7428-99-1Relevant articles and documents
Conjugated elimination versus [1,2]-Wittig rearrangement of unsaturated diox(ol)anes
Lemiègre, Lo?c,Regnier, Thomas,Combret, Jean-Claude,Maddaluno, Jacques
, p. 373 - 377 (2003)
A set of unsaturated dioxanes and dioxolanes has been prepared in three steps from acetoxy-1-isoprene. When reacted with two equivalents of t-BuLi in THF, these compounds provided, under various conditions, a mixture of two types of 1,3-dienes. The first one, derived from a conjugated elimination reaction resulting in the heterocycles opening, is relatively unstable but could be trapped as an acrylate. The second one resulted probably from a [1,2]-Wittig rearrangement. The competition between these two reactions has been observed for both dioxanes and dioxolanes (but not for acyclic ketals) and is the object of a strong temperature effect, the Wittig rearrangement being favored over the elimination at room temperature. A difference between kinetic and thermodynamic deprotonation sites is proposed to be at the origin of this competition on the base of both experimental and theoretical results.
Efficient and selective oxidation of tertiary benzylic C[sbnd]H bonds with O2 catalyzed by metalloporphyrins under mild and solvent-free conditions
Hu, Meng-Yun,Liu, Lei,Qi, Bei,She, Yuan-Bin,Shen, Hai-Min,Ye, Hong-Liang
, (2020/05/19)
The direct and efficient oxidation of tertiary benzylic C[sbnd]H bonds to alcohols with O2 was accomplished in the presence of metalloporphyrins as catalysts under solvent-free and additive-free conditions. Based on effective inhibition on the unselective autoxidation and deep oxidation, systematical investigation on the effects of porphyrin ligands and metal centers, and apparent kinetics study, the oxidation system employing porphyrin manganese(II) (T(2,3,6-triCl)PPMn) with bulkier substituents as catalyst, was regarded as the most promising and efficient one. For the typical substrate, the conversion of cumene could reach up to 57.6% with the selectivity of 70.5% toward alcohol, both of them being higher than the current documents under similar conditions. The superiority of T(2,3,6-triCl)PPMn was mainly attributed to its bulkier substituent groups preventing metalloporphyrins from oxidative degradation, its planar structure favoring the interaction between central metal with reactants, and the high efficiency of Mn(II) in the catalytic transformation of hydroperoxides to alcohols.
Method for selectively oxidizing cumene compounds
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Paragraph 0097; 0098, (2019/11/21)
The invention relates to a method for selectively oxidizing cumene compounds, and the method comprises the following steps: placing cumene compounds shown in a formula (I), an iron porphyrin catalyst,an oxidant and a dispersant into a ball milling tank, sealing the ball milling tank, performing ball milling for 3 to 24 hours at a rotating speed of 100 to 800 rpm at room temperature, stopping ballmilling once every 1 to 3 hours in the ball milling process, discharging gases in the ball milling tank, finishing the reaction, and performing post-treatment on a reaction mixture to obtain product2-phenyl-2-propanol compound shown in a formula (II); according to the invention, the oxidation conversion of the cumene and derivatives thereof is realized through solid-phase ball milling, the reaction mode is novel, the operation is convenient, and the energy consumption is low; the method needs no organic solvent, thus effectively avoiding the use of toxic and harmful organic solvents and being green and environment-friendly; has low peroxide content and high safety factor, and high 2-phenyl-2-propanol and derivative selectivity and meets the social requirements of the current green chemical process, environmental compatibility chemical process and biological compatibility chemical process.
