Aldol reaction

The heterogeneous recyclable catalyst, Cu-Fe hydrotalcite, was synthesized by coprecipitation, activated at 200oC and then successfully applied in Aldol reaction. This procedure also exhibited efficiency in the total synthesis of Abhexone, a flavor with high demand in the food and cosmetic industry.

9p viengels 25-08-2023 6 3   Download

Part 1 of ebook "Advanced organic chemistry - Part B: Reactions and Synthesis" has presents the following content: alkylation of enolates and other carbon nucleophiles; reactions of carbon nucleophiles with carbonyl compounds; functional group interconversion by substitution, including protection and deprotection; electrophilic additions to carbon-carbon multiple bonds; reduction of carbon-carbon multiple bonds, carbonyl groups, and other functional groups;...

644p dieptieuung 19-07-2023 6 2   Download

This work involves a facile synthesis of three (S)-proline-based organocatalysts with C2 symmetry and their effects in enantioselective aldol reaction of acetone with substituted aromatic aldehydes. Moderate enantioselectivities (up to 61% ee) were obtained depending on the nature of the substituents on the aryl ring. Computational calculations at HF/6-31 + G(d) level were employed to underline the enantioselectivity imposed by all the organocatalysts.

58p tudichquannguyet 29-11-2021 7 1   Download

A series of cholesterol and based hydrophobic urea and thiourea compounds were synthesized and successfully used as a cocatalyst for L-proline catalyzed aldol reactions in the presence of water. The anticonfigured products were obtained with good yields (up to 94%), high diastereoselectivities (up to 95:5), and high enantiomeric excesses (up to 93% ee). The successful results for catalytic efficiency of L-proline in the presence of water reveal the importance of the hydrophobic nature of cholesterol and diosgenin parts of thiourea on the reactivity and selectivity in the presence of water.

28p tudichquannguyet 29-11-2021 12 1   Download

The obtained results showed that the heterogeneous acid catalysts as modified-Y zeolites were more effective than the heterogeneous base catalysts as hydrotalcite Mg-Al and MgO-Al2O3 mixed oxides in the aldol condensation reaction of vanillin. The highest conversion of vanillin was 95.5 % when the reaction was carried out at 120 oC in 5 hours, using sulfated Y zeolite. The catalytic activity of copper ion-exchanged Y zeolite is more stable than sulfated Y zeolite with the same reaction conditions.

13p nguaconbaynhay10 19-02-2021 5 2   Download

Ebook Organic chemistry - Second Edition present the content organic structures, determining organic structures, nucleophilic addition to the carbonyl group, delocalization and conjugation, nucleophilic substitution at saturated carbon, review of spectroscopic methods, electrophilic addition to alkenes, electrophilic aromatic substitution, conjugate addition and nucleophilic aromatic substitution, chemoselectivity and protecting groups, reactions of enolates with carbonyl compounds: the aldol and claisen reactions...

1265p kietc58 05-09-2020 37 2   Download

In the last twenty years, microfluidic devices have been employed extensively in organic synthesis as strong tools for performing reactions with safety, high efficiency, high selectivity, low cost, and low environmental impact.

7p viputrajaya2711 22-06-2020 11 0   Download

In search of new ways to improve catalyst design, the current research focused on using quantum mechanical descriptors to investigate the effect of proline as a catalyst for mechanism and rate of asymmetric aldol reaction. A plausible mechanism of reaction between acetone and 4-nitrobenzaldehyde in acetone medium was developed using highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies calculated via density functional theory (DFT) at the 6-31G⁄/ B3LYP level of theory.

9p trinhthamhodang1 14-11-2019 17 0   Download

(bq) part 2 book "organic chemistry" has contents: alkylation of enolates, the aldol and claisen reactions; sulfur, silicon and phosphorus in organic chemistry; saturated heterocycles and stereoelectronics; participation, rearrangement and fragmentation;...and other contents.

270p bautroibinhyen20 06-03-2017 65 6   Download

Named reactions still are an important element of organic chemistry, and a thorough knowledge of such reactions is essential for the chemist. The scientific content behind the name is of great importance, and the names themselves are used as short expressions in order to ease spoken as well as written communication in organic chemistry. Furthermore, named reactions are a perfect aid for learning the principles of organic chemistry. This is not only true for the study of chemistry as a major subject, but also when studying chemistry as a minor subject, e.g.

317p hoanglinh0808 22-07-2013 100 22   Download

The formation of carbon–carbon single bonds is of fundamental importance in organic synthesis. As a result, there is an ever-growing number of methods available for carbon–carbon bond formation. Many of the most useful procedures involve the addition of organometallic species or enolates to electrophiles, as in the Grignard reaction, the aldol reaction, the Michael reaction, alkylation reactions and coupling reactions. Significant advances in both main-group and transition-metal-mediated carbon–carbon bond-forming reactions have been made over the past decade.

10p taisaocothedung 12-01-2013 71 1   Download