A study of solid base catalysis was conducted in three main categories, namely condensation reactions of primary alcohols, alkylation reactions of dihydroxybenzene and hydrogenation reactions of phenol. Ethanol was converted into 1-butanol over alkali earth metal oxides and modified MgO catalysts (1-20 % yield). The MgO catalyst exhibits the highest reaction activity and 1-butanol selectivity amongst the catalysts studied. Reaction of various possible intermediates (acetaldehyde, crotonaldehyde, crotylalcohol, butanal) and ethanol over MgO (1 bar, 450 oC) revealed that the dimerisation reaction does not proceed primarily through the aldol condensation reaction. The reaction is proposed to proceed through a mechanism, previously proposed by Yang and Meng, in which a C-H bond in the -position in ethanol is activated by the basic metal oxide, and condenses with another molecule of ethanol, by dehydration to form 1-butanol. iv A self-condensation reaction of propanol was carried out at atmospheric pressure over MgO as catalyst. The reaction gave 2-methylpentanol and propionaldehyde as the major products. The introduction of hydrogen before and during the reaction enhanced the catalyst selectivity to 2- methylpentanol. The effect of possible reaction intermediates on the catalyst selectivity and the mechanism of the reaction were investigated over MgO and indicated the important role of hydrogen transfer in the reaction. The highest selectivity (69 %) was achieved in the presence of hydrogen at 450 oC with propanol conversion of 24 %. Condensation reactions of ethanol with butanol or propanol to higher alcohols were carried out at atmospheric pressure over various solid-base catalysts. The ability of ethanol to be activated at either the CH2 or CH3 units played a significant role in the formation of a wide range of long chain alcohols. The major products observed during the reaction between ethanol and butanol were 2-ethylbutanol, 1-hexanol and to a lesser extent 2-ethyhexanol. The main products in the reaction of ethanol and propanol were 2-methylbutanol, 1-pentanol and butanol. Trace amounts of 2- methylpentanol were also observed. The vapour phase alkylation of catechol over supported cesium catalysts gave good selectivity to guaiacol formation. The TPD studies of the catalysts used indicated that the results can be correlated with the presence of weak basic sites on the catalyst. The gas phase selective hydrogenation of phenol to cyclohexanone was investigated over palladium supported catalysts in order to clarify the influence of the support on products distribution. High selectivities towards cyclohexanone (about 86 %) were observed on palladium supported on high surface area titanium oxide supports. On the basis of the TPD studies, it has been suggested that the basic properties of the support strongly influence the adsorption-desorption of phenol and products, and are therefore responsible for the selectivity towards the reaction products

L’utilisation de matières premières renouvelables pour la production de produits chimiques est un enjeu majeur de l’industrie chimique. Elle vise à répondre aux contraintes environnementales et économiques de disponibilité des ressources fossiles et de limitation de l’empreinte carbone des produits chimiques. Il existe une famille de molécules fonctionnelles directement issues de la biomasse dénommées « molécules plateforme ». Parmi elles, le 5-hydroxyméthylfurfural (HMF), porteur d’une fonction aldéhyde, un motif furanique et un groupe CH2OH, est particulièrement intéressante. Cependant, sa stabilité modérée, notamment en conditions acides, est une forte limitation de sa chimie et son utilisation vers des cibles en chimie fine reste un défi. Les réactions multi-composantes conduisent à des architectures élaborées à partir de briques simples de manière économe en temps et nombre d’étapes. Beaucoup de ces réactions concernent la fonction aldéhyde, ce qui rend intéressant de les appliquer au 5-HMF. Ceci est l’objet de cette thèse, qui porte sur deux réactions en particulier, Biginelli et Kabachnik-Fields. La réaction de Biginelli est la condensation d’un aldéhyde, un composé dicarbonylé et une urée conduisant à des dihydropyrimidinones (DHPMs). Etant acido-catalysée, il a été nécessaire d’optimiser les conditions pour l’appliquer au HMF. Les meilleures conditions (réaction sans solvant, ZnCl2) ont permis d’atteindre une large variété de nouvelles DHPMs dans des rendements convenables à très bons. La réaction de Kabachnik-Fields est la condensation d’un aldéhyde avec une amine et un dialkyl phosphate, conduisant à des a-aminophosphonates. Les conditions optimales trouvées pour son application au 5-HMF sont l’utilisation d’iode comme catalyseur dans le solvant biosourcé 2-MeTHF à température ambiante ou modérément élevée. Une série de nouveaux a-aminophosphonates comportant le motif HMF a été préparé. Le groupe hydroxyméthyle issu du HMF persiste dans le produit, offrant de nombreuses possibilités de dérivation et démontrant son utilité comparativement à la chimie du furfural. / Recently, the production of chemicals, either bulk or fine chemicals, from renewable biomass has attracted growing interests due to the dwindling reserve of fossil resources and the increasing awareness of environmental concerns. Some chemicals with a structure able to generate a number of derivatives, and able to be directly produced from biomass, are referred to as bio-based “platform chemicals”, and constitute the bridge between biomass and down-stream chemicals. Among these chemicals, 5-hydroxymethylfurfural (HMF), bearing an aldehyde group, a hydroxymethyl group, and a furan moiety, is the most popular one. However, its limited stability obstructs its applications in organic synthesis. Thus, developing mild and efficient synthetic routes towards existing or novel fine chemicals from HMF is still a challenging task. Multicomponent reactions (MCRs) are powerful synthetic tools allowing the straightforward formation of elaborated molecules from simple starting materials in a time- and step-saving manner. Among MCRs, many involve the aldehyde as one of the reactive components, making HMF as a potential interesting substrate in such strategies. This thesis aims at exploring the use of HMF in MCRs to provide novel fine chemicals, focusing on two reactions, namely the Biginelli and Kabachnik-Fields reactions. The Biginelli reaction is a condensation of an aldehyde, a dicarbonyl compound and urea. Although it is an old reaction, it is still showing thriving vitality, as many of its products, namely dihydropyrimidinones, exhibit various biological properties. We have investigated the reaction by choosing proper conditions to adapt to HMF, notably with respect to acidic conditions. The best conditions found for the reaction are the use of ZnCl2 as a mild Lewis acid catalyst without any solvent, giving access to new dihydropyrimidinones in modest to good yields. The Kabachnik-Fields reaction is a one-pot condensation of aldehydes, amines and dialkyl phosphites, and is considered as the most efficient and convenient approach to a-aminophosphonates. For the specific case of HMF, we could establish that the best conditions were the use of iodine as a catalyst in the bio-based solvent 2-MeTHF and room or moderately elevated temperature. Using these optimized conditions, a wide range of HMF-based a-aminophosphonates were prepared in modest to excellent yields. The hydroxymethyl group persisting in HMF-based a-aminophosphonates offers the possibilities of further modification and derivatization, illustrating the benefit of HMF as compared to furfural, for accessing a wider scope of chemical structures.