A Landscape of Lignocellulosic Biopolymer Transformations into Valuable Molecules by Heterogeneous Catalysis in C'Durable Team at IRCELYON.

This review article highlights part of the research activity of the C'Durable team at IRCELYON in the field of sustainable chemistry. This review presents a landscape of the work performed on the valorization of lignocellulosic biopolymers. These studies intend to transform cellulose, hemicellulose and lignin into valuable molecules. The methodology usually consists in evaluating the behavior of the biopolymers in the absence of catalyst under various conditions (solvent, temperature), and then to assess the influence of a catalyst, most often a heterogeneous catalyst, on the reactivity. The most significant results obtained on the upgrading of cellulose and lignin, which have been mainly investigated in the team, will be presented with an opening on studies involving raw lignocellulose.

Progress in palladium-based catalytic systems for the sustainable synthesis of annulated heterocycles: a focus on indole backbones.

A survey highlighting the most recent palladium catalytic systems produced and their performances for progress in direct synthesis of indole backbones by heterocarbocyclization of reactive substrates is provided. The discussion is developed in relation with the principles of sustainable chemistry concerning atom and mass economy. In this respect, the general convergent character of the syntheses is of particular interest (one-pot, domino, cascade or tandem reactions), and the substrates accessibility and reactivity, together with the final waste production, are also important. This critical review clearly indicates that the development of ligand chemistry, mainly phosphines and carbenes, in the last few decades gave a significant impetus to powerful functionalization of indoles at virtually all positions of this ubiquitous backbone (118 references).

Recent advances in the synthesis of N-containing heteroaromatics via heterogeneously transition metal catalysed cross-coupling reactions.

N-containing heteroaromatics are important substructures found in numerous natural or synthetic alkaloids. The diversity of the structures encountered, as well as their biological and pharmaceutical relevance, have motivated research aimed at the development of new economical, efficient and selective synthetic strategies to access these compounds. Over more than 100 years of research, this hot topic has resulted in numerous so-called "classical synthetic methods" that have really contributed to this important area. However, when the selective synthesis of highly functional heteroaromatics like indoles, quinolones, indoxyls, etc. is considered these methods remain limited. Recently transition metal-catalysed (TM-catalysed) procedures for the synthesis of such compounds and further transformations, have been developed providing increased tolerance toward functional groups and leading generally to higher reaction yields. Many of these methods have proven to be the most powerful and are currently applied in target- or diversity-oriented syntheses. This review article aims at reporting the recent developments devoted to this important area, focusing on the use of heterogeneous catalysed procedures that include either the formation of the heterocyclic ring towards the nuclei or their transformations to highly substituted compounds.

Direct synthesis of tricyclic 5H-pyrido[3,2,1-ij]quinolin-3-one by domino palladium catalyzed reaction.

Unexpectedly, the palladium catalyzed coupling reaction of acrolein with 8-bromoquinoline gave 5H-pyrido[3,2,1-ij]quinolin-3-one in a single step.