A5079552694- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Organoboron and organosilicon chemistry
- Asymmetric Synthesis and Catalysis
- Catalytic C–H Functionalization Methods
- Synthetic Organic Chemistry Methods
- Chemical Synthesis and Analysis
- Synthesis and Properties of Aromatic Compounds
- Radical Photochemical Reactions
- Cyclopropane Reaction Mechanisms
- Fluorine in Organic Chemistry
- Luminescence and Fluorescent Materials
- Advanced Synthetic Organic Chemistry
- Sulfur-Based Synthesis Techniques
- Carbohydrate Chemistry and Synthesis
- Catalytic Alkyne Reactions
- Microwave-Assisted Synthesis and Applications
- Health, Medicine and Society
- Synthesis and Reactions of Organic Compounds
- Asymmetric Hydrogenation and Catalysis
- Advanced NMR Techniques and Applications
- Analytical Chemistry and Chromatography
- Marine Sponges and Natural Products
- Cancer Treatment and Pharmacology
- Catalytic Cross-Coupling Reactions
Université de Rennes
2012-2024
Centre National de la Recherche Scientifique
2012-2024
Institut des Sciences Chimiques de Rennes
2013-2024
Université Rennes 2
2018
[3,3]-Sigmatropic cyanate–isocyanate rearrangement provides a powerful tool for the preparation of α-isocyanato allylboronic esters, which can be further trapped with variety nucleophiles. Hydrogenation gave corresponding α-aminoboronates derivatives while addition aldehydes afforded homoallylic alcohols, (tetrahydrofuran-2-yl)carbamate, ether, or urea derivatives.
Abstract A new enantiopure cyclometallated iridium complex bearing a [4]helicenic ‐coordinating and two dfppy (2‐(2,4‐difluorophenyl)‐pyridyl) ligands was prepared. This displayed long‐lived phosphorescence both in solution the solid state. Its chiroptical properties, namely electronic circular dichroism circularly polarized luminescence, were also examined. Comparison with former chiral complexes enabled assignment of Δ Ir ‐(−) Λ ‐(+) absolute configurations.
Abstract Mono‐ and di‐boranil‐substituted helicenes were prepared by BF 2 ‐borylation of the corresponding anils, readily synthesized condensation 2‐amino‐ 2,15‐diamino‐helicenes with 4‐(diethylamino)salicylaldehyde. After enantiomeric resolution using HPLC, their chiroptical properties including circularly polarized fluorescence in solution PMMA films investigated rationalized help NMR, X‐ray quantum‐chemical calculations.
An improvement in the catalytic enantioselective allylboration of isatins with 2-allyl-1,3,2-dioxaborolane presence chiral BINOL derivatives is reported, offering an efficient one-step access to enantioenriched N-unprotected 3-allyl-3-hydroxy-2-oxindoles. This process also effective for crotylboration reaction enantiomeric ratios (er) up 97:3, as well asymmetric synthesis homopropargylic alcohols via allenyl addition indoline-2,3-diones. Origins high enantioselectivity BINOL-catalyzed were...
The reactions of 1-silyl-3-boryl-2-alkenes with various electrophilic reagents (Selectfluor, N-halosuccinimides, benzhydryl, and propargylic alcohols in the presence a Lewis acid, N-alkoxycarbonyliminium ion) have been investigated as new routes to α-substituted allylboronates. Further functional transformations, including allylboration, Suzuki coupling, protodeboronation, cycloisomerization, carried out illustrate synthetic potential these γ-borylallylsilanes.
Abstract The combination of in situ generated α‐isocyanato allylboronic esters and aldehydes afforded seven‐membered‐ring enecarbamates with high levels diastereo‐ enantiocontrol. They were easily converted into diversely substituted 1,3‐oxazepan‐2‐ones. An unprecedented rearrangement 5‐acetoxy‐7‐aryl or styryl derivatives led to tetrasubstituted pyrrolidines. A computational study provides evidence on the feasibility proposed mechanism this unusual ring contraction.
A new approach based on one-pot sequential transformations with application for the first total synthesis of (−)-nicotlactone B and (−)-galbacin.
Enantiopure carbo[6]helicenyl boronates were synthesized using a photocyclization reaction as the key step. These compounds further converted to various amino derivatives copper-catalyzed azidation or amination and reductive alkylation of benzylazide by helicenyl dichloroborane. Asymmetric Petasis condensation with glyoxylic acid morpholine controlled helical chirality afforded corresponding esters.
[3,3]‐Sigmatropic rearrangements represent powerful methods in the toolbox of synthetic organic chemists for stereoselective construction carbon–carbon as well carbon–heteroatom bonds. Thus, allyl cyanate/isocyanate rearrangement, although still underused preparation allylamine derivatives, offers clear advantages over other similar methods. It usually occurs at or below ambient temperature with no need to use any metal catalyst, a stereospecific way, and complete transfer chirality....
Abstract The reaction of 1,6‐ and 1,7‐enynes, derived from carboxylic boronic amino acids, with diazo compounds in the presence (cyclooctadiene)(pentamethylcyclopentadiene)ruthenium chloride complex [RuCl(cod)(C 5 Me )] catalyst leads to formation strained bicyclic proline or homoproline derivatives good yields. This catalytic transformation proceeds under mild conditions, one step easily accessible enynes was applied various protecting groups. High stereoselectivities for created alkenyl...
A convergent and rapid synthesis of original C2,C3-unsaturated, C11,C13-keto–enol macrocycles with a peloruside skeleton has been developed. These unsaturated constitute valuable platforms to access analogues high diversity. The four-fragment strategy implemented features two aldol-type couplings the central C12–C14 building block TES-diazoacetone late-stage ring-closing metathesis. Enantiopure analogue 18ab showed antiproliferative activity in low micromolar range on NCI MCF7 tumor cell lines.
Abstract The combination of in situ generated α‐isocyanato allylboronic esters and aldehydes afforded seven‐membered‐ring enecarbamates with high levels diastereo‐ enantiocontrol. They were easily converted into diversely substituted 1,3‐oxazepan‐2‐ones. An unprecedented rearrangement 5‐acetoxy‐7‐aryl or styryl derivatives led to tetrasubstituted pyrrolidines. A computational study provides evidence on the feasibility proposed mechanism this unusual ring contraction.
Abstract A new cascade reaction to access C ‐pyrrolyl nitrones en route isoxazolidines is reported; a process that involves four successive steps, the first key step being an ene‐reaction of 3‐methyl‐1,3‐dienylboronate ester with aryl nitroso compounds derive uncommon 1,3‐dipoles which react various alkenes isoxazolidines. The scope and mechanism sequence discussed.
In this paper, a new access to several chiral 3-aminoglycals as potential precursors for glycosylated natural products is reported from common starting material, (−)-methyl-L-lactate. The stereodivergent strategy based on the implementation of ring-closing metathesis vinyl ethers key step reaction sequences developed.
4-Methylenechromanes were prepared <italic>via</italic> a three-step process from 2-borylated α-methylstyrenes using glyoxylate-ene reaction catalyzed by scandium(<sc>iii</sc>) triflate and Mitsunobu cyclization as key steps.
Allylboration reactions of ketones catalyzed by BINOL derivatives can exhibit highly variable stereochemical courses depending on the nature and reactivity ketone substrate. In this Article, we put into perspective relationship between starting material active species involved in asymmetric allyboration derivatives. This work, aimed at comparing different plausible mechanisms density functional theory (DFT) M06-2X/6-311+G(d,p) level involving types allylboronates presence organocatalyst,...
2-Amino[2.2]paracyclophane reacts with salicylaldehyde or 2-hydroxyacetophenone to yield imines that then give access a new series of boranils (8b-d) upon complexation BF2 . These novel boron-containing compounds display both planar and axial chiralities were examined experimentally computationally. In particular, their photophysical chiroptical properties studied compared newly prepared, simpler (9a-d) exhibiting chirality only. Less sophisticated chiral architectures shown demonstrate...
Abstract In a first instance, the effect of microwave irradiation on 1,3‐Dioxa‐[3,3]‐sigmatropic rearrangement aryl allylic carbamates was investigated. Under these new conditions, reaction acceleration clearly highlighted compared to conventional heating conditions. Depending electronic nature substituents aromatic group, this type can be faster with similar or improved yields. Due experimental improvement, diversity able undergo in reasonable time (30 min.) and acceptable high yields...
Pour faire face aux délais d’attente en aemo , la pjj se voit confier des mjie qui ne s’inscrivent plus seulement dans l’investigation, mais aussi l’accompagnement. Une analyse conséquences de cette inversion est proposée.
Abstract The title reaction sequence starting from carbamates (I) leads to 6,7‐dihydro‐1,3‐oxazepinones (III), which are converted into 1,3‐oxazepanone (IV), aldehyde (V), and diacetates (VII).