Single or double? A radical approach to frustrated Lewis pairs

Rebecca L. Melen / Cardiff University, United Kingdom

September 25, 2025

Introduction

The donor–acceptor ability of frustrated Lewis pairs (FLPs) has led to widespread applications in recent years. Recently, it was shown that single electron transfer (SET) from a Lewis base donor to a Lewis acid acceptor can produce a frustrated radical pair (FRP) species. This depends on both the substrate and energy required (photochemical or thermal) to promote an FLP into an FRP. In this lecture, we will discuss the C–C and C–S bond forming reactions using FLPs. The nature of these reaction pathways as well as their selectivity has been investigated by extensive electron paramagnetic resonance (EPR) studies, kinetic studies, and density functional theory (DFT) calculations both to elucidate the mechanism of these coupling reactions.

Rebecca L. Melen

studied for her undergraduate and PhD degrees at the University of Cambridge, completing her PhD in 2012 with Prof. Wright. Following postdoctoral studies with Prof. Stephan in Toronto and with Prof. Gade in Heidelberg, she took up a position at Cardiff University in 2014, where she is now a professor in inorganic chemistry. In 2018, she was awarded an EPSRC early career fellowship. She is the recipient of a 2022 Philip Leverhulme Prize in Chemistry, and is the 2025 winner of the RSC Sir Geoffrey Wilkinson Prize. Her research interests lie in main group chemistry and the applications of main group Lewis acids in synthesis and catalysis.