C–C cross-couplings via plant-derived biosurfactant micellar catalysis: A path toward reduced process toxicity

The use of sustainable, low-toxicity reaction media remains a major challenge in modern organic synthesis. In this paper, we report the use of Plantacare 2000 (PL-2000), a fully biodegradable biosurfactant derived from renewable plant sources, as a micellar reaction medium for palladium-catalysed cross-coupling reactions in water. Aqueous PL-2000 solutions proved effective for Suzuki–Miyaura, Cassar–Heck–Sonogashira, and Mizoroki–Heck reactions, capitalising on “in-water” chemistry and “on-water” reactivity. This resulted in good conversions (up to 99%) with various iodoarenes bearing electron-donating and electron-withdrawing substituents, heterocycles, and functionalised alkynes and alkenes. Furthermore, the reaction could be performed with low catalyst loadings and allowed for recycling in all reported examples. Green chemistry metrics, including atom economy, carbon efficiency, reaction mass efficiency, stoichiometric factor, and E-factor, were calculated and compared with literature procedures. Environmental toxicity parameters (Log Koc, bioconcentration factor (BCF), bioaccumulation factor (BAF), and volatilisation potential) were also determined in-silico. These findings demonstrate that PL-2000-based synthetic protocols offer superior or comparable sustainability profiles, with reduced toxicity and improved biodegradability of the final waste, compared with the most common surfactant employed in micellar-catalysed cross-coupling reactions.