IRCELYON
Image de Laurent Djakovitch

Laurent Djakovitch

Chercheur

Numéro ORCID : 0000-0001-5084-5608


445 381 (Standard + 33 [0] 472 445 300)
P1403

Rattachements

C'Durable

Mots clés

Palladium Catalysis, Biomass Upgrading, Lignin Valorisation, Cross-coupling Reactions, One-pot synthesis, Heterogeneous Catalysis, Homogeneous Catalysis, Batch and flow reactors

Academic Formation

- 04/2005             HDR « Habilitation à diriger les recherches » (University of Lyon 1)

La catalyse hétérogène autour du palladium pour la chimie fine. Des réactions de couplages croisés à l'hydrogénation enantiosélective

Jury :

  • Dr. JUTAND Anny
  • Dr. BRUNEL Daniel
  • Prof. LEMAIRE Marc
  • Prof. ASTRUC Didier
  • Dr. BESSON Michèle
  • Mr HENRYON Vivien
  • Prof. KOEHLER Klaus

- 02/1995             PhD Thesis in Organic and Organometallic Chemistry (University of Bordeaux I) : mention "Très Honorable".

L'activation des arènes par le greffon CpFe+ : synthèse d'arbres moléculaires réservoirs polyélectroniques

Jury :

  • Prof. MATHEY François
  • Prof. OSBORN John A.
  • Prof. PEREYRE Michel
  • Dr. MOULINES Françoise
  • Mr GILBERT Laurent
  • Prof. ASTRUC Didier

- 06/1990         « Diplôme d'études approfondies » in Organic Chemistry (Université de Bordeaux I) : Major, mention : "Très Bien".

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Professional Career

10/2012 -  now                         

Directeur de Recherches 2nde Classe. IRCELYON

10/2001 - 09/2012             

Chargé de Recherche 1ère Classe. IRCELYON

02/2001 - 09/2001            

IRC – UPR CNRS 5401

Study on hydrogenolysis of polyols (Rhodia, Dr. P. GALLEZOT)

08/1999 - 01/2001             

LCOMS – UMR CPE-CNRS 9986

Preparation of new heterogeneous catalysts for olefin epoxidation (Shell, Dr. J.-M. BASSET)

07/1995 - 06/1999             

TUM, Technical University of Munich, Inorganic Chemistry Department (DE)

Palladium zeolite catalysts for fine chemical syntheses (EU Marie-Curie, Prof. Dr. K. KÖHLER)

Synthesis and reactivity of new niobiocenes (Foundation Alexander von Humboldt, Prof. Drs.W. A. HERRMANN)

02/1993 - 05/1994             

University of Cambridge (GB), University Chemical Laboratories.

Studies towards the synthesis of medium sized spiro‑heterocycle compounds using phenylthio migration. (Rhône-Poulenc, Dr. S. WARREN)

09/1990 - 02/1995             

LCOO – UMR Université de Bordeaux I-CNRS 5802

L'activation des arènes par le greffon CpFe+ : synthèse d'arbres moléculaires réservoirs polyélectroniques. N° d'ordre 1210. (Rhône-Poulenc, Prof. D. ASTRUC)

Biography

Laurent DJAKOVITCH joined IRCELYON in 2001 as CNRS researcher working on the one-pot synthesis of fine chemicals by multi-functional homogenous/heterogeneous palladium catalysis, including grafted complexes on metal-oxides and metal nanoparticles, and on biomass upgrading, particularly lignin, fatty acids/esters and glycerol. He gained international recognition in these areas. He has given several communications at international congresses and various lectures at universities. He was co-leader of BIOVERT Team from 2011 to 2014.

Before this period, after a sixteen-month research period at the University of Cambridge with Dr. S. Warren (1992), Laurent Djakovitch received his PhD from the University of Bordeaux in 1995 under the direction of Prof. D. Astruc. In the following years, he joined the Technical University of Munich for 4 years working as a Alexander von Humboldt post-doc fellow with Prof. Drs. W. A. Herrmann (1995) and as a Marie-Curie fellow with Prof. Dr. K. Köhler (1997). In 1999 he returned at the University of Lyon in France, first as a research assistant in the group of Prof. J.-M. Basset before joining the CNRS.

Laurent DJAKOVITCH was coordinator of various research projects (ANR, Région Rhône-Alpes, CEDRE...) and was the French scientific co-director of GDRI action “Green synthesis of valuable chemicals from soluble lignin with the use of solid catalysts” with Russia.

He has supervised several PhD students and post-doctoral researchers, who after their training have found permanent or contractual positions. LD supervised as well various trainees (DUT, MASTER students…).

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Awards

1990: Fellow of the Rhône-Poulenc Foundation “Training through Research” (52 months)

1995: Fellow of the Alexander von Humboldt Foundation (22 months)

1997: Fellow of the European Marie-Curie Program (24 months)

Palladium Catalysis

We particularly developed supported palladium on microporous zeolites, mesoporous silica or carbons for catalytic applications. Most of them are applied to fine chemical syntheses involving several Pd-catalyzed cross-coupling reactions. Most recent applications include the one-pot syntheses of bio-active molecules.

Our studies particularly focus on the comprehensiveness of the real occurring mechanisms when applying such heterogeneous materials in solution: today almost all contributors agree with the fact that these Pd-supported materials act only as sources of Pd-species in solution to generate highly active "homogeneous-like" species through the so-called "dissolution-redeposition mechanism".

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Lignin Upgrading

Lignin, constituted of aromatic units linked through a variety of bonds, each having a special reactivity, is the second biopolymer constituting lignocellulose. Its selective transformation represents a great challenge stimulating numerous researches.

We evaluate currently several approaches to transform selectively lignin to high added –value aromatic molecules, focusing mainly on phenols and aromatic aldehydes.  

Our first approach concerned lignin transformation under inert atmosphere, delivering mainly phenols. Current researches focus mainly on the aerobic alkaline lignin depolymerisation under air to focus on aromatic aldehyde production, mainly vanillin.

Batch and continuous flow reactors are employed.

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Biosourced Materials

In the field of biosourced material, we particularly investigated the modification of biopolymers by palladium-catalyzed telomerization.

We were one of the first group describing the modification of two largely available biopolymers, chitosan and a guar hemicellulose, using the Pd-catalyzed telomerization reaction with butadiene in green media like water or iso-propanol. This reaction formed new biosourced materials by grafting a long hydrocarbon C8-chain at the surface of the biopolymers. The substitution degree (DS) could be controlled between 0.03 and 0.60 for chitosan and 0.025-0.0300 for guar. Wettability experiments indicate that new hydrophobic-hydrophilic balances were induced within the biosourced materials for highest DS. These materials can find potential applications, for example, in the field of biosourced amphiphilic materials.

Currently, we develop the transformation of technical lignin from the paper industry by the same telomerization reaction with the aim of getting new polyaromatic biosourced materials with high added-value.

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Catalyst Development

Homogeneous complexes based on palladium, copper, nickel, ruthenium… were developed working particularly on ligand architecture to improve both the catalytic activity and the stability of these materials when used in liquid phase, especially in water. Some materials include hetero-bimetallic catalysts, mainly based on palladium and copper, particularly developed for oxidative cross-coupling reactions.

Most of these complexes where then immobilized on metal oxides supports, mainly by grafting after ligand modifications, even by a “ship-in-a-bottle” like procedures when using microporous supports like zeolites.

Next, our research area linked to catalysts engineering include as well metal-based heterogeneous catalysts where particles are supported on metal oxides. Methodologies include various impregnations procedures and thermal treatments. Alternatively, as we investigate, as well, the preparation of polymer-stabilized metallic nanoparticles as catalysts, we also developed procedures for immobilizing preformed metallic nanoparticles on metal oxides supports.

All these catalytic materials were characterized by complementary techniques available at IRCELYON, before being evaluated in many reactions from organic synthesis through cross-coupling reactions and multicomponent one-pot synthesis of bioactive molecules to biomass upgrading, particularly from Kraft lignin to phenols, focusing on vanillin.

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Catalysis in Batch Reactors

Batch reactor including those under atmospheric pressure (10-250 mL) or up to 200 bar (50-300 mL), are used to evaluate catalytic properties of developed materials: active metal oxide phases, supported metals, supported metal oxide/support, grafted catalysts, or even homogeneous catalysts and metallic nanoparticles.

They are particularly well adapted for studying all catalytic organic reactions (cross-coupling reactions, one-pot synthesis, aminations…), and for those operating under pressure, lignin transformation to aromatic compounds and biopolymer grafting delivering new biosourced materials (telomerisation, esterification...).

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Catalysis in Continuous Flow Reactors

Continuous reactors consist in fixed-bed units and in a high-pressure continuous two-phase flow microreactor.

A trickle-bed continuous reactor consist in a micro-pilot SOTELEM RT 8008 entirely made from stainless steel (316L). Liquid feed is delivered inside the tubular reactor (60 mL, 33 cm length) by a diaphragm-metering pump (Pulsafeeder 680E) controlled with a frequency inverter (FMV 1105 Leroy Isomer 0-5 Hz) in a flow range of 10-800 mL.h-1. A mass flow controller delivers a constant gas flow (nitrogen, air) in the reactor up to 100 bar. Temperature range is about 50-250°C. It is used particularly for exploring biomass upgrading to chemicals, and mainly involved for developing lignin transformation to aromatic compounds under aerobic alkaline oxidative conditions when using heterogeneous catalysts.

Another smaller unit (tubular reactor 20 mL, 15 cm length) allows rapid screening of catalysts families.

Last reactor is a high-pressure continuous two-phase flow stainless steel microreactor (15 or 25 m) operating between 50-250°C, 30-100 bar (air or nitrogen) for evaluating biomass transformations to chemicals with soluble homogeneous catalysts or stabilized metal nanoparticle catalysts.

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Financial Supports

Associated Research Projects:

  • CATHECLOSM (ANR)
  • One-pot multistep synthesis, Post-doctorate project (CNRS)
  • CIBLE (ARA)
  • CATAQ (ANR)
  • GALAC (ANR)
  • CLUSTER CHIMIE (ARA)
  • CHEMLIVAL (ANR)
  • HUMEWERE (FUI)
  • PHENOLIQ (ANR)
  • COUPARC (ICL)
  • NANOTRAP (ANR)
  • HYPERCAT (ANR)

 

Authors or co-authors of 122 peer-reviewed articles, 3 book chapters, 2 patents and several communications (on November 2021).

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Palladium catalysis

Development of homogeneous and heterogeneous palladium catalysts for cross-coupling reactions as Heck, Suzuki and Sonogashira reactions.

Extension of the field to the one-pot synthesis of bioactive compounds like indoles, bibenzyles and bis-bibenzyles.

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Alkaline aerobic lignin depolymerisation

Studies and development of procedures for the alkaline aerobic lignin depolymerisation towards aromatic compounds for organic synthesis. Focus on vanillin production from spruce-pine Kraft lignin.

Methodologies involve reactions in batch and continuous reactors, like trickle-bed and two-flow reactors.

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Skills

  • Organic and Organometallic Chemistry
  • Preparations, characterizations and implementation of catalysts (homogeneous, heterogeneous -grafted or supported metals-, metal nanoparticles) in liquid phase reactions
  • Lignin characterization and transformation to high added-value molecules
  • Reactivity in liquid phase in batch (1-200 bar) or continuous reactors (three-phase trickle-bed reactor up to 150 bar; two phase flow reactor up to 100 bar. Include organic chemistry and biomass uprading
  • Chitosan and lignin upgrading to new biosourced materials