Ilya A. Zamilatskov

Palladium-catalyzed enantioselective allylation in the presence of phosphoramidites derived from (Sa)-3-SiMe3-BINOL, (R,S)-semi-TADDOL, and (R,R)-TADDOL

Novel P*- and P-monodentate phosphoramidites of a 1,3,2-dioxaphosphepine series were derived from (Sa)-3-trimethylsilyl-BINOL, (R,S)-semi-TADDOL, and (R,R)-TADDOL. Catalytic performance of the synthesized compounds were examined in the Pd-catalyzed asymmetric allylic substitution of (E)-1,3-diphenylallyl acetate: the reaction with dimethyl malonate gave up to 92% ee. The effects of additives of 5,10,15,20-tetraphenylporphyrin and its metal complexes on conversion and enantioselectivity were studied.

Chiral amido- and diamidophosphites with a peripheral pyridine ring in Pd-catalyzed asymmetric allylation

New chiral amidophosphite and diamidophosphite ligands with exocyclic pyridyl-containing substituents were obtained. Their efficiency in the Pd-catalyzed enantioselective allylic substitution was compared: in the sulfonylation of (E)-1,3-diphenylallyl acetate with sodium p-toluenesulfinate, the ee can reach 77%; its alkylation with dimethyl malonate and amination with pyrrolidine gave up to 80% and 74% ee, respectively. The asymmetric alkylation of cinnamyl acetate with ethyl 2-oxocyclohexanecarboxylate can provide to 68% ee. The complexation of zinc(ii) 5,10,15,20-tetraphenylporphyrinate with diamidophosphite ligand and its influence on conversion and enantioselectivity of the process were studied.

First P,P*-bidentate phosphine-phosphite-type ligand with a P*-stereocenter in the phosphite moiety: synthesis and application in the Pd-catalyzed asymmetric allylic alkylation

A new P,P*-bidentate phosphine-diamidophosphite bearing an asymmetric phosphorus atom in the 1,3,2-diazaphospholidine ring was obtained. A possibility of its application in the palladium-catalyzed enantioselective allylic substitution was demonstrated. A 70% ee was reached in the alkylation of (E)-1,3-diphenylallyl acetate with dimethyl malonate.

Cobalt(II), nickel(II), and copper(II) complexes of 14-membered hexaazamacrocycles: synthesis and characterization

Cobalt(II), nickel(II), and copper(II) complexes containing 5,12-di(4-bromophenyl)-7,14-dimethyl-1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-dione (H2L1) and 5,12-diphenyl-7,14-dimethyl-1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-dione (H2L2) have been synthesized. All complexes were characterized by elemental analysis, MALDI TOF-MS spectrometry, and electronic absorption spectroscopy. The crystal structures of two compounds, [Cu2(H2L1)Cl4]n and [NiL2], were determined by X-ray powder diffraction. In the polymeric [Cu2(H2L1)Cl4]n, the Cu2Cl4 units and H2L1 molecules are situated on inversion centers. Each Cu(II) has a distorted trigonal-bipyramidal coordination environment formed by N and O from H2L1 [Cu–N 2.340(14) Å, Cu–O 1.952(11) Å], two bridging chlorides [Cu–Cl 2.332(5), 2.279(5) Å] and one terminal chloride [Cu–Cl 2.320(6) Å]. In the [NiL2] complex, the Ni(II) situated on inversion center has a distorted square-planar coordination environment formed by four nitrogens from L2 [Ni–N 1.860(11), 1.900(11) Å]. Graphical Abstract

Diamidophosphite based on (1R,2R)-1,2-bis(3-hydroxybenzamido)cyclohexane in Pd-catalyzed enantioselective allylation

Diamidophosphite ligand bearing (1R,2R)-1,2-bis(3-hydroxybenzamido)cyclohexane fragment and stereogenic phosphorus atoms in the 1,3,2-diazaphopholidine cycles was synthesized. Catalytic performance of this ligand was evaluated in asymmetric allylic substitution. In the reactions involving (E)-1,3-diphenyl allyl acetate as a substrate, up to 94% ee in alkylation with dimethyl malonate and up to 68% ee in amination with pyrrolidine was achieved in the presence of this ligand.

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.

Structural explanation of the spectral features of the nonsymmetrical complex {2,3,7,8,12,13,17,18-octaethyl-5-[(methylimino) methyl] porphyrinato-kappa(4) N-21, N-22, N-23, N-24} palladium(II)

The features of porphyrins defining their functionality are related to their conformational flexibility. The degree of nonplanarity of metalloporphyrins depends directly on the number of substituents, their size and their location. The introduction of substituents in the meso positions of β-substituted porphyrins increases the steric interaction and leads to distortions of the porphyrin core. Increasing the distortion of the porphyrin core would augment the bathochromic (red) shift of the electronic absorption spectra. A new nonsymmetrical 2,3,7,8,12,13,17,18-octaethyl-5-[(methylimino)methyl]porphyrin complex of palladium(II), [Pd(C38H47N5)], was synthesized and characterized by NMR, mass spectrometry and X-ray analysis. The features of the electronic absorption spectrum of the synthesized complex are explained by the planarity of the porphyrin core and the π-system of the imino group orthogonal to it.