Tandem micellar catalysis and cloud point extraction process for C-S coupling reaction in water

A tandem process of micellar catalysis and cloud point extraction (CPE) is developed for copper-catalyzed Ullmann C-S coupling reactions in water. The functional nonionic surfactant, amine terminated polyether M2070, affords nano-micelle environment in the aqueous system; the latter splits to two phases above the cloud point temperature (CPT). The nature of the micellar catalysis in M2070 aqueous was investigated by DLS, EDS, XPS, IR, TEM and 1H NMR. M2070 was verified to provide nano-space for encapsulation and aggregation of the substrates. More importantly, the metallic micelle formed by M2070 chelating copper was identified. It is noteworthy that excellent productivity in pre-micellar catalysis of C-S coupling reactions was obtained with good tolerance of substrate. Finally, the water-micelle system was separated into two phases above the CPT thus to achieve the product separation. Furthermore, the M2070/water system can be recycled and reused.

Automated summary

A tandem process of micellar catalysis and cloud point extraction was developed for copper-catalyzed Ullmann C-S coupling reactions in water. The study showed that M2070 provided an excellent nano-micelle environment for encapsulation and aggregation of substrates, facilitating efficient catalysis reactions.