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Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained b...

Novel 3-aryl-5-{4-[5-(2-hydroxyphenyl)-1-phenylpyrazolyl]}-2-pyrazolines 2a-g have been prepared by the treatment of 3-(3-aryl-3-oxopropenyl)chromen-4-ones 1a-g with phenylhydrazine in refluxing acetic acid. NMR studies on deuteriochloroform solutions of pyrazolyl-2-pyrazolines 2a-g at different temperatures showed that at room temperature a mixture of diastereomers are present. This diastereoselectivity arises...

Dimethyldioxirane oxidation of exocyclic (E,E)-cinnamylideneketones

http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=11&SID=X22NMCKHdF5lcLIJG6o&page=1&doc=1&colname=WOS ; Exocyclic (E,E)-cinnamylideneketones were oxidized by an excess of isolated dimethyldioxirane (DMDO, in acetone solution) at room temperature, providing diastereomeric mixtures of the α,β:γ,δ-diepoxides. In the case of derivatives bearing an ortho-nitrocinnamylidene moiety,...

Epoxidation of (E,E)-cinnamylideneacetophenones with hydrogen peroxide and iodo...

http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=Refine&qid=9&SID=X22NMCKHdF5lcLIJG6o&page=1&doc=2&colname=WOS ; (E,E)-Cinnamylideneacetophenones 3a–j were epoxidized under mild conditions with Jacobsen’s catalyst 4 and hydrogen peroxide or iodosylbenzene as oxidants. γ,δ-Monoepoxides and a diastereomeric mixture of α,β:γ,δ-diepoxides were obtained in each case, and only the α,β-monoepoxide o...

Epoxidation studies of 2-styrylchromones using Jacobsen’s catalyst and hydrogen...

http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=4&SID=S2NjaL1GBbk143plPl1&page=1&doc=7&colname=WOS ; The epoxidation of 2-styrylchromones 2a-h using Jacobsen’s Mn(III)[salen] complex 1 as catalyst is reported for the first time. Several studies were performed using both hydrogen peroxide and iodosylbenzene as oxidants, in order to obtain the α,β-epoxy-2-styrylchromones 3a-h...

Epoxidation of (E,E)-Cinnamylideneacetophenones Using Salen Mn(III) as Catalyst

Salen Mn(III) complexes are efficient and practical catalysts for the epoxidation of various α,β-unsaturated carbonyl compounds. Among common oxidants used are iodosylbenzene, sodium hipochlorite, oxone, peracids and dimethyldioxirane [1]. Although the epoxidation of cinnamylideneacetophenones have already been reported in literature (by Julia’s epoxidation using hydrogen peroxide as oxidant [2] and by oxidatio...

Epoxidation of 2-Styrylchromone derivatives