Julien Roger

Julien Roger
University of Burgundy | UB · Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB)

Doctor

About

87
Publications
6,117
Reads
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2,354
Citations
Introduction
Since 2013, I currently work at the Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), University of Burgundy as assistant professor. My current research interests focus on the C-H bond activation for new C-Heteroatom bond formation and mechanism understanding.
Additional affiliations
September 2013 - present
University of Burgundy
Position
  • Professor (Assistant)
September 2012 - August 2013
University of Burgundy
Position
  • Post-doctoral
December 2010 - February 2012
Nagoya University
Position
  • Post-doctoral

Publications

Publications (87)
Article
In comparison to mononuclear gold Lewis‐acid catalysts, digold complexes and dual‐gold catalysis have illustrated a distinct and powerful potential for the activation of carbon‐carbon multiple bonds. Herein, we pushed this concept further by designing novel tetranuclear gold(I) dicationic complexes structurally supported by strongly stabilizing con...
Article
Full-text available
C–H arylation of 1‐pyrenylphosphine derivatives catalyzed by rhodium and directed by a diphenylphosphino group is selectively achieved at the K‐region, i.e. 4‐, 5‐, 9‐, or 10‐position of the pyrene moiety. The functionalization at the K‐region of topical pyrene substrates is hardly accessible by conventional organic synthetic methods. This peri C–H...
Article
Dihydrogen is one of the sustainable energy vectors envisioned for the future. However, the rapidly reversible and secure storage of large quantities of hydrogen is still a technological and scientific challenge. In this context, this review proposes a recent state-of-the-art on H2 production capacities from the dehydrogenation reaction of ammonia...
Article
Full-text available
The carbon-carbon cross-coupling of phenyl s-tetrazine (Tz) units at their ortho-phenyl positions allows the formation of constrained bis(tetrazines) with original tweezer structures. In these compounds, the face-to-face positioning of the central tetrazine cores is reinforced by π-stacking of the electron-poor nitrogen-containing heteroaromatic mo...
Preprint
Full-text available
The carbon-carbon cross-coupling of phenyl s-tetrazine (Tz) units at their ortho-phenyl positions allows to form constrained bis(tetrazines) with original tweezer structures. In these compounds, the face-to-face positioning of the central tetrazine cores is endorsed by pi-staking of the electron-poor nitrogen-containing heteroaromatic moieties. The...
Article
Direct arylation of most five‐membered ring heterocycles are generally easily accessible and strongly favored at the α‐position using classical palladium‐catalysis. Conversely, regioselective functionalization of such heterocycles at the concurrent β‐position remains currently very challenging. Herein, we report general conditions for regioselectiv...
Article
Full-text available
Ultrasmall gold nanoparticles (NPs) stabilized in networks by polymantane ligands (diamondoids) were successfully used as precatalysts for highly selective heterogeneous gold-catalyzed dimethyl allyl(propargyl)malonate cyclization to 5-membered conjugated diene. Such reaction usually suffers from selectivity issues with homogeneous catalysts. This...
Article
An expedient two-steps synthesis produces in good yield polyaromatic heptacyclic (hetero)arylated o-substituted s-aryltetrazines (s-Tz) directly from diphenyl s-tetrazine. This methodology overcomes the steric limitations of classical Pinner-like syntheses encountered for o-functionalized s-Tz. A single step palladium-catalyzed N-directed C–H bond...
Article
Full-text available
Combined experiments and modelling rationalize the large influence of solvent composition on pyrrolidine nucleophilicity.
Article
In constrained di‐ tert ‐butylated‐bis(phosphino)ferrocene ligands, the phosphino substituents R ( R = phenyl, cyclohexyl, iso‐propyl, mesityl, or furyl ) induce selective formation of Au I halide complexes. Thus, dinuclear linear two‐coordinate, or rare mononuclear trigonal three‐coordinate and tetrahedral four‐coordinate complexes can be selectiv...
Article
The kinetics of the reactions of 4‐nitrobenzofurazane 1a , 4‐nitrobenzothiadiazole 1b , and 4‐nitrobenzoselenadiazole 1c with a series of 4‐Y‐substituted phenoxide anions 2a‐e (Y = OMe, Me, H, Cl, and CN) in aqueous solution at 20°C were investigated photometrically. The derived second‐order rate constants (k 2) have been combined with the nucleoph...
Article
In this work, new receptors built on the porphyrin scaffold were synthesized for halophenols recognition. A quinolyl group was introduced on the porphyrin's periphery as binding site, to form two series of molecules based on two distinct porphyrin frames and which were obtained in free base and zinc forms. The binding between these porphyrin‐based...
Article
Four free base aminoporphyrins were synthesized in two steps via regioselective anodic nucleophilic substitution with pyridine followed by ring opening of the electrogenerated pyridinium with piperidine. The X-ray crystallographic structure of the unstable 2-aminotetraphenylporphyrin was solved. Protonation of this latter compound leads to the stab...
Article
Ferrocene is unique among organometallics compounds, and serves notably as a versatile platform towards the production of ligands useful to promote transition metals chemistry. A general limiting aspect of the synthesis of ferrocene derivatives is the efficient access to sophisticated highly functionalized polysubstituted ferrocenes, i. e. bearing...
Article
Full-text available
Palladium-catalyzed oxidative C–H halogenation and acetoxylation reactions of S-unprotected sulfides, selectively directed by pyridinyl groups, allows the formation of C–X bonds (X = I, Br, Cl, OAc) by using simple halosuccinimide or phenyliodine diacetate (PIDA) oxidants. The undesired formation of sulfoxides and/or sulfones, which are usually obs...
Article
Tetrazine core “click‐chemistry” is a blooming method for bioorthogonal labeling and crosslinking. We introduce two new classes of doubly clickable s‐aryl tetrazines synthesized by Cu‐catalyzed cross‐coupling. Homocoupling arylation applied to o‐brominated s‐aryl tetrazines leads to bis‐tetrazines structurally‐characterized by tetrazine cores arran...
Article
Tetrazine core “click‐chemistry” is a blooming method for bioorthogonal labeling and crosslinking. We introduce two new classes of doubly clickable s‐aryl tetrazines synthesized by Cu‐catalyzed cross‐coupling. Homocoupling arylation applied to o‐brominated s‐aryl tetrazines leads to bis‐tetrazines structurally‐characterized by tetrazine cores arran...
Article
A new class of tritopic ferrocene-based ambiphilic compound has been prepared by assembling diphosphino- and boryl-substituted cyclopentadienides at iron. The presence of five sterically demanding substituents on the ferrocene platform...
Article
Metal-catalysed ortho-directed C–H functionalization usually faces selectivity issues in competition between mono- and disubstitued processes. We report the ruthenium-catalysed N-directed C–H monoarylation of arylpyrazoles with a selectivity up to 96...
Article
A general challenging issue in the synthesis of hemilabile ferrocene ligands is the access to highly functionalized ferrocene starting materials. These can bear donor/acceptor atoms, additional functional and structuring spectator substituents, but the preparation of such species poses general synthetic difficulties. We report herein alternative sy...
Article
Full-text available
The Cover Feature shows the “Vitruvian Man”, a drawing made by the universal genius Leonardo da Vinci around 1490. For more than five centuries the mysteries carried out by this picture have been discussed in mathematics, arts, alchemy, and philosophy. At the dawn of amazing chemical direct modifications of C–H bonds, the last decade has also seen...
Article
Palladium‐catalyzed electrophilic fluorination is a particularly attractive and challenging synthetic issue. Because of the rapid evolution of this topic, a critical point on the mechanistic and experimental advances is provided herein. In the present review we focused at current mechanistic understanding in electrophilic fluorination (and related...
Article
Aryl triflates and related phenolates are suitable electrophile coupling partners for the ruthenium‐catalyzed direct arylation of heteroaromatic substrates using azole N‐directed Csp²–H activation. We report herein convenient conditions for the efficient ortho‐C–H functionalization of aryl‐pyrazoles, thiazoles and pyridines in which [RuCl2(p‐Cym)]2...
Article
The mild (electro)chemical oxidation of pyridin-2-ylthio-meso substituted Ni(II) porphyrins affords C-N fused cationic and dicationic pyridinium-based derivatives. These porphyrins are fully characterized and the molecular structure of one of them...
Article
We provide efficient synthetic access to heteroaryl sulfones in two-steps using a simple palladium–1,1′-bis[(diphenyl)phosphanyl)]ferrocene catalyst to form in high yields highly functionalized heteroaromatic thioethers. Pyridinyl-containing substrates can be subsequently selectively oxidized into sulfones and NH-sulfoximines by using very mild oxi...
Article
We report a general route for synthesizing ortho-substituted unsymmetrical biphenyl and polyaromatic s-aryltetrazines. These compounds are inaccessible by classical Pinner hydrazine condensation or by the current s-aryltetrazine aromatic core functionalization methods described up to now. We exploited multiple versatile N-directed palladium C–H act...
Article
We report a general route for synthesizing ortho-substituted unsymmetrical biphenyl and polyaromatic s-aryltetrazines. These compounds are inaccessible by classical Pinner hydrazine condensation or by the current s-aryltetrazine aromatic core functionalization methods described up to now. We exploited multiple versatile N-directed palladium C–H act...
Article
We describe an efficient palladium-catalyzed selective C–H ortho-monohalogenation (X = I, Br, Cl, F) of various functionalized N-(2-pyridyl)arylsulfones. Ortho-, meta- and para-functionalization is tolerated at the arene group which undergoes C–H halogenation. Some modifications are also possible on the 2-(arylsulfonyl)heteroaryl directing groups....
Article
Unequally functionalized ferrocenes give access to valuable hemilabile reactivity in catalytic reaction. We address the synthesis of hybrid (P, N)-ferrocenyl compounds for which recent catalytic breakthrough applications have been reported, transversely in late transition metals chemistry. Palladium, nickel, rhodium, iridium, and emerging iron and...
Article
A general synthesis of highly functionalized ferrocenes, which includes (P, B)- and (N, B)-ambiphiles has been developed at multigram scale. Diastereoselective stepwise modification of di-tert-butylated ferrocene included the unprecedented separation of electroactive species. Bulky alkyl groups on ferrocene insure planar chirality of ambiphiles and...
Article
A method that allows hindered ortho-substituted aryl iodides to be efficiently coupled to phenylboronic acid using a gold-catalyzed C-C bond formation is presented. The use of a molecularly-defined dinuclear gold chloride catalytic precursor that is stabilized by a new tetradentate (N,N')-diamino-(P,P')-diphosphino ferrocene hybrid ligand in a Suzu...
Article
A smart steric control of the metallocene backbone in bis- and poly(phosphino)ferrocene ligands favors intramolecular aurophilic interactions between [AuCl] fragments in polynuclear gold(I) complexes. We synthesized and characterized by multinuclear NMR and X-ray diffraction analysis mono-, di-, and polynuclear gold complexes of constrained ferroce...
Article
The diastereoselective synthesis of dialkylated ferrocenyl bis(phosphane)s bearing aryl, alkyl, and hetero- or polycyclic substituents on the phosphino groups is reported, together with their characterization in the solid state by X-ray structure analysis and in solution by multinuclear NMR spectroscopy. Introduction of various alkyl groups on the...
Article
Full-text available
A general catalyzed direct C-H functionalization of s-tetrazines is reported. Under mild reaction conditions, N-directed ortho-C-H activation of tetrazines allows the introduction of various functional groups, thus forming carbon-heteroatom bonds: C-X (X=I, Br, Cl) and C-O. Based on this methodology, we developed electrophilic mono- and poly-ortho-...
Article
Palladium–polypyrrole nanocomposites (Pd@PPy) with unique combination of high palladium dispersion (nanoparticle size 2.4 nm) and high palladium content (35 wt%) are efficient catalysts for the selective arylation of substituted pyrroles and imidazoles with either activated or deactivated aryl bromides. The performances of the recoverable supported...
Patent
The present invention relates to a process for the synthesis of 3,6 functionalized 1,2,4,5-tetrazine compounds of general formula (I). 5 (I) as defined thereafter. The chemistry of s-tetrazines (1,2,4,5-tetrazines) has attracted increasing interest over the years, owing to multiple applications (biochemical, materials) in relation with their unique...
Article
Full-text available
Hexasubstituted hybrid tetradentate (N,N',P,P')-ferrocenes bearing phosphino and aminomethyl groups, plus hindering tert-butyl moieties, were synthesized by using two different strategies: a "diverging" synthesis involving successive functionalization of preformed di-tert-butylated ferrocene and a "converging" assembly of the species from appropria...
Article
Full-text available
A general protocol for palladium-catalysed CH mono- and di-fluorination of highly substituted arylpyrazoles is reported. Coupling pathways and substrate limitations are discussed in the light of complementary mechanistic experimental and density functional theory (DFT) studies. The mono- and di-ortho-fluorination of arylpyrazoles having substituted...
Article
A general alkylation of heterocycles using a simple palladium catalyst is reported. Most classes of heterocycles, including indoles and pyridines, efficiently coupled with unactivated secondary and tertiary alkyl halides. An alkyl radical addition to neutral heteroarenes is most likely involved.
Article
Full-text available
A general alkylation of heterocycles using a simple palladium catalyst is reported. Most classes of heterocycles, including indoles and pyridines, efficiently coupled with unactivated secondary and tertiary alkyl halides. An alkyl radical addition to neutral heteroarenes is most likely involved.
Article
Full-text available
The arylation of aniline derivatives with dichloroarenes under a low palladium content (below the currently used 5 to 10 mol%) was studied using nine different ferrocenylphosphine ligands, including the easily accessible 1,1'-bis(diphenylphosphino) ferrocene, DPPF. The electron-enriched air-stable tridentate ferrocenylpolyphosphine 1,2-bis(diphenyl...
Patent
Full-text available
Unsym.- substituted controlled conformation ferrocenes 1, 1'- R12- 3- R2- 3'- R3- (η5- C5H3) 2Fe (1; R1 = bulky group, preferably, trialkylmethyl, tBu, iPr, iBu; R2 = electron- donating group, Lewis base, phosphino; R3 = electron- accepting group, Lewis acid, such as boryl, borono, trifluoroborato) , useful as ligands for transition metal- catalyze...
Article
Full-text available
A variety of aminomethyl-substituted ferrocenes and the parent compounds (iminomethyl)ferrocenes, azaferrocenophanes, and diferrocenylamines can be selectively synthesized from reductive amination of 1,1′-diformylferrocene or formylferrocene. The optimized one- or two-step reactions have delivered 13 new compounds, isolated in 65–97% yields, which...
Article
Full-text available
A novel and efficient palladium-catalysed direct di-heteroarylation of 1,2-dichloroperfluorocyclopentene with a variety of heteroarenes is reported, giving rise to 1,2-di(heteroaryl)ylperfluorocyclopentene photochromic compounds. The reaction proceeds with thiazoles, thiophenes or furan derivatives and tolerates various substituents.
Article
Full-text available
The palladium-catalyzed direct arylation at C2 or C5 of free NH2 substituted thiophene derivatives was found to proceed in moderate to high yields using a variety of aryl halides. The choice of potassium acetate as the base was found to be crucial to inhibit the amination reaction and to promote the direct arylation.
Article
Full-text available
The palladium-catalysed direct arylation at C-4 of non-protected 5-aminopyrazoles was found to proceed in high yields using a variety of aryl bromides. The choice of potassium acetate as the base was found to be crucial to inhibit the amination reaction and to promote the direct arylation.
Article
Full-text available
The direct coupling of aryl halides with thiophene would be a considerable advantage for sustainable development because of only HBr associated with a base as by-product is formed and the number of steps to prepare these compounds is less than in more classical coupling reactions. We observed that through the use of only 0.2 mol% Pd(OAc)2 as the ca...
Article
Full-text available
Palladium acetate associated to potassium carbonate as catalytic system has been found to efficiently catalyse the direct 5-arylation of furans or thiophenes bearing enal, enone or acrylate functions at carbon C-2, and to inhibit the Heck-type reaction. The nature of the base is crucial to control the selectivity of the arylation. In the presence o...
Article
Full-text available
The palladium-catalyzed direct arylation of furan, thiophene, pyrrole, or pyrazole derivatives bearing CONHR substituents on C2, C3, or C5 with aryl bromides was studied. The use of KOAc as the base, DMAc as the solvent, and PdCl(C3H5)(dppb) as the catalyst was found to give regioselectively and without decarbamoylation the arylated heteroaromatics...
Article
Full-text available
The palladium catalysed 5-arylation of 2-(trimethylsilyl)thiophene with aryl bromides via C-H bond functionalisation allows the synthesis of arylated silylthiophenes in only one step.
Thesis
Thèse de Doctorat de l'Université de Rennes 1 Au cours de ce travail de thèse, nous avons sommes intéressés à l’activation/fonctionnalisation de liaisons C-H pour la formation de biaryles, qui peut se révéler être un outil intéressant d’un point de vue économique et écologique par rapport aux autres types de couplage tels que Suzuki, Stille ou Negi...
Article
Full-text available
The palladium-catalysed direct 2-, 4- or 5-arylation of a wide range of heteroaromatics with aryl halides proceed in moderate to good yields using the eco-friendly solvents carbonates. The best yields were obtained using benzoxazole or thiazole derivatives. The arylation of furan, thiophene, pyrrole, imidazole or isoxazole derivatives was found to...
Article
Full-text available
The palladium-catalyzed direct 2- or 5-arylation of some free NH2-substituted thiophene derivatives was found to proceed in high yields using a variety of aryl bromides. In the course of these reactions, no coupling of the aryl bromide with the thiophene NH2 substituent was detected. The presence of an ester substituent on C2 of thiophene was found...