Nouveau Composes Chiraux Dérives d’une Diamine ou d’un Aminoalcool, Monosulfonylés et carbonylés Porteurs d’un Groupe Pyrrolidinyle. Leur Préparation et Leurs Applications en Catalyse Asymétrique

Chiral esters and amides (I) of pyrrolidine-2-carboxylic acid are new. - Chiral esters and amides of pyrrolidine-2-carboxylic acid, having formula (I), are new. - A = groups F1 or F2; - R' and R'' = 1-20C hydrocarbyl, i.e. acyclic, linear or branched, saturated or unsaturated aliphatic, carbo- or hetero-cyclic, mono- or poly-cyclic, saturated, unsaturated or aromatic, or a chain of such groups, or R' and R'' are linked to form a 4-20 atom carbo- or hetero-cyclic group, saturated, unsaturated or aromatic, mono- or poly-cyclic; - Ar1 and Ar2 = two aromatic, carbo- or hetero-cyclic, rings optionally substituted, fused and/or containing one or more heteroatoms; - x and y = bonds between A and heteroatoms; - Rf = 1-20C hydrocarbyl, optionally containing at least one halo, preferably fluoro; - Rz = one or more substituents on pyrrolidinyl; - G = a chiral group; - W = O or RyN; - Ry = 1-20C hydrocarbyl as for R', or a chain of such groups; - n = number of ring substituents; - m = 0-3, preferably 0 or 1; - the wavy line = chiral bond; - the broken line = chiral or non-chiral bond. - An INDEPENDENT CLAIM is also included for a method for preparing (I) by reacting an N-protected pyrrolidine-2-carboxylic acid (or alkyl ester) with the appropriate alcohol or amine

Utilisation d'un acide carboxylique aromatique dans une réaction de catalyse asymétrique faisant intervenir des composés chiraux d'une diamine ou d'un aminoalcool,monosulfonylés et carbonylés porteurs d'un groupe pyrrolidinyle.

La présente invention a pour objet l'utilisation d'un acide carboxylique aromatique dans une réaction de catalyse asymétrique faisant intervenir à titre de catalyseurs, des composés chiraux dérivés d'une diamine ou d'un aminoalcool, monosulfonylés et carbonylés, porteurs d'un groupe pyrrolidinyle. L'invention vise plus particulièrement les réactions d'aldolisation ou de cétolisation asymétrique

Synthesis of 3-substituted tetrahydrofuran and 4-substituted tetrahydropyran derivatives by cyclization of dicarboxylic acids with InBr3/TMDS

International audienceAn efficient reduction followed by cyclization of diacid compounds with the InBr3/TMDS system is reported. This system allows the formation of five- and six-membered ring ethers substituted in the 3- or 4-positio

Reduction of phosphine oxides to phosphine with the InBr3/TMDS system

International audienceAn efficient method for the reduction of phosphine oxide derivatives into their corresponding phosphines is described. The system InBr3/TMDS allows the reduction of different secondary and tertiary phosphine oxides as well as aliphatic and aromatic phosphine oxides

A new solvent-free reaction for the preparation of alkoxysilane from cyclic ethers, alcohols or carbonyl compounds.

International audienceThe 1,1,3,3-tetramethyldisiloxane/Pd/C system is reported here as a new method to accomplish the ring-opening of ethers and epoxides to give protected alcohols. The approach can also be used for the protection of primary or secondary alcohols and for the reduction of aldehydes and ketones to obtain alkoxysilanes

A mild titanium-based system for the reduction of amides to aldehydes

International audienceA mild method for the reduction of amides to aldehydes using 1,1,3,3-tetramethyldisiloxane/titanium(IV) isopropoxide reducing system is described. The reaction occurs under mild conditions and allows the reduction of aromatic as well as aliphatic, tertiary amides to the corresponding aldehydes, in good yields. This methodology was extended to the reduction of aromatic secondary and primary amides to the corresponding aldehydes

An improved and safer synthesis of (R)- and (S)-4,4'-diaminomethyl-BINAP.

International audience(R)- and (S)-4,4′-diaminomethyl-BINAP were prepared in three steps from enantiomerically pure BINAPO in a global yield of 52 %. A regioselective bromination of BINAPO with NBS in HMimPF6 gave the desired 4,4′-dibromo-BINAPO in quantitative yield, and the recyclability of the ionic liquid was demonstrated. Copper cyanide cyanation of 4,4′-dibromo-BINAPO gave the 4,4′-dicyano-BINAPO in 70 % yield. Both enantiomers were characterized by NMR spectroscopy and HPLC analysis, and the structures were confirmed by X-ray crystallography. The cyano and phosphane oxide groups of the resulting 4,4′-dicyano-BINAPO were reduced in one step to the corresponding 4,4′-diaminomethyl-BINAP by using tetramethyldisiloxane/Ti(OiPr)4 in 75 % yield

Reduction of aromatic and aliphatic esters- using the reducing systems MoO2(acac)2 or V(O)(OiPr)3 in combination with 1,1,3,3-Tetramethyldisiloxane

International audienceAn efficient reduction of aromatic and aliphatic esters with 1,1,3,3-tetramethyldisiloxane in combination with [MoO2(acac)2] or [V(O)(OiPr)3] is reported. In the former system, the presence of triphenylphosphane oxide allows high conversion and good isolated yield to be reached. For the latter system, no ligand is necessary to obtain the corresponding alcohols with similar results

Iron-catalyzed selective reduction of nitro compounds to amines.

International audienceAn efficient reduction of the nitro group with a catalytic amount of Fe(acac)3 and TMDS in THF at 60 °C affording the corresponding amine is described