61001-54-5Relevant academic research and scientific papers
Rhodium-Catalyzed Aerobic Decomposition of 1,3-Diaryl-2-diazo-1,3-diketones: Mechanistic Investigation and Application to the Synthesis of Benzils
Zhu, Jia-Liang,Tsai, Yi-Ting
, p. 813 - 828 (2020/12/22)
The conversion of 1,3-diaryl-2-diazo-1,3-diketones to 1,2-daryl-1,2-diketones (benzils) is reported based on a rhodium(II)-catalyzed aerobic decomposition process. The reaction occurs at ambient temperatures and can be catalyzed by a few dirhodium carboxylates (5 mol %) under a balloon pressure of oxygen. Moreover, an oxygen atom from the O2 reagent is shown to be incorporated into the product, and this is accompanied by the extrusion of a carbonyl unit from the starting materials. Mechanistically, it is proposed that the decomposition may proceed via the interaction of a ketene intermediate resulting from a Wolff rearrangement of the carbenoid, with a rhodium peroxide or peroxy radical species generated upon the activation of molecular oxygen. The proposed mechanism has been supported by the results from a set of controlled experiments. By using this newly developed strategy, a large array of benzil derivatives as well as 9,10-phenanthrenequinone were synthesized from the corresponding diazo substrates in varying yields. On the other hand, the method did not allow the generation of benzocyclobutene-1,2-dione from 2-diazo-1,3-indandione because of the difficulty of inducing the initial rearrangement.
Non-metal catalytic method for preparing 1,3-diketone compounds based on acetyenic ketone
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, (2020/02/19)
The invention discloses a non-metal catalytic method for preparing 1,3-diketone compounds based on acetyenic ketone. The preparation method is a stepwise method or a one-pot method. The stepwise method comprises the following steps: mixing an acetyenic ketone compound I, a nitrogen-containing aromatic compound II and a No.1 base for a reaction, performing separation and purification to obtain an intermediate product, mixing the intermediate product and a No.2 base for a reaction, and performing separation and purification to obtain the product; and the one-pot method comprises the following steps: firstly mixing an acetyenic ketone compound I and a nitrogen-containing aromatic compound II, adding a No.1 base, performing a reaction for a period of time, adding a No.2 base, continuing a reaction for a period of time, and finally performing separation and purification to obtain the product. The method provided by the invention has mild reaction conditions, simple operation and a higher yield, wherein the yield is generally 80% or more, and the method has greater practical application value in drug synthesis.
Method for synthesizing 1, 3-dicarbonyl compound based on terminal alkyne and acyl halide by one-pot process
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Paragraph 0069-0074; 0102-0104, (2020/07/21)
The invention belongs to the technical field of catalytic synthesis, and discloses a method for synthesizing a 1, 3-dicarbonyl compound by a one-pot process, and the method comprises the following steps: by using simple palladium and copper salts as catalysts, reacting terminal alkyne with acyl halide at 0-80 DEG C for 0.5-12 hours under the action of trifluoromethanesulfonic acid to obtain the 1,3-dicarbonyl compound, wherein the molar ratio of the terminal alkyne to the acyl halide to the palladium salt to the copper salt to the trifluoromethanesulfonic acid is 1 to (1 to 2) to (0.00001 to0.10) to (0.00001 to 0.10) to (0.00004 to 0.40); the catalysts used in the method are common the commercialized palladium salt and copper salt, reagents used in the reaction are commercialized reagents, in addition, the raw materials are cheap and easy to obtain, functional group tolerance is good, reaction conditions are mild, operation is easy and convenient, and atom economy is high.
An effective preparation of both 1,3-diketones and nitriles from alkynones with oximes as hydroxide sources
Chen, Pei,Zhang, Qian-Qian,Guo, Jia,Chen, Lu-Lu,Wang, Yan-Bo,Zhang, Xiao
, p. 6958 - 6966 (2018/10/02)
An effective phosphine-catalyzed protocol has been established for the syntheses of 1,3-diketones and nitriles from alkynones with oximes as hydroxide surrogates. This method features the use of a phosphine catalyst, compatibility with various functional groups and ambient temperature, which makes this approach very practical. A plausible mechanism was proposed.
Asymmetric transfer hydrogenation of unsymmetrical benzils
Zhang, Hao,Feng, Dandan,Sheng, Haibo,Ma, Xuebing,Wan, Jinwei,Tang, Qian
, p. 6417 - 6423 (2014/02/14)
In this paper, the asymmetric transfer hydrogenation of unsymmetrical benzils with m, p-substituents was conducted with a substrate/catalyst molar ratio of 100 at 40°C for 24 h to produce (S,S)-hydrobenzoins in good yields (76.2% to 97.1%) with high diastereomeric (syn/anti = 10.8 to 29.7/1) and enantiomeric purities (86.1%ee syn to 98.9%ee syn). Unfortunately, the unsymmetrical benzils with the o-substituents such as electron-donating (R = CH3, OCH3) and electron-withdrawing groups (R = F, Cl, CF3) resulted in poor yields (0% to 31.2%), even at 40°C for 72 h. These products had inefficient diastereoselectivities (syn/anti = 1.5 to 5.0/1) caused by steric effects. Furthermore, the results of a dynamic-kinetic study were used to propose a plausible reaction pathway of unsymmetrical benzil using 3-methoxy-1,2-diphenyl ethanedione as an example.
PARTICULATE UV PROTECTION AGENT
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, (2010/03/02)
The present invention relates to particulate UV protection agents which are obtainable by hydrothermal treatment of a particulate metal oxide and subsequent application of a manganese oxide coating, and to the preparation and use thereof. The present invention furthermore relates to novel compositions, in particular for topical application, which are intended, in particular, for light protection of the skin and/or hair against UV radiation and free-radical-induced stress, and to the use thereof in the above-mentioned cosmetic application.
Cosmetic/sunscreen compositions containing dibenzoylmethane compounds and dithiolane compound photostabilizers therefor
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, (2010/04/30)
Cosmetic/sunscreen compositions contain a combination of at least one dibenzoylmethane sunscreen compound and a photostabilizing amount of at least one dithiolane compound of formula (I) below:
Cosmetic compositions comprising photostabilized dibenzoylmethane compounds and 2-pyrrolidinone-4- carboxy esters
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, (2010/08/07)
Photostable cosmetic compositions contain, formulated into a cosmetically acceptable vehicle, at least one UV-screening system that includes: (a) at least one dibenzoylmethane compound, and(b) at least one 2-pyrrolidinone-4-carboxy ester compound having the following formula (I): in which: R1 is a linear or branched C1-C20 alkyl radical, andR2 is a linear or branched C1-C20 alkyl radical which optionally includes a C5-C6 ring member, the phenyl radical, the benzyl radical or the phenethyl radical.
Photostable cosmetic compositions comprising dibenzoylmethane/pyrrolidinone compounds
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, (2009/12/05)
Photostable UV-photoprotecting cosmetic sunscreen compositions contain (a) an effective UV-photoprotecting amount of at least one dibenzoylmethane compound sunscreen, (b) an effective radiation-photostablizing amount of at least one pyrrolidinone compound having the formula (I) below: and, advantageously, at least one liquid fatty phase and at least one lipophilic active sunscreen agent of low solubility, formulated into (c) a cosmetically acceptable support therefor.
Photoprotective cosmetic compositions comprising photostabilized dibenzoylmethane compounds and siloxane-containing arylalkyl benzoate amide compounds
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, (2009/01/24)
Photostable, topically applicable cosmetic/dermatological compositions contain at least one dibenzoylmethane sunscreen compound and at least one photostabilizing siloxane-containing arylalkyl amide compound of formula (I) below:
