Interfacial Processes—The Key Steps of Phase Transfer Catalyzed Reactions

After short historical introduction, interfacial mechanism of phase transfer catalyzed (PTC) reactions of organic anions, induced by aqueous NaOH or KOH in two-phase systems is formulated. Subsequently experimental evidence that supports the interfacial deprotonation as the key initial step of these reactions is presented.

Two-Phase Dibromocyclopropanation of Unsaturated Alcohols Using Flow Chemistry

Dibromocyclopropanations are conventionally done by addition of dibromocarbene to alkenes under phase-transfer conditions in batch reactions using a strong base (50% NaOH (aq)), vigorous stirring and long reaction times. We have shown that cyclopropanation of unsaturated alcohols can be done under ambient conditions using continuous flow chemistry with 40% (w/w) NaOH (aq) as the base. The reactions were generally rapid; the yields were comparable to yields reported in the literature for the conventional batch reaction