Bertrand Carboni

Diels-Alder reactions of 1,3-dienylboronates as a new route to functionalized carbocycles.

Abstract Hydroboration of enynes with various hydroborating agents followed by refunctionalization at boron furnished 1,3-dienylboronates which undergo clean Diels-Alder addition to typical dienophiles. The resulting adducts contain an allylboronate functionality. Accordingly they add to aldehydes in a highly stereoselective fashion establishing the relative configuration at up to four stereogenic centers.

Boronic ester as a linker system for solid phase synthesis

Abstract A method for attaching boronic acids to a macroporous polymer-supported 1,3-diol was developed. Chemical modifications of some polymer-bound arylboronic acids were realised using various reaction conditions. Trans-esterification gave new boronates in high purity while oxidative cleavage directly led to phenols.

Chiral boronates—versatile reagents in asymmetric synthesis

Abstract The new, axially chiral borates 2, 9, and 11 and boronates 3–6 and 12 are synthesized in good yields. They are representatives of three different structural types. The bicyclic borates 2 and 9 are homochiral propeller compounds; their exclusive formation is used to increase the enantiomerical purity of 1. Especially the borates are efficient Lewis acidic catalysts for stereoselective Diels–Alder reactions. The new seven-membered boron compounds 4, 5, 6, and 12 are interesting reagents for different asymmetric synthetic steps. Activated vinylboronates 31 can serve as efficient cyclophiles in [3+2] cycloaddition reactions with methylenecyclopropane 27 giving borylated methylenecyclopentanes 32.

Etude de la chimioselectivite de la reaction des dichloroboranes avec les azides fonctionnels : une synthese efficace d'amines secondaires fonctionnalisees.

Abstract The reaction of cyclohexyldichloroborane, used as a model, with a wide variety of functionalized azides has been studied. It has been shown to be an efficient synthesis of secondary amines in terms of chemioselectivity, yields and wide applicability.

Ruthenium-Catalyzed Synthesis of Allylic Alcohols : Boronic Acid as a Hydroxide Source

Secondary allylic alcohols were synthesized from linear allylic halides or carbonates using a catalytic amount of a ruthenium complex in the presence of boronic acid. The effects of solvent, base, ruthenium precursor, and boronic acid were fully explored, and the scope of the reaction was extended to various substrates. We also describe a preliminary investigation towards an enantioselective process.

Radical reactions in organoboron chemistry II — Inter- and intramolecular addition of carbon centered radicals to alkenylboranes

Abstract The intermolecular addition of carbon centered radicals to alkenylboranes has been studied. The influence of the olefin and boron substituents on the reactivity and the regioselectivity was determined. Competitive experiments were carried out to estimate the relative reactivity of a series of vinylboranes and other electron deficient alkenes. Intramolecular versions of these additions were also described as well as some further transformations of selected adducts.

Synthesis of 1,2-aminoazides. Conversion to unsymmetrical vicinal diamines by catalytic hydrogenation or reductive alkylation with dichloroboranes.

Abstract 1,2-aminoazides are easily prepared from 1,2-amino alcohols. Catalytic hydrogenation in the presence of palladium on charcoal or reductive alkylation with dichloroboranes afford with good yields unsymmetrically substituted vicinal diamines.

A new access to 2-hydroxymorpholines through a three-component Petasis coupling reaction

Abstract 2-Hydroxymorpholines bearing a variety of substituents were prepared via the one-pot three-component reaction of a 1,2-aminoalcohol, an organoboronic acid and a glyoxal derivative.

Solid phase organic synthesis of polyamine derivatives and initial biological evaluation of their antitumoral activity

A series of N1-monosubstituted putrescine and spermine derivatives was synthesised using a solid phase methodology. We evaluated their cytotoxicity, calmodulin antagonism and polyamine uptake inhibition, pharmacological properties shared by some antitumoral agents.

Synthesis of the marine sponge alkaloid oroidin and its analogues via Suzuki cross-coupling reactions

A new synthesis of the natural product oroidin was described using a Suzuki coupling reaction as key step. This method was extended to the synthesis of various analogues of oroidin and hymenidin.