1746-23-2Relevant academic research and scientific papers
Functionalized styrene synthesis via palladium-catalyzed C[sbnd]C cleavage of aryl ketones
Dai, Hui-Xiong,Wang, Xing,Wang, Zhen-Yu,Xu, Hui,Zhang, Xu
, (2022/03/31)
We report herein the synthesis of functionalized styrenes via palladium-catalyzed Suzuki–Miyaura cross-coupling reaction between aryl ketone derivatives and potassium vinyltrifluoroborate. The employment of pyridine-oxazoline ligand was the key to the cleavage of unstrained C[sbnd]C bond. A variety of functional groups and biologically important moleculars were well tolerated. The orthogonal Suzuki–Miyaura coupling demonstrated the synthetic practicability.
Nickel-Catalyzed Reductive Cross-Coupling of Aryl Bromides with Vinyl Acetate in Dimethyl Isosorbide as a Sustainable Solvent
Su, Mincong,Huang, Xia,Lei, Chuanhu,Jin, Jian
supporting information, p. 354 - 358 (2022/01/15)
A nickel-catalyzed reductive cross-coupling has been achieved using (hetero)aryl bromides and vinyl acetate as the coupling partners. This mild, applicable method provides a reliable access to a variety of vinyl arenes, heteroarenes, and benzoheterocycles, which should expand the chemical space of precursors to fine chemicals and polymers. Importantly, a sustainable solvent, dimethyl isosorbide, is used, making this protocol more attractive from the point of view of green chemistry.
Ligand-free (: Z)-selective transfer semihydrogenation of alkynes catalyzed by in situ generated oxidizable copper nanoparticles
Grela, Karol,Kusy, Rafa?
supporting information, p. 5494 - 5502 (2021/08/16)
Herein, we present (Z)-selective transfer semihydrogenation of alkynes based on in situ generated CuNPs in the presence of hydrogen donors, such as ammonia-borane and a green protic solvent. This environmentally friendly method is characterized by operational simplicity combined with high stereo- and chemoselectivity and functional group compatibility. Auto-oxidation of CuNPs after the completion of a semihydrogenation reaction results in the formation of a water-soluble ammonia complex, so that the catalyst may be reused several times by simple phase-separation with no need for any special regeneration processes. Formed NH4B(OR)4 can be easily transformed back into ammonia-borane or into boric acid. In addition, a one-pot tandem sequence involving a Suzuki reaction followed by semihydrogenation was presented, which allows minimization of chemical waste production.
Method for selectively synthesizing cis-trans-olefin by catalytic alkyne semi-reduction through water-hydrogen-supplying palladium
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Paragraph 0120; 0137-0140, (2021/10/30)
The method comprises the following steps: TEOA, NaOAc, a catalyst, water and alkyne are subjected to a reduction reaction of alkyne in an organic solvent to react to form cis-olefin. Ligand t-Bu2 PCl, The catalyst, water and the alkyne are subjected to a reduction reaction of alkyne in an organic solvent to react to form a trans-olefin. The reactor for the reduction reaction is a sealed pressure-resistant reactor, the temperature of the reduction reaction is 120 - 150 °C, and the reduction reaction time is 20 - 40h. The amount of the catalyst used is 5 - 20% of the molar amount of alkyne, and the amount of water is 10 - 50 times of the molar amount of alkyne. The ligand is used in an amount 2-5 times the molar amount of catalyst. In the invention, the catalyst system has extremely high chemical reaction and stereoselectivity, and cis or trans olefinic products can be synthesized at high yield. The catalytic system has strong universality on substrates, and alkynes containing various functional groups can efficiently carry out high-selectivity reduction reaction.
In-situ facile synthesis novel N-doped thin graphene layer encapsulated Pd@N/C catalyst for semi-hydrogenation of alkynes
Lin, Shanshan,Liu, Jianguo,Ma, Longlong,Sun, Jiangming
, (2021/12/03)
Transition metal-catalyzed semi-hydrogenation of alkynes has become one of the most popular methods for alkene synthesis. Specifically, the noble metal Pd, Rh, and Ru-based heterogeneous catalysts have been widely studied and utilized in both academia and industry. But the supported noble metal catalysts are generally suffering from leaching or aggregation during harsh reaction conditions, which resulting low catalytic reactivity and stability. Herein, we reported the facile synthesis of nitrogen doped graphene encapsulated Pd catalyst and its application in the chemo-selective semi-hydrogenation of alkynes. The graphene layer served as “bulletproof” over the active Pd Nano metal species, which was confirmed by X-ray and TEM analysis, enhanced the catalytic stability during the reaction conditions. The optimized prepared Pd@N/C catalyst showed excellent efficiency in semi-hydrogenation of phenylacetylene and other types of alkynes with un-functionalized or functionalized substituents, including the hydrogenation sensitive functional groups (NO2, ester, and halogen).
Reductive hydrobenzylation of terminal alkynesviaphotoredox and nickel dual catalysis
Zhao, Xian,Zhu, Shengqing,Qing, Feng-Ling,Chu, Lingling
supporting information, p. 9414 - 9417 (2021/09/22)
A photoredox/nickel dual catalyzed reductive hydrobenzylation of alkynes and benzyl chlorides by employing alkyl amines as a stoichiometric reductant is described. This synergistic protocol proceedsviaMarkovnikov-selective migratory insertion of an alkyne into nickel hydride, followed by cross-coupling with benzyl chloride, providing facile access to important 1,1-disubstituted olefins. This reaction enables the generation of nickel hydride by utilizing readily available alkyl amines as the hydrogen source. The mild conditions are compatible with a wide range of aryl and alkyl alkynes as well as chlorides.
KO-t-Bu Catalyzed Thiolation of β-(Hetero)arylethyl Ethers via MeOH Elimination/hydrothiolation
Shigeno, Masanori,Shishido, Yoshiteru,Hayashi, Kazutoshi,Nozawa-Kumada, Kanako,Kondo, Yoshinori
, p. 3932 - 3935 (2021/08/24)
Herein, we describe a KO-t-Bu catalyzed thiolation of β-(hetero)arylethyl ethers through MeOH elimination to form (hetero)arylalkenes followed by anti-Markovnikov hydrothiolation to afford linear thioethers. The system works well with a variety of β-(hetero)arylethyl ethers, including electron-deficient, electron-neutral, electron-rich, and branched substrates and a range of aliphatic and aromatic thiols.
Nickel-Catalyzed Ligand-Free Hiyama Coupling of Aryl Bromides and Vinyltrimethoxysilane
Wei, Shichao,Mao, Yongjun,Shi, Shi-Liang
supporting information, p. 1670 - 1674 (2021/02/26)
We herein disclose the first Ni-catalyzed Hiyama coupling of aryl halides with vinylsilanes. This protocol uses cheap, nontoxic, and stable vinyltrimethoxysilane as the vinyl donor, proceeds under mild and ligand-free conditions, furnishing a diverse variety of styrene derivatives in high yields with excellent functional group compatibility.
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.
Electrochemical fluorosulfonylation of styrenes
Jiang, Yi-Min,Wu, Shao-Fen,Yan, Hong,Ye, Ke-Yin,Yu, Yi,Yuan, Yaofeng
supporting information, p. 11481 - 11484 (2021/11/16)
An environmentally friendly and efficient electrochemical fluorosulfonylation of styrenes has been developed. With the use of sulfonylhydrazides and triethylamine trihydrofluoride, a diverse array of β-fluorosulfones could be readily obtained. This reaction features mild conditions and a broad substrate scope, which could also be conveniently extended to a gram-scale preparation.
