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.

Synthesis of dienic δ-dimethylamino-γ-methyl(phenyl)carbonyl compounds and a study of their valence isomerism employing ultraviolet and infrared spectroscopy

Abstract: 1. Some previously unknown dienic δ-dimethylaminocarbonyl compounds, containing a substituent (Me or Ph) in the γ position, were synthesized. The δ-aminodienone-2-amino-2H-pyran valence isomerization was discovered and studied (via the UV and IR spectra) for the first time on the example of these compounds. 2. The existence of a dynamic equilibrium between both valence isomers was established. The equilibrium is shifted toward the δ-aminodienones with increase in the temperature, and also the dielectric constant of the solvent and its capacity for specific solvation. An especially strong change occurs when the amount of water in organic solvents is increased. 3. The dienic δ-amino-γ-methyl(phenyl)carbonyl compounds exhibit a clearly expressed solvatochromism, the nature of which depends on the valence isomerization. 4. The aggregate state can exert an effect on the existence of the δ-aminodienones as either valence isomer; 6-dimethylamino-3-carbomethoxy-5-methyl-3,5-hexadien-2-one in the crystalline state represents the dienone, while in the molten state it represents the 2Hpyran.

Formal Synthesis of Strobilurins A and X.

Abstract: Known synthetic precursors of strobilurins A and X, i.e., methyl (3Z,5E)-6-aryl-3-methylhexa-3,5-dienoates (aryl is phenyl, 4-methoxyphenyl), were synthesized by highly stereospecific reactions from 2-(2-tert-butyldimethylsilyloxyethyl)- and 2-[2-(4-methoxybenzyloxy)-ethyl]-5-arylpenta-2E,4E-dien-1-ols. These dienols were efficiently dehydroxylated to (1E,3Z)-4-methyl-6-(4-methoxybenzyloxy)hexa-1,3-dienylarenes with their subsequent demethoxyben-zylation to (3Z,5E)-6-aryl-3-methylhexa-3,5-dien-1-ols. The latter through the step of corresponding aryldienals and aryldienoic acids were transformed to the target methyl (3Z,5E)-6-aryl-3-methylhexa-3,5-dienoates, which completes a formal synthesis of strobilurins A and X. Configuration of the C=C bonds of the conjugated aryldiene system is preserved in the considered transformations by 95–97%.

Polymeric Pd catalysts for the reduction of acetamidocinnamic acid azlactone and its solvolysis products

Abstract: Pd complexes have been obtained from linear and cross-linked copolymers ofR,S-, R-, andS-1-(4-vinylphenyl)ethylamine (1) with styrene and divinylbenzene. Reduction of these compounds gave catalysts which were active in the reductive solvolysis of α-acetaminocinnamic acid azlactone (2) and hydrogenation of the solvolysis products α-acetamidocinnamic acid (ACA), its esters, and its 1-phenylethylamide. The catalysts showed no enantioselective properties in the reductive hydrolysis, but were more active than the catalyst obtained in the absence of the polymer (the “monomeric” analog). The use of polymeric catalysts has shown that, in reductive aminolysis, the chiral nucleophile plays the dominant part in determining the stereoselectivity of the reaction, rather than the chiral ligand of the catalytic complex. The polymer matrix stabilizes the low-valent state of the palladium in the complex. In the hydrogenation of ACA and its esters, the catalyst on the cross-linked polymer is much more active than its “monomeric” analog, but showed no enantioselectivity. Hydrogenation of acetamidocinnamic acidR-andS-1-phenylethylamides on a chiral Pd-polymer catalyst occurred with double asymmetric induction.

Selectivity of the generation of 3- and 4-carboxyalkyl radicals from substituted glutaric and adipic acids and their oxidative lactonization

Abstract: 1. The oxidative decarboxylation of acids with carboxyl groups at secondary and tertiary C atoms under the action of the S2O82−- Ag+ and S2O82−-Ag+- Cu2+ systems is at least an order of magnitude faster than that of acids with COOH groups at a primary C atom, as a result of which 3- and 4-carboxyalkyl radicals with the general formula R'RĊ(CH2)nCOOH (R is alkyl or phenyl, R′ is H or alkyl, n=2 or 3) are generated with > 90% selectivity from 2-substituted glutaric and adipic acids. 2. The 3- and 4-carboxyalkyl radicals are completely or partially converted under their generation conditions into lactones. The selectivity of the oxidative lactonization increases from 0.30 to 0.97 along the series of radicals C2H5ĊH(CH2)3COOH, C2H5ĊH(CH2)2COOH, ĊH2(CH2)3COOH, ĊH2(CH2)2COOH, (CH3)2Ċ(CH2)2-COOH, and C2H5ĊH(CH2)2COOH in the case of the S2O82−-Ag+ system and from 0.72 to 1 along this series in the case of the S2O82−- Ag+- Cu2+ system.

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.