58949-81-8Relevant articles and documents
All at once arrangement of both oxygen atoms of dioxygen into aliphatic C(sp3)-C(sp3) bonds for hydroxyketone difunctionalization
Qiao, Xiaofeng,Lin, Yuhan,Li, Jiazhen,Ma, Wanhong,Zhao, Jincai
, p. 770 - 777 (2021/04/09)
Both β- and γ- hydroxyketone structures are important units in biologically active molecules, synthetic drugs and fine chemicals. Although there are some routes available for their manufacture from pre-functionalized groups on one or two matrix molecule(s), the approaches to simply and simultaneously deposit two oxygen atoms from dioxygen into two specific C(sp3) positions of pure saturated hydrocarbons have rarely succeeded because they are involved in the targeted activation of three inert C-H σ bonds all at once. Here, we show that a TiO2-CH3CN photocatalytic suspension system enables the insertion of dioxygen into one C(sp3)-C(sp3) bond of strained cycloparaffin derivatives, by which difunctionalized hydroxyketone products are obtained in a one-pot reaction. With the cleavage event to release strain as the directional driving force, as-designed photocatalytic reaction systems show 21 examples of β-hydroxyketone products with 31%–76% isolated yields for three-membered ring derivatives and 5 examples of γ-hydroxyketone products with 30%–63% isolated yields for four-membered ring substrates. 18O isotopic labeling experiments using 18O2, Ti18O2 and intentionally added H218O, respectively, indicated that both oxygen atoms of hydroxyketone products were exclusively from dioxygen, suggesting a previously unknown H+/TiO2-e? catalyzed arrangement pathway of the hydroperoxide intermediate to convert dioxygen into hydroxyketone units. [Figure not available: see fulltext.]
PHOTOOXYGENATION OF 1,2-DIARYLCYCLOPROPANES: FORMATION OF 3,5-DIARYL-1,2-DIOXOLANES VIA PHOTOINDUCED ELECTRON TRANSFER
Mizuno, Kazuhiko,Kamiyama, Nobuhiro,Otsuji, Yoshio
, p. 477 - 480 (2007/10/02)
The photooxygenation of electron-rich 1,2-diarylcyclopropanes such as 1,2-bis(4-methoxyphenyl)cyclopropane and 1-(4-methoxyphenyl)-2-phenyl-cyclopropane in the presence of 9,10-dicyanoanthracene (DCA) as a sensitizer in acetonitrile affords trans- and cis-3,5-diaryl-1,2-dioxolanes in high yields.This photooxygenation is initiated by the electron transfer from 1,2-diarylcyclopropanes to the excited singlet DCA, involving the cation radical of cyclopropanes as a key intermediate.