K. N. Gavrilov

Reactions of chiral phosphoramidites with complexes Pd(COD)Cl2 and Pt(COD)Cl2

Reactions of phosphoramidites based on (−)-ephedrine and [(1S)-endo]-(−)-borneol with the complexes M(COD)Cl2 (M is Pd or Pt, and COD is cycloocta-1,5-diene) were studied. The formation ofcis andtrans complexes of the general formulas MCl2L2 and M2Cl2(μ-Cl)2L2 was observed. The structures of the resulting compounds were established by31P,13C, and195Pt NMR and IR spectroscopy and by plasma desorption mass spectrometry.

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.

Novel planar chiral phosphite: Preparation and use in the synthesis of Pd(II) complexes and in Pd-catalyzed allylic alkylation

The planar chiral diaryl phosphorimidite ligand containing additional C-stereocenters and neutral and cationic palladium(II) chelates with this ligand, cis-[Pd(η2-P,N)Cl2] and [Pd(Allyl)(η2-P,N)]BF4, were synthesized for the first time. The possibility of using these compounds in asymmetric allylic alkylation of 1,3-diphenylallyl acetate with dimethyl malonate in an optical yield of up to 73% was demonstrated.

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.

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.

Chiral P,N-bidentate N-pyrrolylphophines as ligands with remarkable electronic properties

Previously unknown chiral P,N-bidentate N-pyrrolylphosphines and their chelate complexes [Rh(η2-P,N)(CO)Cl] and [Pd(Allyl)(η2-P,N)]BF4 were synthesized by phosphorylation of (E,1R,2R,3R,5S)-2-[(2,6,6-trimethylbicyclo[3.1.1]heptyl-3-)iminomethyl]-1H-pyrrole. The composition and structures of the novel compounds were determined by the 1H, 13C, and 31P NMR, IR, mass spectrometry (electrospray), and elemental analysis methods. N-pyrrolylphosphines were found to have unusual electronic properties, being simultaneously more strong π-acids and σ-bases as compared to phosphites.

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.

Asymmetric Pd-catalyzed allylic amination of 1,3-diphenylallyl acetate with dipropylamine in ionic and molecular solvents

Asymmetric catalytic allylic amination of 1,3-diphenylallyl acetate with dipropylamine in an ionic liquid, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, and in THF and CH2Cl2 in the presence of palladium complexes of P-monodentate phosphite and phosphoramidite derivatives of S-1,1′-bis-2-naphthol was carried out. This gave a product with ee of up to 65%. The level of asymmetric induction is retained after three catalyst cycles.

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.