates. The structural characterization confirmed the successful formation of well-defined amphiphilic architectures. Preliminary investigations of their behavior in aqueous media revealed that nonionic GAO amphiphiles effectively reduce surface tension, although their high Krafft temperatures (T_k > 85 °C) limit their solubility at ambient temperature. The introduction of ionic functionality, as in GAO8Na, resulted in improved water solubility with a significantly lower Krafft temperature (T_k < 5 °C) and a higher critical micelle concentration (CMC) than its nonionic counterpart. The hydrophilic-lipophilic balance, evaluated using the PIT-slope method, suggests that GAOn compounds exhibit a predominantly lipophilic character, making them promising candidates for W/O emulsification applications.