Frustrated Lewis Pair Catalysts for Hydrogenations: Optimisation and Reaction Engineering

Lead Research Organisation: Imperial College London
Department Name: Dept of Chemistry

Abstract

Catalytic hydrogenations represent one of the most important families of all chemical transformations, and are employed at all scales of chemical production. These catalysts, however, are predominantly based on rare, toxic, and expensive transition metals (e.g. Rh, Ru, Pd, Pt), which present particularly challenging problems during the synthesis of drug molecules that necessitates stringent and costly purification techniques. In recent years a new and exciting chemical methodology using catalysts based on inexpensive and abundant main group elements has been discovered. Known as 'frustrated Lewis pairs' (FLPs), these consist of a p-block centred Lewis acid [typically B-based e.g. B(C6F5)3] and a Lewis base which (for steric and/or electronic reasons) cannot interact strongly with one another; this leads to unquenched reactivity that can be exploited for the reaction with H2, which can subsequently be delivered to substrates via catalytic polar (H+ + H- ) hydrogenation. However, FLPs are currently less tolerant to moisture and have a slower intrinsic rate than traditional hydrogenation catalysts, hindering their industrial application. This project aims to understand and improve the catalytic performance and industrial scalability of FLP-based hydrogenations to provide a practical alternative to transition metal-based catalysts. To achieve these goals, the project will involve close collaboration between the Depts of Chemistry and Chemical Engineering, using a high pressure stirred reactor to measure the intrinsic reaction kinetics. These results will underpin a rational approach to catalyst modification, optimisation and scale-up of these processes.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S023232/1 01/04/2019 30/09/2027
2279884 Studentship EP/S023232/1 01/10/2019 31/12/2023 Ben Michael John Lancaster