No abstract

No abstract

No abstract

A series of densely substituted 2H-chromenes and 2H-thiochromenes were synthesized in good yield through cyanuric chloride-dimethylformamide mediated cleavage of different spiro-4-hydroxychroman-3,1'-cyclopropanes and similar thiochroman analogues. This protocol involves operationally very simple, facile and cost-effective reactions using easily accessible reagents under mild reaction condition with tolerance of a variety of sensitive moieties. Results of steady state and time-resolved absorption and emission spectroscopy highlighted the potential of these compounds as fluorescence probes and designated the suitability for subcellular bioimaging. The prepared 2H-chromenes demonstrated profound cytotoxic activity against MCF-7 cell line. DFT calculations were done on a representative compound where the results indicated promising reactivity of the title compounds as electron-donating dienes. As a continuation, some of these compounds underwent [4 + 2] Diels-Alder cycloaddition with electron-deficient dienophiles in the absence of any activator or catalyst, which provided an easy access to an array of hitherto unreported molecular frameworks related to bioactive cannabinoid skeletons. These newly constructed Diels-Alder adducts also bear substantial antiproliferative properties.

To date, the transformation of organic compounds to nifty chemicals plays a pivotal role in the global industrial market and renewable economy.The substantial attention has been bestowed to the supported Ni catalyst because of their attractive stability in air and excellent catalytic efficacy in various organic transformations.This review article aims to offer a comprehensive review on the remarkable advances in the development of various robust support containing Ni catalysts for efficient organic reactions, such as, Hydrogenation, Oxidation, Coupling, Multicomponent Reactions (MCRs), Amination, Hydration, Polymerization etc. The role of supported Ni catalysts towards different organic reactions is highlighted with its associated mechanism. The role of numerous solid supported Nickel nanoparticles based nontoxic, cheap and reusable catalyst in organic synthesis and their applications towards the green synthesis of various important organic frameworks including biologically active heterocycles has been highlighted in this review. The observed shortcomings and future research perspective are also accentuated.

No abstract

Ac ost-effective,o perationally simple and eco-compatible protocolf or the one-pot synthesis of photochromic pyrans by the reactiono fp ropargyl alcohols as well as propargyl ethers with differently substituted phenols under ambient atmosphere in aqueous mediumh as been developed using b-cyclodextrinh ydrate as an efficient, recyclable ands table catalyst. This is the first report where b-cyclodextrin hydrate acted as acatalyst for an organic transformation but b-cyclodextrin alone failed.

No abstract