Optimal conditions for Pt-catalyzed microfluidic synthesis of iodoolefins

Abstract

The employment of acetylene-derived alkenyl iodides facilitates the integration of olefinic moieties into intricate molecular structures. Their synthesis is often related to catalytic gas-liquid process where traditional batch methods suffer from inefficient mass transfer upon scaling, thus limiting yields of iodoolefins production. In this study, we develop microfluidic synthesis of vinyl iodide and (E,E)-1,4-diiodo-1,3-butadiene from acetylene using Pt^IV iodo complexes as a catalyst in aqueous solutions. Segmented Taylor flow regime was applied to increase interfacial surface area and subsequent gas-liquid separation enables online mass-spectroscopic conversion monitoring. We varied reaction parameters to study temperature dependence of the conversion as well as influence of gas and liquid flow rates. The optimal conditions were derived from Bayesian approach and promoted better mass transfer and, thereby, higher acetylene conversion. The methodology can be readily extended to the synthesis of other small organic iodides.