- Organoselenium-catalyzed selectivity-switchable oxidation of β-ionone
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Catalyzed by organoselenium compounds, β-ionone was easily oxidized by H2O2 under mild and clean conditions. We were very surprised to find that the reaction selectivity was switchable by the catalyst. To the best of our knowledge, t
- Yu, Lei,Bai, Zengbing,Zhang, Xu,Zhang, Xiaohong,Ding, Yuanhua,Xu, Qing
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p. 1804 - 1809
(2016/04/05)
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- A production method of β - Ionone epoxide
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The invention discloses a production method of beta-ionone epoxide in the field of flavor production, which comprises the following steps: in a nitrogen protective atmosphere, oxidizing beta-ionone in a solvent by using di(3,5-ditrifluoromethylphenyl)dise
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Paragraph 0020-0023; 0028
(2017/01/26)
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- Organoselenium-catalyzed baeyer-villiger oxidation of α,β-unsaturated ketones by hydrogen peroxide to access vinyl esters
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By carefully screening the organoselenium pre-catalysts and optimizing the reaction conditions, simple dibenzyl diselenide was found to be the best pre-catalyst for Baeyer-Villiger oxidation of (E)-α,β-unsaturated ketones with the green oxidant hydrogen peroxide at room temperature. The organoselenium catalyst used in this reaction could be recycled and reused several times. This new method was suitable not only for methyl unsaturated ketones, but also for alkyl and aryl unsaturated ketones. Therefore, it provided a direct, mild, practical, highly functional group-tolerant process for the chemoselective preparation of the versatile (E)-vinyl esters from the readily available (E)-α,β-unsaturated ketones. A possible mechanism was also proposed to rationalize the activity of the organoselenium catalyst in the presence of hydrogen peroxide in this Baeyer-Villiger oxidation reaction.
- Zhang, Xu,Ye, Jianqing,Yu, Lei,Shi, Xinkang,Zhang, Ming,Xu, Qing,Lautens, Mark
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p. 955 - 960
(2015/03/30)
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- A New General Synthetic Approach to Diterpenes: Application to Syntheses of (+ -)-Taxodione and (+ -)-Royleanone.
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High-pressure Diels - Alder reactions of 1,3,3-trimethyl-2-vinyl-1-cyclohexenes 3a,b,i with substituted 1,4-benzoquinones afford, in good yield, highly functionalized tricyclic ring systems which are found in many classes of naturally occuring terpenes.Notably, the reactions of 3a are highly regio- and stereoselective.Efficient, formal syntheses of antitumor diterpenes (+ -)-taxodione and (+ -)-royleanone are reported, which demonstrate the practical application of this new strategy for the preparation of varied terpene systems.Of particular interest is that the high-pressure reactions are accelerated by mild Lewis acids and the regio- and stereoselectivity of these reactions is also improved under the combined high-pressure / Lewis acid conditions in comparison to the high-pressure conditions alone.Indeed, in the reaction of 3a with 2-methoxy-5-methyl-1,4-benzoquinone, ZnBr2 is required to effect the Diels-Alder reaction even at 12 kbar, and endo adduct 12c is formed stereoselectively in 90percent yield.In contrast, low-temperature Ti(IV)-catalyzed reactions of diene 3a with methoxy-substituted 1,4-benzoquinones at atmospheric pressure regioselectively produce dihydrobenzofurans 19 and 20, apparently via alkylation of the quinone Ti(IV) complex by the diene followed by the ring closure.
- Engler, Thomas A.,Sampath, Umashanker,Naganathan, Sriram,Velde, David Vander,Takusagawa, Fusao
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p. 5712 - 5727
(2007/10/02)
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- Baeyer-Villiger Oxidation of β-Ionone with Surfactant Type Peracid
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Treatment of β-ionone with 3-heptadesylmonoperphthalic acid in emulsion system facilitates Baeyer-Villiger oxidation
- Fujise, Yutaka,Fujiwara, Kenshu,Ito, Yukiko
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p. 1475 - 1476
(2007/10/02)
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