Efficient Synthesis of Novel Plasticizers by Direct Palladium-Catalyzed Di- or Multi-carbonylations

Diesters are of fundamental importance in the chemical industry and are used for many applications, e.g. as plasticizers, surfactants, emulsifiers, and lubricants. Herein, we present a straightforward and efficient method for the selective synthesis of diesters via palladium-catalyzed direct carbonylation of di- or polyols with readily available alkenes. Key-to-success is the use of a specific palladium catalyst with the "built-in-base" ligand L16 providing esterification of all alcohols and a high n/iso ratio. The synthesized diesters were evaluated as potential plasticizers in PVC films by measuring the glass transition temperature (T_g ) via differential scanning calorimetry (DSC).

Ionic Liquids: Environment-Friendly Greener Solvents for Organic Synthesis

Constituted by ions, ionic liquids (ILs) are evolving as greener solvents for many organic syntheses. Due to their high solvent power and low volatility, ionic liquids are serving as an environment-friendly substitute to conventional volatile organic solvents. The present review introduces ionic liquids as an insight into the diverse recent applications of ILs in organic synthesis.

The Palladium-Catalyzed Carbonylative Telomerization Reaction with Phenols, Polyphenols and Kraft Lignin

An efficient carbonylative coupling reaction of two equivalents of 1,3-butadiene, yielding aryl nona-3,8-dienoate esters, is performed with phenols as nucleophile, and promoted by palladium-based catalysts. Optimization study reveals the key role of benzoic acid as a cocatalyst. The suggested catalyst combination enables the conversion of a wide scope of variously substituted phenols into corresponding esters with a high yield. Further tests were performed with diphenols, naturally-occurring phenols and an industrial grade Kraft lignin, thus, indicating the scope of this reaction for transforming industrially relevant polyphenolic structures.

Biphasic Palladium-Catalyzed Hydroesterification in a Polyol Phase: Selective Synthesis of Derived Monoesters

The palladium-catalyzed hydroesterification reaction was performed with polyols and olefins in a liquid/liquid biphasic system composed of unreacted polyol on the one hand and apolar reaction products/organic solvents on the other hand. The palladium-based catalyst was immobilized in the polyol phase thanks to the use of cationic triarylphosphines possessing pendent protonated amino groups in the acidic reaction medium or to the sulfonated phosphine TPPTS (trisodium triphenylphosphine-3,3',3''-trisulfonate). Owing to the insolubility of the products in the catalytic phase, this approach allowed the synthesis of monoesters of polyols with high selectivities as well as the easy separation of the catalyst through simple decantation.

Synthesis of 1,4:3,6-dianhydrohexitols diesters from the palladium-catalyzed hydroesterification reaction

The hydroesterification of alpha olefins has been used to synthesize diesters from bio-based secondary diols: isosorbide, isomannide, and isoidide. The reaction was promoted by 0.2% palladium catalyst generated in situ from palladium acetate/triphenylphosphine/para-toluene sulfonic acid. Optimized reaction conditions allowed the selective synthesis of the diesters with high yields and the reaction conditions could be scaled up to the synthesis of hundred grams of diesters from isosorbide and 1-octene with solvent-free conditions.