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Upstream product

• 13565-43-0 1-(2-methyl-phenyl)-3-phenyl-2-propen-1-one 
• 41570-67-6 1-benzyltetrahydro-1H-thiophen-1-ium bromide 
• 577-16-2 2-Methylacetophenone 
• 13565-43-0 (2E)-1-(2-methylphenyl)-3-phenyl-2-propenyl-1-one 
• 100-39-0 benzyl bromide 
• 100-52-7 benzaldehyde 

Relevant academic research and scientific papers

Organoselenium-Catalyzed Asymmetric Cyclopropanations of (E)-Chalcones

We report a new class of chiral tetrahydroselenophene based on (S)-diphenyl(tetrahydroselenophen-2-yl)methanol, which was prepared from (R)-3-(3-bromopropyl)-2,2-diphenyloxirane and sodium selenide. These chiral tetrahydroselenophene-based compounds were used to catalyze asymmetric cyclopropanation reactions; the selenonium ylide intermediates formed from these selenium-containing catalysts and benzyl bromide efficiently react with (E)-chalcones to give various cyclopropanes (27 examples) with excellent enantioselectivities of ≤99% ee and are the first examples of organoselenium-catalyzed asymmetric cyclopropanations.

Generation of Diastereomeric Cyclopropanes from Benzylidenesulfuranes and Chalcones

The reaction of the benzylidenesulfuranes 2, available by deprotonation of the benzylsulfonium bromides 1, with chalcones 3, which are substituted in the aroyl part, leads to the stereoisomeric cyclopropanes 4 and 5.The stereochemistry of 4 and 5 is elucidated by spectroscopy.A carbenic mechanism of formation of 4 and 5 is excluded experimentally.