1115-11-3Relevant articles and documents
Chromium-Catalyzed Production of Diols From Olefins
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Paragraph 0111, (2021/03/19)
Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.
The bioinspired design of a reagent allows the functionalization of Cα-H of α,β-unsaturated carbonyl compounds via the Baylis-Hillman chemistry under ambient conditions
Singh, Palwinder,Kumar, Arun,Kaur, Sukhmeet,Kaur, Jagroop,Singh, Harpreet
supporting information, p. 2936 - 2939 (2016/02/20)
A rationally designed reagent capable of affecting alkylation at Cα of α,β-unsaturated carbonyl compounds is reported. The reaction proceeded at room temperature without any additives. The pH and H-bond formation during the reaction play a key role in the working of the reagent.
The effect of pH on the formation of aroma compounds produced by heating a model system containing l-ascorbic acid with l-threonine/l-serine
Yu, Ai-Nong,Zhang, Ai-Dong
experimental part, p. 214 - 219 (2011/12/14)
The identification of aroma compounds, formed from the reactions of l-ascorbic acid with l-threonine/l-serine at five different pH values (5.00, 6.00, 7.00, 8.00, or 9.55) and 143 ± 2 °C for 2 h, was performed using a SPME-GC-MS technique, and further use
BIOMIMETIC SYNTHESIS OF BACTERIAL C50 CAROTENOIDS DECAPRENOXANTHIN AND C.p. 450
Ferezou, Jean-Pierre,Julia, Marc
, p. 1277 - 1288 (2007/10/02)
Alkylation of the distal double bond of pseudoionone 4 has been carried out with isoprene epoxide (ZnCl2/MeNO2) leading directly to α-cis 10a, α-trans 10b and γ 10c hydroxyprenylionones.The α-cis and γ-isomers have been converted in few steps into the C50 carotenoids decaprenoxanthin 1 and C.p. 450 3 respectively.
INTERACTIONS OF SINGLET OXYGEN WITH 2,5-DIMETHYL-2,4-HEXADIENE IN POLAR AND NON-POLAR SOLVENTS EVIDENCE FOR A VINYLOG ENE-REACTION
Gollnick, Klaus,Griesbeck, Axel
, p. 3235 - 3250 (2007/10/02)
2,5-Dimethyl-2,4-hexadiene (1) was studied as a singlet oxygen acceptor in various solvents. 1 undergoes concomitantly the three well-known modes of singlet oxygen reactions: (1) the ene-reaction to give the allylic hydroperoxide 3, (2) the (4+2)-cycloaddition to give the endoperoxide 4, and (3) the (2+2)-cycloaddition to give the dioxetane 2.Beyond that (and in contrast to simple olefins), there are (4) "physical" quenching and (5) a "vinylog ene-reaction" to give the twofold-unsaturated hydroperoxide 5.The latter reaction represents a novel mode of singlet oxygen interaction with a substituted 1,3-diene. - Kinetic analysis shows that "physical" quenching, endoperoxide and vinylog ene-product formations proceed with solvent-independent rates; the rates of dioxetane and ene-product formations, however, are solvent-dependent. - A mechanism (Scheme 3) is proposed, according to which endoperoxide formation is due to a concerted singlet oxygen reaction with the s-cis-conformational isomer 1b; with the s-trans-isomer 1a, "physical" quenching and the vinylog ene-reaction proceed via a non-polar singlet diradical intermediate, whereas the ene-product formation occurs via a perepoxide-like transition state.In aprotic solvents, the dioxetane is mainly formed via a "tight-geometry intermediate", in methanolic solution via a solvent-stabilized zwitterion; the latter is also responsible for the formation of the methanol-addition product 6.
