Silica gel has been used for synthesis of biscoumarin derivatives starting from 4-hydroxycoumarin and aryl aldehydes. The reaction conditions are completely in agreement with green chemistry principles including sing water as media and a recyclable and safe catalyst. This method is also simple and inexpensive and leads to high yield of products in short reaction times.

A visit to Bristol is for me always a delightful experience, even when the pleasure is somewhat tempered by the responsibility of having to talk for a short time to such a distinguished audience as that I see before me today. When I come to Bristol I feel I am entering a city with all the qualities of an old capital of the west country. Its history goes back into the distant past, and the story...

a very efficient one-pot three-component synthesis of pyran derivatives has been improved by condensation of aldehydes and malononitrile with dimedone under 80 °c using sucrose as natural and biodegradable catalyst in water. this method offers some advantages including inexpensive, high to quantitative yields, short reaction time, and easy work-up. therefore, this methodology is entirely green ...

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...

Low impact development (LID) is generally regarded as a more sustainable solution for urban stormwater management than conventional urban drainage systems. However, its effects on urban flooding at a scale of urban drainage systems have not been fully understood particularly when different rainfall characteristics are considered. In this paper, using an urbanizing catchment in China as a case s...

Blu Homes, an innovative housing company based in the Boston, is looking forward to having the opportunities to expand its customer base on the West Coast. The company sells durable, energy-efficient prefabrication homes and has several million dollars of revenue annually. Blu Homes has a concrete mission to build super-efficient prefabrication green homes by leveraging their leading-edge techn...

A simple, mild and high efficient procedure for one pot three component synthesis of 2-amino 4-H chromene derivatives was studied. The reaction was performed in water using aryl aldehydes, malononitrile and resorcinol, phloroglucinol or naphthole in the presence of N-methyl D-glucamine (Meglumine) as a green high efficient catalyst. The reaction was studied in thermal, microwave (MW) and ultras...

a mild, efficient and fast method for the oxidation of alcohols and trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers to their corresponding carbonyl compounds using cro3 in the presence of rice husk ash (rha) is reported. all reactions were performed at room temperature in high to excellent yields. a new, efficient and green catalyst, heterogeneous reaction conditions, easy work-up of...

A green and convenient méthode for the synthesis of  a variety of xanthene derivatives by condensation reaction between aldehydes and β-naphthol or dimedone in an micellar solution of sodium dodecylphosphonate is described. This method offers several advantages, such as using of a cheap and environmentally benign reaction media, low loadings of sodium dodecylphosphonate as catalyst and...

In this study, a one-pot and efficient method is reported for the synthesis of symmetrical disulfides from alkyl halides in the present of sulfur and 1-butyl-3-methylimidazolium hydroxide as a basic reagent and phase transfer catalyst. The reaction proceeded very fast and afforded the desired products in moderate to excellent isolated yields.