Catalysis Involving Fluorous Phases: Fundamentals and Directions for Greener Methodologies

Abstract

Abstract This article briefly reviews the fundamentals of fluorous chemistry, with an emphasis on aspects most relevant to catalysis. The development of “greener” fluorous solvents and ponytails (phase tags) is described. Protocols that minimize the use of fluorous solvents are emphasized. Some of these exploit the highly temperature dependent solubilites of fluorous compounds in organic solvents, which can be fine‐tuned by varying the length and number of the (CF 2 ) n segments in the ponytails. Suitably designed fluorous catalysts can thus be employed under homogeneous conditions at elevated temperatures, and recovered by solid/liquid phase separation at lower temperatures. Fluorous solid supports such as fluoropolymers and fluorous silica gel can be used to aid the recovery of small catalyst quantities, and render phase separation more efficient. The use of CO 2 pressure as a non‐thermal solubility trigger, and catalyst recovery by solid phase extraction using non‐fluorous solvents, are also detailed.