نتایج جستجو برای: o xanthenes

تعداد نتایج: 554472  

2007
Inke Siewert Christian Limberg

The syntheses of two functionalized xanthenes are described which after deprotonation represent ligands for dinuclear metal complexes. For the previously prepared [Xanthdim]H2 – which after deprotonation leads to a ligand with two adjacent β -diiminato binding sites – a significantly improved synthetic procedure is described involving the Pd catalyzed coupling of two diethyl malonate moieties t...

Journal: :iranian journal of catalysis 2014
sobhan rezayati rahimeh hajinasiri zahra erfani saman rezayati saeid afshari-sharifabad

an efficient and simple procedure for the synthesis of 1,8-dioxo-octahydroxanthenes from the aromatic aldehydes and 5,5-dimethylcyclohexane-1,3-dione (dimedone) in the presence of boric acid [bo3h3 or b(oh)3] as an inexpensive and reusable catalyst is described. the salient features of this methodology are: the elimination of corrosive liquid acids, high yields, simple methodology, short reacti...

Farhad Shirini, Kurosh Rad-Moghadam Tahereh Naghdi

This paper describes the applicability of 1,3-dichloro-5,5-dimethylhydantoin, as a cheap, stable and commercially available catalyst, in the promotion of the synthesis of 1,8-dioxo-octahydro-xanthenes (DOXOs) via the one-pot condensation of aldehydes and cyclic 1,3-dicarbonyl compounds. This novel synthetic method has the advantages of high yields, short reaction times, low cost and av...

Xiaocui Deng Xiaoyun Hu Zhongqiang Zhou,

A simple and environmentally benign procedure for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes by a one-pot condensation of 2-naphthol with aromatic aldehyde in the presence of [Et3NH][HSO4] as an acidic ionic liquid catalyst under solvent-free conditions has been developed. The reaction work-up is very simple and the catalyst can be easily separated from the reaction mixture and reused s...

Farhad Shirini, Kurosh Rad-Moghadam Tahereh Naghdi

This paper describes the applicability of 1,3-dichloro-5,5-dimethylhydantoin, as a cheap, stable and commercially available catalyst, in the promotion of the synthesis of 1,8-dioxo-octahydro-xanthenes (DOXOs) via the one-pot condensation of aldehydes and cyclic 1,3-dicarbonyl compounds. This novel synthetic method has the advantages of high yields, short reaction times, low cost and av...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید