O. G. Bondarev

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.

Complexing and catalytic properties of easily available chiral iminophosphite based on biphenyl-2,2"-diol

A chiral iminophosphite ligand based on biphenyl-2,2-diol and its chelates with rhodium(i) and palladium(ii) were synthesized for the first time. Successful use of these compounds in asymmetric allylic substitution was demonstrated. The enantioselectivity of palladium-catalyzed alkylation of methyl pent-3-en-2-yl carbonate with dimethyl malonate reached 70%, that in the alkylation of 1,3-diphenylallyl acetate with dimethyl malonate was 88%. In the rhodium-catalyzed sulfonylation of 1,3-diphenylallyl acetate with sodium p-toluenesulfinite, the enantioselectivity was 56%.

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.

Pd-catalyzed asymmetric allylation of an o-carborane derivative

The asymmetric synthesis of methyl 2-phenyl-2-(2-phenyl-ortho-carboran-1-yl)pent-4-enoate was carried out by palladium-catalyzed allylation in the presence of amino phosphites of the type (RO)2P—O—CH2—CHR—NR″2 as chiral ligands.

Synthesis of new acyclic aminophosphites and their chelate complexes with rhodium(i) and palladium(ii)

New acyclic aminophosphites (RO)2POCH2CH2NMe2 (PN) (R=Et, Pri, or adamantyl) characterized by various steric requirements of the phosphorus center were synthesized. The reactions of the aminophosphites with Pd(COD)Cl2 (COD is 1,5-cyclooctadiene) and [Rh(CO)2Cl]2 afforded the stable chelate mononuclear complexes PdCl2(PN) and RhClCO(PN), respectively. The structures of the resulting compounds were established by1H,13C, and31P NMR and IR spectroscopy, X-ray diffraction analysis, laser and plasma desorption mass spectrometry, X-ray photoelectron spectroscopy, and sedimentation analysis.

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.