53423-25-9Relevant academic research and scientific papers
Heterobimetallic Pd/Mn and Pd/Co complexes as efficient and stereoselective catalysts for sequential Cu-free Sonogashira coupling–alkyne semi-hydrogenation reactions
Baweja, Saral,Clauss, Reike,Gelman, Dmitri,Hey-Hawkins, Evamarie
, p. 1344 - 1356 (2022/02/03)
A series of heterobimetallic PdII/MII complexes (MII = Mn, Co) were synthesised and tested as precatalysts for sequential Sonogashira coupling–alkyne semi-hydrogenation reactions to form Z-aryl alkenes. The carbometalated heterobimetallic PdII/CoII complex CoPdL3′ demonstrated an apparent cooperative effect compared to the corresponding monometallic counterparts. This compound was identified as a potent single-molecule catalyst for the one-pot Cu-free Sonogashira coupling of aryl bromides with terminal alkynes followed by chemo- and stereoselective semi-hydrogenation of the alkyne intermediate using NH3·BH3 as a hydrogen source. Furthermore, different aromatic substrates have been tested to show the generality of the reaction for the synthesis of Z-alkenes, including biologically active combretastatin A-4. In addition, the homogeneous nature of the catalytically active species was demonstrated.
The two faces of platinum hydrospirophosphorane complexes—Not only relevant catalysts but cytotoxic compounds as well
Skar?yńska, Anna,Kowalczyk, Marta,Majchrzak, Mariusz,Pi?tka, Marta,Augustyniak, Adam W.,Siczek, Mi?osz,W?odarczyk, Kinga,Simiczyjew, Aleksandra,Nowak, Dorota
, (2021/12/08)
Platinum complexes [PtCl2(L)] L = L1, L2 with symmetrical HP (OCH2CMe2NH)2 (L1) and unsymmetrical HP(OCMe2CMe2O)(OCH2CMe2NH) (L2) hydrospirophosphorane (HSP) ligands were demonstrated to play a dual role of catalysts and cytotoxic compounds as well. The structure of new complex [PtCl2(L2)] was confirmed by physicochemical and spectroscopic methods, as well as single X-ray diffraction studies for [PtCl2{P (OCMe2CMe2O)(OCH2CMe2NH2)}]. HSP ligand coordinated to the platinum center in bidentate κ2-P,NH2 chelating mode of fashion. Both complexes were found to exhibit catalytic activity for Heck cross-coupling reactions of iodobenzene with substituted styrenes, with good conversion and yield of stilbenes. Moreover, complexes have been applied as excellent catalysts for highly regioselective hydrosilylation of aromatic and aliphatic terminal olefins, and acetylenes terminal and internal as well. On the other hand, the preliminary biological studies revealed that in the presence of foretinib, drug candidate in clinical trials for the treatment of cancer, platinum complexes revealed increased synergistic effect and efficiently decreased the number of viable cells of triple negative breast cancer MDA-MB-231 cell line.
Dinuclear cobalt complex-catalyzed stereodivergent semireduction of alkynes: Switchable selectivities controlled by H2O
Chen, Ke,Zhu, Hongdan,Li, Yuling,Peng, Qian,Guo, Yinlong,Wang, Xiaoming
, p. 13696 - 13705 (2021/11/16)
Catalytic semireduction of internal alkynes to alkenes is very important for organic synthesis. Although great success has been achieved in this area, switchable Z/E stereoselectivity based on a single catalyst for the semireduction of internal alkynes is a longstanding challenge due to the multichemo- and stereoselectivity, especially based on less-expensive earth-abundant metals. Herein, we describe a switchable semireduction of alkynes to (Z)- or (E)-alkenes catalyzed by a dinuclear cobalt complex supported by a macrocyclic bis pyridyl diimine (PDI) ligand. It was found that cis-reduction of the alkyne occurs first and the Z-E alkene stereoisomerization process is formally controlled by the amount of H2O, since the concentration of H2O may influence the catalytic activity of the catalyst for isomerization. Therefore, this protocol provides a facile way to switch to either the (Z)- or (E)-olefin isomer in a single transformation by adjusting the amount of water.
Biogenic synthesis of Pd-nanoparticles using Areca Nut Husk Extract: a greener approach to access α-keto imides and stilbenes
Dateer, Ramesh B.,Ghosh, Arnab,Hegde, Rajeev V.,Jadhav, Arvind H.,Nizam, Aatika,Patil, Siddappa A.,Peter, Febina
supporting information, p. 16213 - 16222 (2021/09/22)
An eco-friendly green method for a one-step synthesis of palladium nanoparticles and their synthetic utility are reported. Phytochemicals like amines, alcohols, and phenols present in the Areca Nut Husk extract facilitate the reduction of Pd(ii) to Pd(0). The phytochemicals serve as stabilising agents and ligands for palladium reduction and the need for an external ligand is avoided. The Field Emission Scanning Electron Microscopy and Transmission Electron Microscopy of newly synthesized palladium nanoparticles revealed a spherical morphology. The catalytic activity of the nanoparticles was tested for 1,2-difunctionalization of ynamides, Heck coupling, denitrogenative coupling of phenylhydrazine and C-H arylation of indole. Moreover, catalyst recyclability, control experiments, mechanistic elucidation, and gram-scale synthesis are elaborated.
Bimetallic nano alloy architecture on a special polymer: Ni or Cu merged with Pd for the promotion of the Mizoroki–Heck reaction and the Suzuki–Miyaura coupling
Patil, Vijay P,Kashid, Abhijit A,Solanki, Bhanupratap S,Kharul, Ulhas K,Iyer, Suresh
, (2021/02/12)
Abstract: Novel Ni-Pd and Cu-Pd bimetallic nano alloys was designed and heterogenized on the highly robust ABPBI [poly(2,5-benzimidazole)] polymer in high yields using NaBH4 as reducing agent. These were versatile ligand free catalysts for the Mizoroki–Heck reaction and Suzuki–Miyaura coupling. The bimetallic Ni-Pd-ABPBI catalyst for the Mizoroki–Heck reaction of 4-iodo anisole could be recycled 5 times with high yields. Aryl bromides could also be activated for the Mizoroki–Heck reaction using Cu-Pd-ABPBI NP catalysts, with moderate yields. Graphic abstract: Synopsis Novel bimetallic Ni-Pd and Cu-Pd nano alloys, heterogenized on the robust ABPBI [poly(2,5-benzimidazole)] polymer using NaBH4 as reducing agent, is described. These were versatile ligand free, noble metal conservative catalysts, for the Mizoroki–Heck reaction and the Suzuki–Miyaura coupling. Aryl bromides were activated for the Mizoroki–Heck reaction using the Cu-Pd-ABPBI catalyst.[Figure not available: see fulltext.]
Copper(0) nanoparticle catalyzed Z-Selective Transfer Semihydrogenation of Internal Alkynes
Moran, Maria Jesus,Martina, Katia,Bieliunas, Vidmantas,Baricco, Francesca,Tagliapietra, Silvia,Berlier, Gloria,De Borggraeve, Wim M.,Cravotto, Giancarlo
, p. 2850 - 2860 (2021/05/06)
The use of copper(0) nanoparticles in the transfer semihydrogenation of alkynes has been investigated as a lead-free alternative to Lindlar catalysts. A stereo-selective methodology for the hydrogenation of internal alkynes to the corresponding (Z)-alkenes in high isolated yields (86% average) has been developed. This green and sustainable transfer hydrogenation protocol relies on non-noble copper nanoparticles for reduction of both electron-rich and electron-deficient, aliphatic-substituted and aromatic- substituted internal alkynes. Polyols, such as ethylene glycol and glycerol, have been proven to act as hydrogen sources, and excellent stereo- and chemoselectivity have been observed. Enabling technologies, such as microwave and ultrasound irradiation are shown to enhance heat and mass transfer, whether used alone or in combination, resulting in a decrease in reaction time from hours to minutes. (Figure presented.).
An Amine-Assisted Ionic Monohydride Mechanism Enables Selective Alkyne cis-Semihydrogenation with Ethanol: From Elementary Steps to Catalysis
Huang, Zhidao,Wang, Yulei,Leng, Xuebing,Huang, Zheng
supporting information, p. 4824 - 4836 (2021/04/07)
The selective synthesis of Z-alkenes in alkyne semihydrogenation relies on the reactivity difference of the catalysts toward the starting materials and the products. Here we report Z-selective semihydrogenation of alkynes with ethanol via a coordination-induced ionic monohydride mechanism. The EtOH-coordination-driven Cl- dissociation in a pincer Ir(III) hydridochloride complex (NCP)IrHCl (1) forms a cationic monohydride, [(NCP)IrH(EtOH)]+Cl-, that reacts selectively with alkynes over the corresponding Z-alkenes, thereby overcoming competing thermodynamically dominant alkene Z-E isomerization and overreduction. The challenge for establishing a catalytic cycle, however, lies in the alcoholysis step; the reaction of the alkyne insertion product (NCP)IrCl(vinyl) with EtOH does occur, but very slowly. Surprisingly, the alcoholysis does not proceed via direct protonolysis of the Ir-C(vinyl) bond. Instead, mechanistic data are consistent with an anion-involved alcoholysis pathway involving ionization of (NCP)IrCl(vinyl) via EtOH-for-Cl substitution and reversible protonation of Cl- ion with an Ir(III)-bound EtOH, followed by β-H elimination of the ethoxy ligand and C(vinyl)-H reductive elimination. The use of an amine is key to the monohydride mechanism by promoting the alcoholysis. The 1-amine-EtOH catalytic system exhibits an unprecedented level of substrate scope, generality, and compatibility, as demonstrated by Z-selective reduction of all alkyne classes, including challenging enynes and complex polyfunctionalized molecules. Comparison with a cationic monohydride complex bearing a noncoordinating BArF- ion elucidates the beneficial role of the Cl- ion in controlling the stereoselectivity, and comparison between 1-amine-EtOH and 1-NaOtBu-EtOH underscores the fact that this base variable, albeit in catalytic amounts, leads to different mechanisms and consequently different stereoselectivity.
Tandem Acceptorless Dehydrogenative Coupling-Decyanation under Nickel Catalysis
Babu, Reshma,Balaraman, Ekambaram,Midya, Siba P.,Subaramanian, Murugan,Yadav, Vinita
, p. 7552 - 7562 (2021/06/28)
The development of new catalytic processes based on abundantly available starting materials by cheap metals is always a fascinating task and marks an important transition in the chemical industry. Herein, a nickel-catalyzed acceptorless dehydrogenative coupling of alcohols with nitriles followed by decyanation of nitriles to access diversely substituted olefins is reported. This unprecedented C=C bond-forming methodology takes place in a tandem manner with the formation of formamide as a sole byproduct. The significant advantages of this strategy are the low-cost nickel catalyst, good functional group compatibility (ether, thioether, halo, cyano, ester, amino, N/O/S heterocycles; 43 examples), synthetic convenience, and high reaction selectivity and efficiency.
Pd-Catalyzed Cross-Coupling of Organostibines with Styrenes to Give Unsymmetric (E)-Stilbenes and (1 E,3 E)-1,4-Diarylbuta-1,3-dienes and Fluorescence Properties of the Products
Zhang, Zhao,Zhang, Dejiang,Zhu, Longzhi,Zeng, Dishu,Kambe, Nobuaki,Qiu, Renhua
supporting information, p. 5317 - 5322 (2021/06/28)
A general and effective palladium-catalyzed cross-coupling of organostibines with styrenes to give (E)-olefins was disclosed. By the use of an organostibine reagent, this method can produce unsymmetric (E)-1,2-diarylethylenes and (1E,3E)-1,4-diarylbuta-1,3-dienes in good yields with high E/Z selectivity and good functional group tolerance. Resveratrol and DMU-212 were synthesized in high yield. The protocol can be extended to the synthesis of (1E,3E,5E)-1,6-diphenylhexa-1,3,5-triene in 40% yield. Products 5e, 5f, and 7a showed good photoluminescence quantum yields ranging from 72 to 99%.
Mizoroki-Heck Reaction of Unstrained Aryl Ketones via Ligand-Promoted C-C Bond Olefination
Wang, Mei-Ling,Xu, Hui,Li, Han-Yuan,Ma, Biao,Wang, Zhen-Yu,Wang, Xing,Dai, Hui-Xiong
, p. 2147 - 2152 (2021/04/05)
Mizoroki-Heck reaction of unstrained aryl ketone with acrylate/styrene is accomplished via palladium-catalyzed ligand-promoted C-C bond cleavage. Various (hetero)aryl ketones are compatible in the reaction, affording the alkene product in good to excellent yields. Further applications in the late-stage olefination of some drugs, natural products, and fragrance-derived aryl ketones demonstrate the synthetic utility of this protocol. By employing ketone as both the directing group and the leaving group, 1,2-bifunctionalization is achieved via sequential ortho-C-H alkylation/ipso-Heck olefination.
