Highly Enantioselective Addition of Dialkylzinc to Trifluoroacetophenones, Catalyzed by 1,2-Diamines. Synthesis of Key Fragments of Inhibitors of the Enzyme 11β-HSD1 and Kinetic Analysis of the Process was written by Genov, Miroslav;Martinez-Ilarduya, Jesus M.;Calvillo-Barahona, Mercedes;Espinet, Pablo. And the article was included in Organometallics in 2010.Recommanded Product: Ethyl 4-(2,2,2-Trifluoroacetyl)benzoate The following contents are mentioned in the article:
Chiral diamines derived from (R,R)- or (S,S)-1,2-diphenylethylenediamine and (S)- or (R)-2,2′-bis(bromomethyl)-1,1′-binaphthalene perform very well as catalysts in the enantioselective addition of ZnEt2 and ZnMe2 to trifluoroacetophenones, avoiding reduction products, in contrast to the poor results with amino alcs. Excellent yields (up to 99%) and high enantioselectivity (up to 92%) are achieved with the best ligands. A kinetic study at low temperature (-37°) shows that the reduction reaction rate on ligandless ZnEt2 is negligible (2 orders of magnitude slower) compared to the rate of addition reaction on [ZnR2(N-N)]. Using this new procedure, reported fragments of inhibitors of enzyme 11β-HSD1 that are active against obesity and type 2 diabetes mellitus, as well as new unreported modified fragments of these bioactive mols., were produced efficiently and enantioselectively. This study involved multiple reactions and reactants, such as Ethyl 4-(2,2,2-Trifluoroacetyl)benzoate (cas: 898787-14-9Recommanded Product: Ethyl 4-(2,2,2-Trifluoroacetyl)benzoate).
Ethyl 4-(2,2,2-Trifluoroacetyl)benzoate (cas: 898787-14-9) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Recommanded Product: Ethyl 4-(2,2,2-Trifluoroacetyl)benzoate
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Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics