92282-73-0Relevant academic research and scientific papers
Organoselenium-Catalyzed Asymmetric Cyclopropanations of (E)-Chalcones
Chein, Rong-Jie,Cheng, Pei-Tung,Tseng, Yu-Hsun
supporting information, p. 8104 - 8108 (2021/10/25)
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
Stahl, Ingfried,Schomburg, Sabine,Kalinowski, Hans Otto
, p. 2247 - 2260 (2007/10/02)
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.
