E. D. Lubuzh

Bio: E. D. Lubuzh is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Enantioselective synthesis & Aminolysis. The author has an hindex of 2, co-authored 29 publications receiving 17 citations.

Asymmetric synthesis of amino acids via the catalytic reduction of substituted acylaminoacrylic acid azlactones: 26. Aminolysis of 2-methyl-4-benzyloxazolin-5-one upon reaction with S-phenylalanine derivatives

Abstract: The kinetics of aminolysis and racemization of 2-methyl-4-benzyloxazolin-5-one upon reaction with S-phenylalanine methyl ester have been studied in dimethoxyethane solvent. The rates of aminolysis and racemization are comparable. Addition of an achiral component, namely Et3N, to the reaction mixture, however, dramatically increases the rate of racemization. The presence of Et3N also increases the ratio of rate constants for the formation of RS- and SS-diastereomers, which determines the reaction stereoselectivity.

Reactions of lithium-biphenyl adducts with carbonyl compounds

Abstract: 1. The reactions of lithium-biphenyl adducts in tetrahydrofuran solution with acetaldehyde, benzaldehyde, acetone, cyclohexanone, and ethyl octanoate were carried out. 2. The reaction of lithium-biphenyl adducts with carbonyl compounds takes two courses: condensation of the carbonyl compounds, and organolithium synthesis with formation of alcohols and diols.

Addition of arylfluorosilanes containing silicon-attached hydrogen

Abstract: 1. In additions to unsaturated compounds in presence of a H2PtCl6 catalyst, hydride arylfluorosilanes are considerably more reactive than their chloro analogs. 2. The arylfluorosilyl groups of difluorophenylsilane and difluoro-1-naphthylsilane add at both of the carbon atoms of the vinyl group of styrene (mainly at the α-carbon atom), whereas the dichlorophenylsilyl group of dichlorophenylsilane adds only, to the end carbon atom of the double bond. The fluorodiphenylsilyl group of fluorodiphenylsilane adds to almost equal extents at both carbon atoms of the vinyl group of styrene. 3. In high-temperature condensation with chlorobenzene the replacement of the chlorine atoms of dichlorophenylsilane by fluorine atoms leads to a reduction in the ratio of condensation and reduction products.

Asymmetric synthesis of amino acids by catalytic reduction of azalactones of substituted acylaminoacrylic acids: Communication 9. Aminolysis of 4-isopropyl-5-oxazolones

Abstract: Conclusions1.The aminolysis of 4-isopropyl-5-oxazolones by S-(-)-phenylethylamine in dimethoxyethane (DME) givesα-phenylethylamides of the acylvaline with predominantly RS-configuration. In the presence of Et3N, the fraction of the RS-diastereomer is smaller.2.The replacement of dimethoxyethane by tert-butyl alcohol leads to the formation of the amide with primarily the SS-configuration. The addition of Et3N does not change the ratio of diastereomers.3.On the basis of kinetic data on the racemization and aminolysis, and on the stereochemistry of the latter, the hypothesis has been advanced that the aminolysis proceeds by different mechanisms in DME and t-BuOH: In the DME, the main mechanism is interaction of the carbanion with theα-phenylethylammonium; in the t-BuOH, the neutral oxazolone molecules are subjected to attack by the S-α-phenylethylamine.

Asymmetric reduction of phenylα- andβ-dialkylamino ketones by treatment with optically active organomagnesium compounds

Abstract: 1. Whenα-dimethylaminoacetophenone andβ-dimethylaminopropiophenone are reduced by optically active organomagnesium compounds the asymmetric reduction proceeds with an optical yield of 65–70%. 2. The absolute configuration for the obtained amino alcohols was proposed on the basis of the optical rotation dispersion data.

Hydrogenation of the liquid organic hydrogen carrier compound dibenzyltoluene – reaction pathway determination by 1H NMR spectroscopy

Abstract: The catalytic hydrogenation of the LOHC compound dibenzyltoluene (H0-DBT) was investigated by 1H NMR spectroscopy in order to elucidate the reaction pathway of its charging process with hydrogen in the context of future hydrogen storage applications. Five different reaction pathways during H0-DBT hydrogenation were considered including middle-ring preference (middle-side-side, MSS), side-middle-side order of hydrogenation (SMS), side-ring preference (SSM), simultaneous hydrogenation of all three rings without intermediate formation and statistical hydrogenation without any ring preference. Detailed analysis of the 1H NMR spectra of the H0-DBT hydrogenation over time revealed that the reaction proceeds with a very high preference for the SSM order at temperatures between 120 °C and 200 °C and 50 bar in the presence of a Ru/Al2O3-catalyst. HPLC analysis supported this interpretation by confirming an accumulation of H12-DBT species prior to full hydrogenation to H18-DBT with middle ring hydrogenation as the final step.

Strobilurin biosynthesis in Basidiomycete fungi

Abstract: Strobilurins from fungi are the inspiration for the creation of the β-methoxyacrylate class of agricultural fungicides However, molecular details of the biosynthesis of strobilurins have remained cryptic Here we report the sequence of genomes of two fungi that produce strobilurins and show that each contains a biosynthetic gene cluster, which encodes a highly reducing polyketide synthase with very unusual C-terminal hydrolase and methyltransferase domains Expression of stpks1 in Aspergillus oryzae leads to the production of prestrobilurin A when the fermentation is supplemented with a benzoyl coenzyme A (CoA) analogue This enables the discovery of a previously unobserved route to benzoyl CoA Reconstruction of the gene cluster in A oryzae leads to the formation of prestrobilurin A, and addition of the gene str9 encoding an FAD-dependent oxygenase leads to the key oxidative rearrangement responsible for the creation of the β-methoxyacrylate toxophore Finally, two methyltransferases are required to complete the synthesis

Redistribution reactions in the chemistry of silicon

Abstract: In recent years there has been what could be described as a renaissance in the redistribution reaction, and the growing interest in the chemistry of the metalloids has been partially responsible for this renewed interest. The generality and potential synthetic utility of this reaction in the chemistry of silicon, germanium, tin, boron, and phosphorus has necessitated a better understanding of this type of chemical transformation. With the advancement of modern computation and instrumental analytical techniques, this need is slowly being realized. Of the above mentioned elements, the chemistry of silicon has probably been the most intensely studied during recent years and, thus, it is not surprising that the chemistry of silicon provides the most comprehensive picture of the redistribution reaction. The redistribution reaction has been the subject of recent reviews by Moedritzer'\" and by Lockhart3 which cover quite comprehensively the general application of this reaction to silicon chemistry. In this current brief review, we shall confine our attention to the simplest form of this reaction; namely, that involving the redistribution of monodentate ligands about a central silicon atom.