- Palladium-Catalyzed Decarboxylative Benzylation of Acetylides and Enolates
-
Benzylic alkylation of enolates and acetylides has been achieved through the use of a decarboxylative benzylation strategy. Previous research in this area is often limited by the need for extended conjugation in the electrophiles that are coupled. Herein, we report that the use of 1,1'-bis(diphenylphosphino)ferrocene (dppf) ligand allows the coupling of simple benzyl electrophiles with enolates, while the use of XPhos ligand promotes the decarboxylative couplings of propiolates.
- Torregrosa, Robert R. P.,Mendis, Shehani N.,Davies, Alex,Tunge, Jon A.
-
p. 3205 - 3216
(2018/08/17)
-
- Extractive biocatalysis in the asymmetric reduction of α-alkyl, β-aryl enones by Baker's yeast
-
We prepared various chiral α-alkyl, β-aryl ketones with good to excellent enantiomeric excess through the Baker's yeast asymmetric double-bond reduction of the corresponding α,β-unsaturated substrates adsorbed onto the resin Amberlite XAD-7. This methodology was compatible with substrates bearing both electron-donating and withdrawing groups attached to the aromatic ring. Elongation of the α-alkyl substituent of the starting material strongly affected the reactivity and enantioselectivity of the reaction.
- Silva, Rafaela M.,Okano, Laura T.,Rodrigues, J. Augusto R.,Clososki, Giuliano C.
-
supporting information
p. 939 - 944
(2017/07/11)
-
- Substrate scope and synthetic applications of the enantioselective reduction of α-alkyl-β-arylenones mediated by Old Yellow Enzymes
-
The ene-reductases mediated bioreduction of a selection of open-chain α-alkyl-β-aryl enones afforded the corresponding saturated α-chiral ketones in high yield and optical purity in several cases. The stereo-electronic requirements of the reaction have been investigated, considering the nature and location of substituents on the aromatic ring as well as the steric hindrance at the α-position and adjacent to the carbonyl functionality. The general considerations drawn allow us to guide the design of α,β-unsaturated ketones to be employed as substrates of ene-reductases in future preparative applications. An interesting case of orthogonality between enzyme-based and substrate-based stereocontrol within the highly homologous ene-reductases from Saccharomyces species (OYE1-3) has been reported and rationalized with the help of computational docking studies. Furthermore, to demonstrate the synthetic versatility of the reaction, the key chiral precursors of biologically active compounds such as (2′R)- stenusines and (S)-iopanoic acid were obtained. The very robust protocol allowed us to run the reactions on preparative scale in quantitative yields, with a simple work-up and no chromatographic purification steps. The Royal Society of Chemistry 2013.
- Brenna, Elisabetta,Cosi, Sara Lucia,Ferrandi, Erica Elisa,Gatti, Francesco G.,Monti, Daniela,Parmeggiani, Fabio,Sacchetti, Alessandro
-
supporting information
p. 2988 - 2996
(2013/07/25)
-
- METHOD FOR ESTABLISHING CC BONDS BETWEEN ELECTROPHILIC SUBSTRATES AND ? - NUCLEOPHILES IN NEUTRAL TO ALKALINE AQUEOUS OR ALCOHOLIC SOLVENTS WITHOUT USING A LEWIS OR BRONSTED ACID
-
The invention relates to a method for establishing carbon-carbon bonds by reacting electropohilic substrates that have a solvolysis rate kEtOH (25°C) > 10-6 s-1 and ? compounds. The method is characterized by generating the intermediary carbocations in neutral to alkaline aqueous or alcoholic solvents or solvent mixtures without using a Lewis or Br?nsted acid.
- -
-
Page/Page column 17
(2008/06/13)
-
- Catalyzed Reactions of Enol Ethers with SN1 Active Groups: A Novel Method for the Preparation of α-Alkylated Ketones
-
The performance of tert-alkylations, alkoxyalkylations, and aldehyde enolate allylations proceeding with low catalyst loading (0.1 mol % - 5 mol %) is described. The reactions are complete within short times and can even be performed without solvent and under ambient conditions. The mechanism of the reaction was investigated by deuterium labeling and cross-over studies.
- Gansaeuer, Andreas,Fielenbach, Doris,Stock, Christoph,Geich-Gimbel, Daniel
-
p. 1017 - 1030
(2007/10/03)
-
- Catalyzed Reactions of Enolates and Cations: A Novel Method for Enolate Alkylation
-
The first tertiary alkylations, alkoxyalkylations, and aldehyde enolate allylations are described proceeding with low catalyst loading (0.1 mol % to 5 mol %). The reactions proceed in short times, can be performed without solvent and under ambient conditions.
- Gansaeuer, Andreas,Fielenbach, Doris,Stock, Christoph
-
p. 845 - 848
(2007/10/03)
-