Marina G. Maksimova

First chiral phosphite with a quaternary ammonium fragment : synthesis and use in Rh-catalyzed asymmetric hydrogenation

The first representative of chiral P-monodentate phosphite ligands containing quaternary ammonium substituents and its rhodium complex [Rh(COD)(L)2]BF4 (COD is 1,5-cycloctadiene) were obtained. The use of this ligand in Rh-catalyzed asymmetric hydrogenation of prochiral methyl esters of unsaturated acids allowed one to achieve optical yields up to 99%.

Chiral phosphite-type ligands based on ((4 R ,5 R )-2,2-dimethyl-1,3-dioxolane-4,5-diyl)bis(diphenylmethanol) (( R , R )-TADDOL) with peripheral arylamino groups

New phosphite and amidophosphite inductors of chirality were obtained based on ((4R,5R)-2,2-dimethyl-1,3-dioxolane-4,5-diyl)bis(diphenylmethanol) ((R,R)-TADDOL) containing arylamino groups in the exocyclic substituents. Their use in the palladium-catalyzed enantioselective alkylation of (E)-1,3-diphenylallyl acetate with dimethyl malonate gave the ee value up to 98%.

Iridium-catalyzed regiospecific allylation of dimethyl malonate in ionic liquids

Allylation of dimethyl malonate with 1-(4-chlorophenyl)prop-2-enyl methyl carbonate in the presence of [Pd(All)Cl]2, [Rh(COD)Cl]2, [Ir(COD)Cl]2 (COD is cycloocta-1,5-diene), and a chiral ferrocenyl-containing phosphite ligand based on (R)-BINOL (BINOL is 2,2′-dihydroxy-1,1′-binaphthyl) in CH2Cl2 gave a mixture of linear and branched cross-coupling products, the latter having a moderate optical purity (below 51%). The rhodium-and iridium-catalyzed reactions were very highly regioselective (regiospecific in the case of Ir), giving a branched product. In ionic liquids ([bmim][BF4] and [bdmim][BF4]) (bmim is 1-butyl-3-methylimidazolium and bdmim is 1-butyl-2,3-dimethylimidazolium), the Ir-catalyzed reaction regiospecifically afforded a branched product as a racemate. The same result was obtained with [Ir(COD)Cl]2 as a catalyst; this reaction easily occurred in ionic liquids even without a base.

Phosphorylated (S)-tert-leucinol isophthalic diamide as a ligand for Pd-catalyzed asymmetric allylic substitution

O-Phosphorylation of N,N’-(isophthaloyl)di-(S)-tert-leucinol with (5S)-2-chloro-3-phenyl-1,3-diaza-2-phosphabicyclo[3.3.0]octane afforded bidentate phosphite-type ligand. This ligand provided 93% ee in Pd-catalyzed enantioselective allylation of (E)-1,3-diphenylallyl acetate, and 55% ee in alkylation of cinnamyl acetate with ethyl 2-oxocyclohexane-1-carb-oxylate.

Diastereomeric bisamidophosphites based on oxalamide 1,3-diol in asymmetric metal complex catalysis

Diastereomeric P*,P*-bisdiamidophosphite ligands of the 1,3,2-diazaphospholidine series bearing an oxalamide moiety have been synthesized. A possibility of their application in palladium- and rhodium-catalyzed asymmetric transformations was demonstrated. In Pd-catalyzed sulfonylation of (E)-1,3-diphenylallyl acetate with sodium p-toluenesulfinate enantioselectivity of up to 57% ee, in alkylation with dimethyl malonate of up to 77% ee, in amination with pyrrolidine of up to 78% ee, and in alkylation of cinnamyl acetate with ethyl 2-oxocyclohexane-1-carboxylate of up to 52% ee, in Rh-catalyzed hydrogenation of (Z-methyl 2-acetamido-3-phenylacrylate of up to 88% ee was achieved. An effi ciency of diastereomeric chirality inducers was compared.

An alliance between chiral phosphite-type compounds and porphyrins in asymmetric palladium catalysis

GRAPHICAL ABSTRACT ABSTRACT Some novel results obtained at the confluence of organophosphorus and porphyrin chemistry are briefly overviewed. The focus is put on the P*-chiral porphyrin-appended diamidophosphite ligands as well as achiral metalloporphyrins used in Pd-catalyzed asymmetric allylation.