5293-77-6Relevant academic research and scientific papers
Chemoselective Hydroboration of Propargylic Alcohols and Amines Using a Manganese(II) Catalyst
Brzozowska, Aleksandra,Zubar, Viktoriia,Ganardi, Ruth-Christine,Rueping, Magnus
supporting information, p. 3765 - 3769 (2020/04/15)
The first manganese-catalyzed hydroboration of propargylic alcohols and amines as well as internal alkynes is reported. High regio- and stereoselectivity is achieved by applying 2 mol % of a manganese precatalyst based on the readily accessible bis(imino)pyridine ligand and MnCl2 as metal source. Propargylic alcohols and amines, as well as symmetric internal alkynes, were efficiently converted into the corresponding functionalized alkenes, which can serve as important and valuable intermediates for further synthetic applications such as cross-coupling reactions.
Stereodivergent Synthesis of Alkenylpyridines via Pd/Cu Catalyzed C-H Alkenylation of Pyridinium Salts with Alkynes
Chen, Hua,Haiyan, Fu,Jiang, Weidong,Li, Ruixiang,Li, Shun,Li, Wenjing,Tang, Juan,Xu, Bin,Yuan, Maolin,Zheng, Xueli
supporting information, p. 7814 - 7819 (2020/11/03)
The first Pd/Cu catalyzed selective C2-alkenylation of pyridines with internal alkynes has been developed via the pyridinium salt activation strategy. Importantly, the configuration of the product alkenylpyridines could be tuned by the choice of the proper N-alkyl group of the pyridinium salts, thus allowing for both the Z- and E-alkenylpyridines synthesized with good regio- and stereoselectivity. A plausible mechanism was proposed based on the Hammett study and KIE experiment.
Rhodium(iii)-catalyzed unreactive C(sp3)-H alkenylation of N-alkyl-1H-pyrazoles with alkynes
Li, Tongyu,Liu, Chang,Wu, Shaonan,Chen, Chen C.,Zhu, Bolin
supporting information, p. 7679 - 7683 (2019/08/30)
The first example of pyrazole-directed rhodium(iii)-catalyzed unreactive C(sp3)-H alkenylation with alkynes has been described, which showed a relatively broad substrate scope with good functional group compatibility. Moreover, we demonstrated that the transitive coordinating center pyrazole could be easily removed under mild conditions.
Preparation method of diaryl acetylene compounds
-
Page/Page column 0076; 0077; 0078; 0080; 0113, (2018/05/16)
The invention relates to preparation of an organic compound, and aims to provide a preparation method of diaryl acetylene compounds. The preparation method includes steps of adding associated tribromomethylarene compound and copper in a reactor to perform deoxidizing treatment; dissolving polyamine in a proper amount of anhydrous and oxygen-free solvent, and then adding to the reactor; performingcoupling reaction at 30-80DEG C for 3-12 hours; separating and purifying to obtain diaryl acetylene compounds. The preparation is gentle in synthesis condition and the reaction has good compatibilityto different functional groups; the raw material associated tribromomethylarene compound is convenient to compound and has different substituent groups and variable structure; by adopting one raw material, high-quality product can be obtained through simple treatment, and the output is high; by adopting two different raw materials, the asymmetrical diaryl acetylene compound can be prepared.
Dichotomy of Manganese Catalysis via Organometallic or Radical Mechanism: Stereodivergent Hydrosilylation of Alkynes
Yang, Xiaoxu,Wang, Congyang
supporting information, p. 923 - 928 (2018/01/01)
Herein, we disclose the first manganese-catalyzed hydrosilylation of alkynes featuring diverse selectivities. The highly selective formation of E-products was achieved by using mononuclear MnBr(CO)5 with the arsenic ligand, AsPh3. Whereas using the dinuclear catalyst Mn2(CO)10 and LPO (dilauroyl peroxide) enabled the reversed generation of Z-products in good to excellent stereo- and regioselectivity. Such a way of controlling the reaction stereoselectivity is unprecedented. Mechanistic experiments revealed the dichotomy of manganese catalysis via organometallic and radical pathways operating in the E- and Z-selective routes, respectively.
Direct Synthesis of Symmetric Diarylethynes from Calcium Carbide and Arylboronic Acids/Esters
Fu, Rugang,Li, Zheng
, p. 6648 - 6651 (2017/12/15)
A new methodology for the direct synthesis of symmetric diarylethynes from the reactions of calcium carbide with arylboronic acids/esters is described. Various symmetric diarylethynes were generated from the corresponding arylboronic acids/esters in satisfactory yield by using a palladium catalyst. The advantages of this protocol include the use of a readily available and easy-to-handle acetylene source, and a simple work-up procedure.
Calcium carbide catalytically activated with tetra-: N -butyl ammonium fluoride for Sonogashira cross coupling reactions
Hosseini, Abolfazl,Pilevar, Afsaneh,Hogan, Eimear,Mogwitz, Boris,Schulze, Anne S.,Schreiner, Peter R.
, p. 6800 - 6807 (2017/08/22)
We report a novel method for the direct synthesis of mono- and bis-arylated alkynes utilizing catalytically activated CaC2 as the alkyne component. This fluoride-activated cross coupling reaction provides advantages over existing methods regarding operational simplicity, use of readily available starting materials, and low cost.
Palladium-Catalyzed Domino Process: Synthesis of Symmetrical Diarylalkynes, cis- and trans-Alkenes using Lithium Acetylide as a Synthon
Krishna, Jonnada,Krishna Reddy, Alavala Gopi,Satyanarayana, Gedu
, p. 3597 - 3610 (2016/01/25)
An efficient domino protocol has been developed for the synthesis of symmetrical diarylalkynes. Notably, the method was successful in the presence of a palladium catalyst without the support of a copper co-catalyst. Significantly, the method enabled the use of the commercially available and cheap lithium acetylide ethylenediamine complex as a source of acetylene for the construction of dual C-C bonds, with a wide range of compatibility towards various substituents of the aryl bromides/iodides. Significantly, this protocol was successfully applied to the synthesis of cis- and trans-alkenes in a highly stereoselective manner in a sequential one-pot process.
Coupling reactions of aromatic halides with palladium catalyst immobilized on poly(vinyl alcohol) nanofiber mats
Shao, Linjun,Ji, Weixin,Dong, Pengdu,Zeng, Minfeng,Qi, Chenze,Zhang, Xian-Man
experimental part, p. 267 - 272 (2012/03/26)
Nanoporous poly(vinyl alcohol) (PVA) nanofiber mats prepared by means of electrospinning have been used for the immobilization of palladium catalyst. Thermal treatment of the palladium-loaded PVA nanofiber mats results in the cross-linking of the matrix PVA molecules as well as the reduction of the divalent palladium (Pd2+) into zerovalent palladium (Pd0) species. The palladium oxidation states were examined by X-ray photoelectron spectroscopic (XPS) analysis. The PVA nanofiber morphology was characterized by scanning electron microscopy (SEM). The catalytic activity and recyclability of the prepared heterogeneous palladium catalysts have been evaluated for the Ullmann, Heck-Mizoroki and Sonogashira coupling reactions of aromatic halides. The large structure of the Pd/PVA nanofiber mats can greatly facilitate its separation and recycling, and the high catalytic activity and stability of the prepared Pd/PVA nanofiber mats have been attributed to the chelation of palladium species with the abundant hydroxyl functional groups on the PVA matrix surface area.
Tandem Sonogashira coupling: An efficient tool for the synthesis of diarylalkynes
Novak, Zoltan,Nemes, Peter,Kotschy, Andras
, p. 4917 - 4920 (2007/10/03)
(Chemical Equation Presented) The tandem Sonogashira coupling reaction of aryl halides provides an efficient method for the synthesis of diarylalkynes. Several aryl halides were coupled with 2-methyl-3-butyn-2-ol as acetylene source in the presence of PdCl2(PPh3)2 and CuI. Following the deprotection of the acetylene moiety in the same pot using a strong base, the Sonogashira coupling of a second aryl halide led to the formation of the appropriate diarylakyne. The established protocoll was successfully extended to the preparation of compound libraries.
