1073-67-2Relevant articles and documents
Electrooxidative 1,2-Bromoesterification of Alkenes with Acids and N-Bromosuccinimide
Wan, Chao,Song, Ren-Jie,Li, Jin-Heng
, p. 2800 - 2803 (2019)
A simple three-component 1,2-bromoesterification of alkenes with acids and N-bromosuccinimide under electrochemical oxidative conditions is described. This transformation enables the construction of β-bromoalkyl esters via oxidative C-Br/C-O difunctionalization, where a variety of alkenes, including styrenes and cycloolefins, were well tolerated to react efficiently with a wide range of acids, such as aromatic acids, aliphatic acids, and amino acids.
-
Walling,Wolfstirn
, p. 852 (1947)
-
Semihydrogenation of phenylacetylene over nonprecious Ni-based catalysts supported on AlSBA-15
Yang, Lei,Yu, Shiyi,Peng, Chong,Fang, Xiangchen,Cheng, Zhenmin,Zhou, Zhiming
, p. 310 - 320 (2019)
A series of nonprecious monometallic Ni/AlSBA-15 and bimetallic Ni–M (M = Zn, Ga, Cu, or Fe)/AlSBA-15 catalysts were prepared using a urea precipitation method and applied to the semihydrogenation of phenylacetylene. The catalysts were characterized by various techniques, showing that the Ni particle size of catalyst can be tuned by adjusting the Al content, and NiZn and NiGa supported catalysts exhibited geometric and electronic effects that originated from the bimetallic alloy. Among all the catalysts studied, NiZn3/AlSBA-15, with a turnover frequency of 10.89 s?1 comparable to that of precious Pd-based catalysts, presented the highest selectivity to styrene (90.3%) at nearly 100% conversion of phenylacetylene in semibatch operation. This catalyst was further evaluated in a continuous fixed-bed reactor for semihydrogenation of a model C8 aromatic fraction of pyrolysis gasoline (a mixture of phenylacetylene, styrene, ethylbenzene and xylene), which aimed at assessing its practical application of recovering styrene from pyrolysis gasoline. The results showed that at complete conversion of phenylacetylene, the styrene concentration in the product was always kept at a stable level and higher than its initial concentration over 100 h of time on stream, demonstrating high selectivity and good stability of NiZn3/AlSBA-15. Finally, the application of NiZn3/AlSBA-15 was extended to other phenylacetylene derivatives.
Palladium-catalyzed proaromatic C(Alkenyl)-H olefination: Synthesis of densely functionalized 1,3-dienes
Wang, Yu-Chun,Huang, Yen-Hsiang,Tsai, Hung-Chang,Sidick Basha,Chou, Chih-Ming
, p. 6765 - 6770 (2020)
An example of proaromatic C(alkenyl)-H olefination is reported. This protocol utilized a free carboxylic acid as a directing group for C(alkenyl)-H activation of 1,4-cyclohexadiene and coupled with various alkenes. Direct and sequential bisolefinations of proaromatic acids were achieved. The synthetic applicability has been exhibited by [4 + 2] cycloaddition and decarboxylative aromatization of the resulting proaromatic 1,3-dienes. Additionally, several kinetic studies also have been carried out to elucidate the reaction mechanism.
Hashimoto et al.
, p. 518 (1967)
Brown,Sharp
, p. 5851,5854 (1966)
Catalyst-Free Enantiospecific Olefination with In Situ Generated Organocerium Species
Music, Arif,Hoarau, Clément,Hilgert, Nicolas,Zischka, Florian,Didier, Dorian
, p. 1188 - 1192 (2019)
Described is the in situ formation of triorganocerium reagents and their application in catalyst-free Zweifel olefinations. These unique cerium species were generated through novel exchange reactions of organohalides with n-Bu3Ce reagents. The adequate electronegativity of cerium allowed for compensating the disadvantages of both usually functional-group-sensitive organolithium species and less reactive organomagnesium reagents. Exchange reactions were performed on aryl and alkenyl bromides, enabling enantiospecific transformations of chiral boron pinacol esters. Finally, these new organocerium species were engaged in selective 1,2-additions onto enolisable and sterically hindered ketones.
-
DePuy,C.H.,Bishop,C.A.
, p. 2535 - 2537 (1960)
-
Photoredox Catalyzed Sulfonylation of Multisubstituted Allenes with Ru(bpy)3Cl2 or Rhodamine B
Chen, Jingyun,Chen, Shufang,Jiang, Jun,Lu, Qianqian,Shi, Liyang,Xu, Zekun,Yimei, Zhao
supporting information, (2021/11/09)
A highly regio- and stereoselective sulfonylation of allenes was developed that provided direct access to α, β-substituted unsaturated sulfone. By means of visible-light photoredox catalysis, the free radicals produced by p-toluenesulfonic acid reacted with multisubstituted allenes to obtain Markovnikov-type vinyl sulfones with Ru(bpy)3Cl2 or Rhodamine B as photocatalyst. The yield of this reaction could reach up to 91%. A series of unsaturated sulfones would be used for further transformation to some valuable compounds.
Copper-Catalyzed Sulfonylation of Cyclobutanone Oxime Esters with Sulfonyl Hydrazides
Dong, Bingbing,Lu, Jiansha,Bao, Honghao,Zhang, Yuanyuan,Liu, Yingguo,Leng, Yuting
supporting information, p. 3769 - 3776 (2021/07/14)
A copper-catalyzed radical cross-coupling of cyclobutanone oxime esters with sulfonyl hydrazides has been developed. The copper-based catalytic system proved crucial for cleavage of the C-C bond of cyclobutanone oximes and for selective C-S bond-formation involving persistent sulfonyl-metal radical intermediates. This protocol is distinguished by the low-cost catalytic system, which does not require ligand, base, or toxic cyanide salt, and by the use of readily accessible starting materials, as well as broad substrate scope, providing an efficient approach to various diversely substituted cyano-containing sulfones.
Base-Mediated Site-Selective Hydroamination of Alkenes
Koh, Ming Joo,Lee, Boon Chong,Li, Ping,Zhang, Xiaoxiang
supporting information, (2021/12/29)
We present a base-mediated hydroamination protocol, using substoichiometric amounts of a hydrosilane and potassium tertbutoxide, that operates under mild conditions at 30 °C. Many aryl- and heteroatom-substituted olefins as well as arylamines are tolerated, affording the desired products with complete regioselectivity. Preliminary mechanistic investigations reveal a non-radical pathway for hydroamination. A sequential remote hydroamination strategy involving an initial Fe-catalysed olefin isomerisation followed by our base-mediated hydroamination was also developed to directly access-arylamines from terminal aliphatic alkenes.
