728-86-9Relevant academic research and scientific papers
Synthesis, coordination and catalytic use of phosphinoferrocene ligands bearing 6-phospha-2,4,6-trioxaadamantane P-donor moieties
?těpni?ka, Petr,Císa?ová, Ivana,Horky, Filip
, (2021/11/11)
1,1’-Bis(diphenylphosphino)ferrocene (dppf) and structurally related ferrocene bis-phosphines are indispensable ligands for coordination chemistry and catalysis. This contribution focuses on the coordination behaviour and catalytic properties of two dppf congeners bearing 1,3,5,7-tetramethyl-2,4,6-trioxa-8-phosphatricyclo[3.3.1.13,7]decane-8-yl groups (CgP) as the P-donor moieties, viz. Ph2PfcCgP (1) and its semi-homologous counterpart Ph2PfcCH2CgP (2; fc = ferrocene-1,1’-diyl). In reactions with a PdCl2 source, compound 1 produced exclusively the cis-chelate complex [PdCl2(1-κ2P,P’)], while the homologated ligand 2 afforded a complex mixture of compounds which equilibrated upon heating in methanol in favour of the symmetrical dimeric complex trans-[(μ-2)PdCl2]2 as a mixture of racemic and meso isomers. Notably, in aqueous Pd-catalysed cyanation of aryl bromides and Suzuki-Miyaura-type cross-coupling of benzoyl chlorides with boronic acids producing benzophenones, catalysts generated in situ from bis-phosphine 1 and Pd(II) sources were often more active than their counterparts resulting from dppf and 2.
Fe-S Catalyst Generated in Situ from Fe(III)- And S3?--Promoted Aerobic Oxidation of Terminal Alkenes
Ai, Jing-Jing,Huang, Cheng-Mi,Li, Jian,Liu, Bei-Bei,Rao, Weidong,Wang, Fei,Wang, Shun-Yi
supporting information, p. 4705 - 4709 (2021/06/28)
An iron-sulfur complex formed by the simple mixture of FeCl3 with S3?- generated in situ from K2S is developed and applied to selective aerobic oxidation of terminal alkenes. The reaction was carried out under an atmosphere of O2 (balloon) and could proceed on a gram scale, expanding the application of S3?- in organic synthesis. This study also encourages us to explore the application of an Fe-S catalyst in organic reactions.
Photo-induced oxidative cleavage of C-C double bonds of olefins in water
Zhang, Yilan,Yue, Xiaoguang,Liang, Chenfeng,Zhao, Jianming,Yu, Wenbo,Zhang, Pengfei
supporting information, (2021/08/27)
The carbonyl compounds, synthesized by the oxidative cleavage of their corresponding olefins, are of great significance in organic synthesis, especially aryl ketones. We have developed a gentle and effective protocol, using acid red 94 as the organic metal-free photocatalyst, O2 as the oxidant, and water as the solvent. Under visible light irradiation, aryl ketone derivatives were obtained in moderate to excellent yields, showing good economic and environmental advantages.
Selective oxidation of alkenes to carbonyls under mild conditions
Huo, Jie,Xiong, Daokai,Xu, Jun,Yue, Xiaoguang,Zhang, Pengfei,Zhang, Yilan
supporting information, p. 5549 - 5555 (2021/08/16)
Herein, a practical and sustainable method for the synthesis of aldehydes, ketones, and carboxylic acids from an inexpensive olefinic feedstock is described. This transformation features very sustainable and mild conditions and utilizes commercially available and inexpensive tetrahydrofuran as the additive, molecular oxygen as the sole oxidant and water as the solvent. A wide range of substituted alkenes were found to be compatible, providing the corresponding carbonyl compounds in moderate-to-good yields. The control experiments demonstrated that a radical mechanism is responsible for the oxidation reaction.
Synthesis of biaryl ketones and biaryl diketones via carbonylative Suzuki-Miyaura coupling reactions catalyzed by bridged bis(N-heterocyclic carbene)palladium(II) catalysts
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Page/Page column 20; 25-26; 29-30, (2021/12/23)
This disclosure relates to bridged bis(N-heterocyclic carbene)palladium(II) complexes, methods of preparing the complexes, and methods of using the complexes in Suzuki-Miyaura coupling reactions.
Gold complexes of bis-indazole-derived N-Heterocyclic carbene: Synthesis, structural characterizations, and catalysis
Zhang, Hua,Xu, Ting,Li, Dongdong,Cheng, Tao,Chen, Jing,Zhou, Yang
, (2021/02/26)
A novel series of bis Indy-NHC gold complexes have been developed and investigated via a mild Ag-carbene transfer route. The obtained complexes were characterized by NMR spectroscopy and X-ray diffraction analysis. The catalytic property of these gold complexes was further evaluated in the oxidation of benzylic. The gold complex E1 showed a high catalytic activity in the oxidation of various benzylic substrates, resulting in the corresponding carbonyl compounds with excellent yields using TBHP as oxidant.
AIBN initiated functionalization of the benzylic sp3 C[sbnd]H and C[sbnd]C bonds in the presence of dioxygen
Hu, Yingying,Shao, Yu,Zhang, Shuwei,Yuan, Yuan,Sun, Zheng,Yuan, Yu,Jia, Xiaodong
supporting information, (2021/02/01)
A sp3 C[sbnd]H bond functionalization and C[sbnd]C bond cleavage were realized by AIBN/O2 catalyst system, providing a series of benzophenones under mild reaction conditions. The mechanistic study shows that a peroxide intermediate is involved in this transformation, and in the case of diphenylmethanes, the sp3 C[sbnd]C bond is cleaved through the peroxide rearrangement, which might provides a new way to cleave relatively strong C[sbnd]C bond and be applied to more general C[sbnd]C bond activation.
Evaluation of Cyclic Amides as Activating Groups in N-C Bond Cross-Coupling: Discovery of N-Acyl-δ-valerolactams as Effective Twisted Amide Precursors for Cross-Coupling Reactions
Bisz, Elwira,Chen, Hao,Dziuk, B?a?ej,Ejsmont, Krzysztof,Lalancette, Roger,Pyle, Daniel J.,Rahman, Md. Mahbubur,Szostak, Michal,Szostak, Roman,Wang, Qi
, p. 10455 - 10466 (2021/07/31)
The development of efficient methods for facilitating N-C(O) bond activation in amides is an important objective in organic synthesis that permits the manipulation of the traditionally unreactive amide bonds. Herein, we report a comparative evaluation of a series of cyclic amides as activating groups in amide N-C(O) bond cross-coupling. Evaluation of N-acyl-imides, N-acyl-lactams, and N-acyl-oxazolidinones bearing five- and six-membered rings using Pd(II)-NHC and Pd-phosphine systems reveals the relative reactivity order of N-activating groups in Suzuki-Miyaura cross-coupling. The reactivity of activated phenolic esters and thioesters is evaluated for comparison in O-C(O) and S-C(O) cross-coupling under the same reaction conditions. Most notably, the study reveals N-acyl-δ-valerolactams as a highly effective class of mono-N-acyl-activated amide precursors in cross-coupling. The X-ray structure of the model N-acyl-δ-valerolactam is characterized by an additive Winkler-Dunitz distortion parameter ?(τ+χN) of 54.0°, placing this amide in a medium distortion range of twisted amides. Computational studies provide insight into the structural and energetic parameters of the amide bond, including amidic resonance, N/O-protonation aptitude, and the rotational barrier around the N-C(O) axis. This class of N-acyl-lactams will be a valuable addition to the growing portfolio of amide electrophiles for cross-coupling reactions by acyl-metal intermediates.
COMPLEXES OF N-HETEROCYCLIC CARBENES FOR TRANSITION METAL CATALYSIS
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Paragraph 29-30, (2021/07/17)
Described herein is a new class of highly active Pd(II)-NHC complexes bearing anilines as throw-away ligands. These catalysts are well-defined, air- and moisture-stable and can be easily purified by chromatographic techniques. High activity and generality has been exemplified in the Suzuki-Miyaura cross-coupling by C-N, C-O and C-Cl cleavage. Facile syntheses of these catalysts is also described.
Aromatization as an Impetus to Harness Ketones for Metallaphotoredox-Catalyzed Benzoylation/Benzylation of (Hetero)arenes
Chen, Ting-Wei,Cheng, Cheng-Ku,Chiu, Cheng-Chau,Huang, Pin-Gong,Lee, Shao-Chi,Lee, Yi-Hsin,Li, Li-Yun,Liao, Hsuan-Hung,Lin, Heng-Bo,Tsai, Zong-Nan,Tsao, Yong-Ting,Yang, Chung-Hsin
, (2022/01/04)
Herein we report ketones as feedstock materials in radical cross-coupling reactions under Ni/photoredox dual catalysis. In this approach, simple condensation first converts ketones into prearomatic intermediates that then act as activated radical sources for cross-coupling with aryl halides. Our strategy enables the direct benzylation/benzoylation of (hetero)arenes under mild reaction conditions with high functional group tolerance.
