Véronique Michelet

Synthesis of Functionalized 1H-Isochromene Derivatives via a Au-Catalyzed Domino Cycloisomerization/Reduction Approach.

A Au-catalyzed versatile and efficient access to 1H-isochromenes is reported. The efficiency of the [AuCl2(Pic)] complex (1-5 mol %) was demonstrated and allowed a domino cycloisomerization/reduction reaction process starting from a wide range of functionalized ortho-alkynylbenzaldehydes and one example of ortho-alkynylpyridinylaldehyde. The smooth reaction conditions were amenable to aryl- and alkyl-substituted alkynyl derivatives, as well as functionalized halogen and ether moieties, leading to a chemo- and regioselective 6-endo-cyclization with good to excellent yields.

Copper(I)-amine metallo-organocatalyzed synthesis of carbo- and heterocyclic systems.

The efficient and atom economical synthesis of 5-membered cyclic structures has been achieved through the combination of amino catalysis and metal catalysis. The discovery of a novel metallo-organocatalytic system merging the use of a catalytic copper(I) complex and a catalytic amount of cyclohexylamine allowed the room temperature preparation of a broad range of skeletons such as cyclopentanes, indanes, pyrrolidines and tetrahydrofuran, important structural cores of many biologically relevant molecules. Mechanistic studies were presented.

Iridium(III)‐Catalyzed Approach for the Synthesis of Fused Arenes: Access to Isoindolines, Indanes, and Dihydroisobenzofurans

A facile and efficient method for the synthesis of isoindoline, indane, and dihydroisobenzofuran derivatives has been developed through the application of a halogen‐bridged iridium(III) complex to the [2+2+2] cycloaddition of α,ω‐diynes with alkynes. The cycloaddition tolerates a broad range of substitution groups, such as alcohol, alkyl, ether, and halogen, and the chemistry can be extended to prepare the corresponding borylated fused arenes. The reaction shows that hindered starting materials are also good partners, which provide the desired fused arenes in good yields.

Gold-Catalyzed Domino Reactions

Gold-catalyzed reactions have appeared to be highly attractive tools for chemists to promote novel transformations to prepare elaborated structures from simple starting materials. This chapter presents selected and original examples of domino processes in the presence of gold catalysts, highlighting reports implying hydration, hydroxylation, and hydroamination as key starting point for cascade transformations. Domino processes implying 1,n-enynes, asymmetric domino transformations, and applications of all the presented processes in total synthesis are presented.

A NEW SYNTHETIC APPROACH TOWARD (+)-AMBRUTICIN ANALOGS : PREPARATION OF A C10-C11 CIS-ISOMER FRAGMENT

A new methodology has been applied to synthesize an isomer of the west part of (+)-ambruticin based on an efficient asymmetric de novo access to the A unit and sequential stereospecific reactions catalyzed by Pd0 for the construction of the B unit.

Silver- versus gold-catalyzed sequential oxidative cyclization of unprotected 2-alkynylanilines with oxone

Unprecedented domino oxidative cyclization reactions of unprotected 2-alkynylanilines to give functionalized 4H-benzo[d][1,3]oxazin-4-one or benzisoxazole derivatives in moderate to good yields are achieved by silver vs. gold selective catalysis. The search for the optimal reaction conditions revealed the divergent catalytic activity of NaAuCl4·H2O and AgNO3.

Solvent-free ruthenium trichloride-mediated [2 + 2 + 2] cycloaddition of α,ω-diynes and cyanamides: a convenient access to 2-aminopyridines

A convenient access to functionalized 2-aminopyridines via a solventless Ru-catalyzed [2 + 2 + 2] cycloaddition reaction of α,ω-diynes and cyanamides is described. This transformation efficiently proceeds in the presence of a stable, easy to handle, and cost-effective RuCl3·nH2O complex, leading to various 2-aminopyridines in good to excellent yields according to an eco-friendly, straightforward approach.

Synthesis of Fluorescent Azafluorenones and Derivatives via a Ruthenium-Catalyzed [2 + 2 + 2] Cycloaddition

An original and mild synthetic route for the preparation of novel azafluorenones and derivatives via a ruthenium-mediated [2 + 2 + 2] cycloaddition of α,ω-diynes and cyanamides has been developed. This atom-economical catalytic process demonstrated remarkable regioselectivities to access fluorescent azafluorenone derivatives. The photophysical properties of azafluorenone derivatives have been evaluated, and photoluminescence phenomena at solid and liquid states have been highlighted.

Gold-Catalyzed Cascade Reaction of β-(2-Aminophenyl)-α,β-ynones with Ynamides: A Sequential Route to Polysubstituted 2-Aminoquinolines

A novel, efficient, and mild synthetic route for the preparation of 2-aminoquinolines via a gold-catalyzed cascade reaction of β-(2-aminophenyl)-α,β-ynones with ynamides has been developed. This process tolerates a wide range of functionalities such as halogen, alkyl, aryl, and heteroaryl groups, leading to original heterocycles in fair to very good yields.

Synthesis of 2-aminopyridines via ruthenium-catalyzed [2+2+2] cycloaddition of 1,6- and 1,7-diynes with cyanamides: scope and limitations

A practical and mild process to access 2-aminopyridine derivatives using ruthenium-catalyzed [2+2+2] cycloaddition of various 1,6- and 1,7-diynes with cyanamides is described. This straightforward atom-economical catalytic cycloaddition is scalable and showed excellent regioselectivities to approach a wide range of 2-aminopyridines of high synthetic utility. Postfunctionalization reactions of halo-containing adducts, via Pd- and Cu-catalyzed cross-couplings as well as cyanation and amination reactions, delivered substituted 2-aminopyridine derivatives in good to excellent yields.