Vasily N. Tsarev

New oxazoline-containing phosphoramidite ligand for palladium-catalyzed asymmetric allylic sulfonylation

New chiral oxazoline-containing phosphoramidite was synthesized and its complex formation with rhodium(i) and palladium(ii) was examined. The new ligand is a highly efficient chiral inductor (ee up to 92%) in palladium-catalyzed asymmetric sulfonylation of 1,3-diphenylallyl acetate with sodium p-toluenesulfinate.

Palladium-catalyzed asymmetric allylation and complex formation involving P,N-bidentate derivatives of (S)-2-(anilinomethyl)pyrrolidine

P,N-Bidentate (S)-2-(anilinomethyl)pyrrolidine derivatives and their complexes with rhodium(i) and palladium(ii) were synthesized. It was demonstrated that these compounds can be used in the Pd-catalyzed asymmetric allylation for the synthesis of chiral methyl 2-phenyl-2-(2-phenyl-o-carboranyl-1)pent-4-enoate.

Platinum and rhodium complexes with isoleucinol-based bi- and tricyclic hydrophosphoranes

The complex formation of bi- and tricyclic hydrophosphorane derivatives of isoleucinol with [Pt(COD)Cl2], [Rh(CO)2Cl]2, and [Rh(THF)2(COD)]+BF4– (COD is cycloocta-1,5-diene) was investigated. In all cases, bicyclic hydrospirophosphorane selectively forms the metal chelates [M(η2-P∩N)(X)Cl] (M = Pt, X = Cl; M = Rh, X = CO) and [Rh(η2-P∩N)(COD)]+BF4–. («∩» denotes the residue of the hydrospirophosphorane ligand, which does not contain the P and N atoms). In addition, tricyclic hydrophosphorane (L) generates the phosphoranide complexes [Pt(η1-L)(COD)Cl]+Y– (Y = Cl or BF4). The structures of the new compounds were established by IR spectroscopy, 31P, 13C, 1H, 2H, 11B, 19F, and 195Pt NMR spectroscopy, and plasma-desorption and electrospray ionization mass spectrometry. The possible mechanism of coordination of hydrophosphoranes is discussed.

A first P,N-bidentate phosphite with a chiral ketimine fragment. Catalytic properties of its RhI and PdII complexes in comparison with those of phosphine analogs

A chiral P,N-bidentate aryl phosphite ligand containing peripheral (R)-(+)-camphor-derived ketimine and its rhodium(I) and palladium(II) chelate complexes were synthesized for the first time. These compounds were found to be suitable for asymmetric allylic substitution. The Pd-catalyzed sulfonylation of 1,3-diphenylallyl acetate with sodium p-toluenesulfinate gave the product in 73% ee; in the alkylation of the same substrate with dimethyl malonate, the ee was 94%. These ee values are higher than the enantioselectivity achieved with the known phosphine analogs.

First quinine-based aryl phosphite: synthesis and application in the Pd-catalyzed enantioselective rearrangement of allylic thiocarbamate

New quinine-based polyfunctional aryl phosphite was synthesized. The phosphorus center in the new compound is characterized by a large cone angle (θ = 190°). The new compound can be used in the Pd-catalyzed enantioselective rearrangement of cyclic O-allylic thiocarbamate into S-allylic thiocarbamate in an optical yield of up to 47% with a quantitative conversion.