Jean-Louis Canet

A simple and efficient enantioselective synthesis of piperidine alkaloids dihydropinidine and isosolenopsins A, B and C

Abstract A diastereospecific intramolecular Mannich-type reaction, involving enantiopure amine 4 and achiral aldehydes, is employed as the key step of an efficient total enantioselective synthesis of five piperidine alkaloids.

A practical asymmetric synthesis of 2,6-cis-disubstituted piperidines

Abstract A highly diastereoselective intramolecular Mannich reaction involving enantiopure α-methylamine 7 and achiral aldehydes is employed to prepare enantiomerically pure 2,6- cis -disubstituted piperidines. This methodology provides an efficient and selective route to 2,6- cis -disubstituted piperidines, 2,6- cis -disubstituted 4-piperidones and 2,6- cis -disubstituted 4-piperidinols.

A new route to 2-spiropiperidines

An intramolecular Mannich reaction, involving cyclanones together with a ketoprotected aminobutanone in the presence of a Lewis acid, is employed to prepare rapidly 2,2′-spiropiperidine skeletons. This approach is validated through a concise and efficient synthesis of spiro [piperidine-2,2′-adamantane] 4, an antiviral agent.

Diastereoselective elaboration of 2,3,4-substituted piperidines using diene iron tricarbonyl complexes. Total synthesis of (±)-dienomycin C and (±)-4-epi-dienomycin C

The diastereoselective formation of 2,3,4-substituted piperidines is achieved by condensation of the iron dienal complex 2 and the primary amine 3 via an intramolecular Mannich-type cyclisation. This method is illustrated by the first total synthesis of (±)-dienomycin C 1 and its C-4 epimer 9.

A rapid stereoselective access to highly substituted piperidines

Abstract An intramolecular Mannich reaction, involving various achiral aldehydes together with an α-chiral amine is employed as the key step for a stereocontrolled synthesis of highly substituted piperidine systems. Accordingly, 12 new piperidines bearing four asymmetric centers were prepared in six steps from commercial ketones.

Monodisperse silica nanoparticles doped with dipicolinic acid-based luminescent lanthanide(III) complexes for bio-labelling

The facile synthesis of functionalized luminescent nanoparticles from LnL3 lanthanide complexes is described. The luminescence properties of the lanthanide chelates and of the corresponding nanohybrids are reported and compared. For a further application in bioimaging, the cytotoxicity of the nano-objects was investigated.

Sol–gel emulsion synthesis of biphotonic core–shell nanoparticles based on lanthanide doped organic–inorganic hybrid materials

Eu3+ and Tb3+ complexes based on an organo-alkoxysilane derived from 4-azido dipicolinic acid by “click chemistry” were coated onto silica nanoparticles previously prepared by the water in oil emulsion method. Structural and optical properties of the resulting luminescent core–shell monodisperse (30 nm) nanohybrids were fully characterized by infrared and Raman spectroscopies as well as by electron microscopy. Fluorescence spectroscopy evidenced that an efficient ligand-to-Ln3+ energy transfer—both in the mono- and biphotonic modes—occurs. Furthermore, surface modification by amino groups was realized, paving the way for nanotags of biological interest.

Stereoselective Synthesis of Substituted Piperidines – Total Synthesis and Absolute Configurations of (+)- and (–)-Dienomycin C

The first total asymmetric synthesis and the attribution of the absolute configurations of (+)-dienomycin C (1), an alkaloid isolated from a Streptomyces strain, are reported. This compound was prepared in six steps from the enantiopure tricarbonyl(dienal)iron complex (+)-4 which is easily obtained by separating preformed diastereomers, starting from phenylpentadienoic acid and (S)-methyl mandelate.

Clicked Europium Dipicolinate Complexes for Protein X-Ray Structure Determination.

New trisdipicolinic acid-lanthanide complexes are reported as phasing agents for X-ray crystallography of proteins. It is demonstrated that CuAAC modifications allow protein co-crystallization with low concentration of lanthanide complexes leading to an accurate structure determination.

A simple synthesis of (+)- and (−)-alkaloid 241D and C-4 epimers

An enantioselective preparation of both enantiomers of alkaloid 241D 1 and its C-4 epimer is reported. This simple and concise synthesis, seven steps from pent-3-en-2-one, involves a highly diastereoselective Mannich-type cyclisation as the key step.