In this work, a simple and economical procedure for the synthesis of spiro-4H-pyranderivatives has been found through the three-component, one-pot condensation of isatin/acenaphthequinone, malononitrile and different reagents including 1, 3-dicrbonyl compounds, naphthol and 4-hydroxycumarin under thermal and solvent-free conditions in the presence ofFe2O<su...

A cover of a hypergraph is a collection of edges whose union contains all vertices. Let H = (V, E) be a k-uniform, D-regular hypergraph on n vertices, in which no two vertices are contained in more than o(D/e log D) edges as D tends to infinity. Our results include that if k = o(log D), then there is a cover of (1 + o(1))n/k edges, extending the known result that this holds for fixed k. On the ...

A visible-light-promoted chloramination of olefins is reported. N-Chlorosulfonamides serve as both nitrogen and chlorine sources. These reactions provide a simple, efficient, regioselective, and atom-economical method for the preparation of vicinal haloamine derivatives under mild reaction conditions. A variety of olefins were tolerated, and chloramination products were obtained in good yields.

We report here an operationally simple, palladium-catalyzed cyclization reaction of N-aryl imines, affording indoles via the oxidative linkage of two C-H bonds under mild conditions using molecular oxygen as the sole oxidant. The process allows quick and atom-economical assembly of indole rings from inexpensive and readily available anilines and ketones and tolerates a broad range of functional...

A recent breakthrough in primary amine dehydrogenation by an oxidant-free process, and without any hydrogen acceptor, opens the possibility for RCH2NH2/RCN couples to be considered as potential hydrogen energy carriers. Both hydrogenation and dehydrogenation processes can be catalysed by ruthenium complexes under rather mild conditions. This emerging exciting approach could be the starting poin...

We present and analyze a design of an filtering system to block email phishing messages, combining reputation, authentication and classification mechanisms. We present simple economical model and analysis, showing sufficient conditions on the precision of the content-classifier, to make phishing unprofitable.

A metal-free, TBHP-promoted economical route is developed via the sp(2) C-H bond functionalization strategy for the synthesis of indenoquinolinones, 4-azafluorenones and fluorenones. Reactions provided excellent yield of the products under mild conditions. We have successfully synthesized 11H-indeno[1,2-b]quinolin-11-one, an antibacterial agent, in excellent yields.

Among the various maladies of Vata Dosa, Ekangaroga, Khanja, Pangu and Avabahuka resemble the disease of Polio myelitis of modern medicine. This communication makes an Endeavour in finding out the striking similarities between the abnormalities caused by Vata Dosa and the Polio myelitis. This paper has also shown some interest towards the indirect aetiological factors like social and economical...