Meerwein-Ponndorf-Verley reduction in current heterogeneous catalysis research: a review

Meerwein-Ponndorf-Verley (MPV) reduction is a highly selective, heterogeneously catalyzed process for the synthesis of alcohols from aldehydes and ketones under relatively mild reaction conditions. The reduction of the carbonyl group involves the transfer of a hydrogen atom from the alcohol, which, acts as a sacrificial reducing agent. Thanks to its simplicity and high variability and applicability, MPV has remained relevant over time. Recently, MPV has even become a cornerstone of basic organic chemistry, playing a key role in several cascade reactions in biomass transformation. Yet, despite extensive research on MPV, important questions are still unanswered, such as the specific role of acid and basic sites in the overall catalytic process. Here, we review advances on MPV made in the last 15 years, focusing on the catalytic materials and their properties and addressing topics ranging from classical metal oxide catalysis to new catalytic systems tested in MPV, including the synthesis of valuable products. This review is divided into four sections, namely the (1) introduction, summarizing the typical features of MPV, (2) classical studies on MPV, highlighting carbonyl group reduction as the conventional approach to synthesizing alcohols, and (3) MPV in biomass transformation, examining new applications of MPV in cascade reactions for biomass conversion into molecular platforms, followed by (4) conclusions and future perspectives on MPV heterogeneous catalysis reduction. Overall, the state of the art on MPV underscores the utility, potential and importance of this reaction not only for classical carbonyl reduction but also for biomass transformation over a wide range of catalytic materials and with various substrates.