I. M. Novikov

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.

Pd-Catalyzed asymmetric transformations involving P*-mono- and P*,N-bidentate diamidophosphites derived from (2S,3S)-N2,3-dimethyl-N1-phenylpentane-1,2-diamine

The synthesis of new P*-mono- and P*,N-bidentate diamidophosphites, containing 1,3,2-diazaphospholidine rings formed starting from (2S,3S)-N2,3-dimethyl-N1-phenylpentane-1,2-diamine, is described. Comparison of their efficiency in the Pd-catalyzed enantioselective allylation with (E)-1,3-diphenylallyl acetate showed that up to 97% ee was reached in the reaction involving dimethyl malonate as a C-nucleophile. The Pd-catalyzed desymmetrization of N,N′-ditosyl-meso-cyclopent-4-ene-1,3-diol biscarbamate gave up to 61% ee.

First ligand of phosphite nature based on 5,10,15,20-tetrakis(4-hydroxyphenyl)porphin

Supramolecular asymmetric catalytic systems are formed involving chiral phosphites and amidophosphites underlain by metalloporphyrins [9–15], yet only one chiral phosphite has been prepared with a porphyrin fragment without a metal ion [9]. No published information exists on diamidophosphite porphyrin derivatives, in particular, with asymmetric phosphorus atoms, and also on compounds containing in their composition more than one phosphorus site linked to the porphyrin scaffold.

Palladium and rhodium-catalyzed enantioselective reactions mediated by pseudodipeptide-based phosphite-type ligand

P*-Chiral diamidophosphite ligand of a 1,3,2-diazaphopholidine series bearing the exocyclic pseudodipeptide fragment was synthesized. The possibility of its application in the palladium- and rhodium-catalyzed asymmetric transformations was demonstrated. This ligand provided up to 84% ee in the Pd-catalyzed alkylation of (E)-1,3-diphenylallyl acetate with dimethyl malonate, up to 56% ee in amination of this substrate with pyrrolidine, and up to 68% ee in alkylation of cinnamyl acetate with ethyl 2-oxocyclohexane-1-carboxylate. In the Rh-catalyzed hydrogenation of (Z)-methyl 2-acetamido-3-phenylacrylate mediated by this ligand, up to 53% ee was achieved.