Search results for "synthesis"
showing 10 items of 2844 documents
Inside Cover: Regioselective Metal‐ and Reagent‐Free Arylation of Benzothiophenes by Dehydrogenative Electrosynthesis (Angew. Chem. Int. Ed. 40/2018)
2018
Selective oxidation of ethane: Developing an orthorhombic phase in Mo–V–X (X=Nb, Sb, Te) mixed oxides
2009
Abstract Mo–V–X (X = Nb, Sb and/or Te) mixed oxides have been prepared by hydrothermal synthesis and heat-treated in N2 at 450 °C or 600 °C for 2 h. The calcination temperature and the presence or absence of Nb determines the nature of crystalline phases in the catalyst. Nb-containing catalysts heat-treated at 450 °C are mostly amorphous solids, while Nb-free catalysts heat-treated at 450 °C and samples treated at 600 °C clearly contain crystalline phases. TPR-H2 experiments show higher H2-consumption on catalysts with amorphous phases. Catalytic results in the oxidative dehydrogenation of ethane indicate that the selective production of the olefin is strongly related to the development of …
Electrosynthesis of Poly(alanine)-Like Peptides in Concentrated Alanine Based Electrolytes, Characterization Coupled to DFT Study and Application to …
2014
The anodic oxidation of concentrated l-alanine on smooth electrodes such as platinum and glassy carbon electrodes was studied. Contrary to the previous studies performed up to now with diluted l-alanine, the electrochemical process generated here results in a completely different situation. The oxidation on smooth platinum was carried out by electrochemical quartz crystal microbalance (EQCM) coupled to cyclic voltammetry technique. The effects of concentration, scan rate, and pH (zwitterion at pH = 6 and alkaline media at pH = 13) on potential values were examined. Glassy carbon and smooth gold electrodes showed the same behavior as on smooth platinum electrode. Spectroscopic analysis such …
ChemInform Abstract: Microwave-Assisted Organocatalytic Enantioselective Intramolecular Aza-Michael Reaction with α,β-Unsaturated Ketones.
2012
The combination of an epi-hydroquinine catalyst and pentafluoropropionic acid accelerates the process.
ChemInform Abstract: Intramolecular Michael Reaction of tert-Butylsulfinyl Ketimines: Asymmetric Synthesis of 3-Substituted Indanones.
2012
The reaction proceeds in the presence of the Ruppert—Prakash reagent (Tms-CF3) with either TBAT or TBAF as a base.
ChemInform Abstract: Renaissance of Electrosynthetic Methods for the Construction of Complex Molecules
2014
Current affairs: Efficient N,N dimerization by using an electric current is a recent powerful example of preparative electrosynthesis where conventional reagents fail. The general and practical nature of this method as well as other applications will breathe new life into the electroorganic synthesis of complex molecules.
One-pot synthesis of polyaza[n]naphthalenophanes and polyaza[n]anthracenophanes
1998
Abstract Pernosylated polyaza[n]cyclophanes 13–20 were prepared by a Richman-Atkins modified methodology. Deprotection under mild conditions gave polyaza[n]cyclophanes 21–28 . This methodology allows for the preparation of cyclophanes containing labile C-N bonds.
ChemInform Abstract: Silicateins - A Novel Paradigm in Bioinorganic Chemistry: Enzymatic Synthesis of Inorganic Polymeric Silica
2013
ChemInform Abstract: Enantioselective Mannich Reaction of β-Keto Esters with Aromatic and Aliphatic Imines Using a Cooperatively Assisted Bifunctiona…
2015
The title reaction tolerates aliphatic and aromatic substituents on both reaction partners, affording products (III) as a mixture of inseparable diastereomers with low or without any diastereoselectivity.
Organocatalytic asymmetric addition of naphthols and electron-rich phenols to isatin-derived ketimines: highly enantioselective construction of tetra…
2015
A quinine-derived thiourea organocatalyst promoted the highly enantioselective addition of naphthols and activated phenols to ketimines derived from isatins. The reaction afforded chiral 3-amino-2-oxindoles with a quaternary stereocenter in high yields (up to 99%) with excellent enantioselectivity (up to 99% ee). To the best of our knowledge, this transformation is the first highly enantioselective addition of naphthols to ketimines