4H-1,4-Benzothiazines and its derivatives are potential pharmacologically and industrially useful agents. They were prepared by condensation followed by oxidative cyclization of 2-amino-4,6-dimethylbenzenethiol with varied βdiketones/β-ketoesters in dimethyl sulfoxide. On refluxing with H2O2 in glacial acetic acid, the substituted 4H-1,4Benzothiazines yielded 4H-1,4-Benzothiazine-1,1-dioxides (...

The double Reformatsky reaction, tandem addition of two molecules of zinc alkanoate to a carbonyl compound, and its synthetic application to a series of δ-hydroxy-β-ketoesters has been developed. The key to accelerate the double Reformatsky reaction is considered to be a complex-induced proximity effect of the in situ generated zinc alkoxide coordinated with the pyridyl group of the substrate o...

a highly efficient, simple and clean solvent-free protocol for the synthesis of polyhydroquinolines is described. the one-pot multi-component condensation reaction between arylaldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione), β-ketoesters and ammonium acetate in the presence of catalytic amount of (2.5 mol%) melamine trisulfonic acid (mtsa) as a recyclable, green and attractive sulfonic ...

Simple and effective multi-component one-pot aldol addition/protection reactions of β-ketoesters to a series of aldehydes in the presence Me(3)SiCl and i-Pr(2)EtN have been described. The analysis of the scope of the reaction revealed a dramatic dependence of the reactivity on the substrates used. Thus the effect of a catalytic amount of DMF and different reaction conditions was widely investig...

A new strategy for the functionalization of sterically hindered terminal olefins is reported. Alkenes bearing quaternary carbons at the allylic or homoallylic position are readily oxidized to the corresponding aldehydes by palladium/copper/nitrite catalysis. A broad range of functional groups including esters, nitriles, silyl ethers, vinylogous esters, ketones, lactones, and β-ketoesters are to...

The gold-catalyzed intermolecular hydroalkylation of olefins with β-ketoesters represents a conceptually attractive and useful synthetic tool; however, it has been scarcely applied, remaining a challenge for chemists. The aim of the current study was to investigate the addition of these 1,3-diketo-compounds to alkenes under gold catalysis conditions, in order to establish the electronic and ste...

Transesterification, one of the most effective methods for ester synthesis, is usually conducted under acid or basicconditions. Although quite a few methods have been reported for transesterification, they are not general as far asp-ketoesters are concerned. Some of these methods used toxic, expensive reagents and in relatives large amount. Inthis research, transesterification reaction six type...

Usually in order to obtain out-of-plane sub­stituted phthalocyanine complexes of zirconium and hafnium (PcML2), the reaction substitution chlorine atoms dichloridophthalocyaninates PcMCl2 is used. How­ever, this method has some limitations because during reaction, hydrogen chloride released, which can initiate hydrolysis starting compounds sensitive an acidic environment, particular, β-ketoeste...