21298-55-5Relevant articles and documents
Tetraphosphine/palladium-catalyzed Suzuki-Miyaura coupling of heteroaryl halides with 3-pyridine- and 3-thiopheneboronic acid: An efficient catalyst for the formation of biheteroaryls
Wang, Kun,Fu, Qi,Zhou, Rong,Zheng, Xueli,Fu, Haiyan,Chen, Hua,Li, Ruixiang
, p. 232 - 238 (2013)
An easily prepared tetraphosphine N,N,N′,N′- tetra(diphenylphosphinomethyl)-1,2-ethylenediamine (L1) associated with [Pd(η3-C3H5)Cl]2 affords an efficient catalyst for Suzuki-Miyaura coupling of 3-pyridineboronic acid with heteroaryl bromides. Reaction could be performed with as little as 0.02 mol% catalyst and a high turnover number of 2500 is obtained. A wide range of substrates is investigated with satisfactory yields, and good compatibility with aminogroup-substituted pyridines and unprotected indole is exhibited. This protocol can also be applied successfully to the reaction of heteroaryl bromides with 3-thiopheneboronic acid. This Pd-tetraphosphine catalyst efficiently restrains the poisoning effect from heteroaryls, and shows good stability and longevity. Copyright 2013 John Wiley & Sons, Ltd. An easily prepared tetraphosphine L1 was successfully used in Pd catalyzed Suzuki reaction of heteroaryl bromides with 3-pyridineboronic acid. A high turnover number of 2 500 was achieved and a wide range of heteroaryl halides including aminopyridines and indole was tolerated. With this protocol the coupling of 3-thiopheneboronic acid with heteroaryl bromides could also proceed in good yields. This catalyst system efficiently restrained poisoning effect from heteroaryls, and exhibited good stability and longevity. Copyright
Water based surfactant-assisted synthesis of thienylpyridines and thienylbipyridine intermediates
Quagliotto,Barbero,Barolo,Buscaino,Carfora,Prosperini,Viscardi
, p. 468 - 479 (2017)
The connection between heterocyclic systems by forming new C[sbnd]C bond is a relevant topic for the easy preparation of intermediates and functional dyes for technological applications. Several methods were developed in the last decades and the urge for sustainable synthetic chemical methods pushed us to prepare thienylpyridines and two thienylbipyridine ligands by the Suzuki reaction in aqueous CTAB micellar medium and in presence of a Pd catalyst. These intermediates can be found as component of dyes and functional thiophene monomers. Reaction conditions were optimized under both thermal and microwave (MW) activation obtaining good yields (70–93%) using Pd(PPh3)4 as catalyst. Two thienylbipyridine ligands were prepared and the transformation of one of them into a terthiophene-based bipyridine ligand was easily obtained by almost green methods and with very good yield. This clean and sustainable method can be proposed as a green step to obtain intermediates and final dyes for technological applications, such as CO2 reduction, in gram-multigram scale.
Theoretical and experimental characterization of 1,4-N?S σ-hole intramolecular interactions in bioactive N-acylhydrazone derivatives
Pinheiro, Pedro De Sena Murteira,Rodrigues, Daniel Alencar,Alves, Marina Amaral,Tinoco, Luzineide Wanderley,Ferreira, Glaucio Braga,De Sant'Anna, Carlos Mauricio Rabello,Fraga, Carlos Alberto Manssour
, p. 497 - 505 (2018)
Sigma-hole (σ-hole) bonds are interactions that are gaining special attention in medicinal chemistry. This type of interaction, initially assigned to the halogens (group 17 of the periodic table), has been extended to atoms of groups 14, 15 and 16. Sulfur atoms have been outstanding for describing these interactions at the intramolecular level (to induce conformational stability) and the intermolecular level (participating in molecular recognition of bioactive compounds by their respective targets). Thus, this work describes the theoretical and experimental characterization of a 1,4-N?S σ-hole intramolecular interaction in the N-acylhydrazone cardioactive prototype LASSBio-294 (1), which leads to conformational stabilization and has a direct influence on the molecular properties of this inotropic prototype compared to a negative control for the interaction, LASSBio-897 (2), which is the regioisomer at the thiophene ring. Our theoretical results were reached using the B3LYP/6-311G(d) level of theory, including analysis of conformational, orbital and electrostatic properties. We performed experimental studies using IR, Raman, UV and NMR spectroscopies, which corroborated our theoretical data, showing significant differences between LASSBio-294 (1) and LASSBio-897 (2) in relation to the bond strength of the groups involved in the N?S interaction (S-C and NC bonds), the energies of the orbitals associated with the S lone pair (Lp(S)) and the antibonding NC π bond (π?(NC)), as well as the 15N chemical shifts in both systems. Together, our results show how this unusual interaction can influence the molecular properties of some organic compounds.
Palladium-Catalyzed Coupling of Heteroaryl Alkylstannanes with Heteroaryl Halides in the Presence of Silver(I) oxide
Malm, Johan,Bjoerk, Patrick,Gronowitz, Salo,Hoernfeldt, Anna-Britta
, p. 2199 - 2202 (1992)
The Pd-catalyzed coupling of heteroaryl trialkylstannanes with a variety of heteroaryl halides has been shown to be greatly promoted by silver(I) oxide.
Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
supporting information, p. 5022 - 5037 (2021/05/04)
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
Mechanochemical Solvent-Free Catalytic C?H Methylation
Ni, Shengjun,Hribersek, Matic,Baddigam, Swarna K.,Ingner, Fredric J. L.,Orthaber, Andreas,Gates, Paul J.,Pilarski, Lukasz T.
supporting information, p. 6660 - 6666 (2020/12/18)
The mechanochemical, solvent-free, highly regioselective, rhodium-catalyzed C?H methylation of (hetero)arenes is reported. The reaction shows excellent functional-group compatibility and is demonstrated to work for the late-stage C?H methylation of biologically active compounds. The method requires no external heating and benefits from considerably shorter reaction times than previous solution-based C?H methylation protocols. Additionally, the mechanochemical approach is shown to enable the efficient synthesis of organometallic complexes that are difficult to generate conventionally.
N-Heterocarbene Palladium Complexes with Dianisole Backbones: Synthesis, Structure, and Catalysis
Li, Dong-Hui,He, Xu-Xian,Xu, Chang,Huang, Fei-Dong,Liu, Ning,Shen, Dong-Sheng,Liu, Feng-Shou
, p. 2539 - 2552 (2019/06/17)
A series of palladium N-heterocyclic carbenes (NHCs), complexes C1-C5, bearing dianisole backbones and substituted N-aryl moieties have been synthesized and characterized. The electronic effect as well as the steric environment of the NHC ligands has been assessed. The synthesized palladium complexes were applied for Suzuki-Miyaura cross-coupling reactions under aerobic conditions. The relationship between the catalytic structure and catalytic performance was then extensively investigated. Upon optimizing the reaction conditions, the C4 was found to be highly efficient to catalyze the cross-coupling of (hetero)aryl chlorides with (hetero)arylboronic acids at a 0.1 mol % palladium loading.
The Highly Efficient Suzuki–Miyaura Cross-Coupling of (Hetero)aryl Chlorides and (Hetero)arylboronic Acids Catalyzed by “Bulky-yet-Flexible” Palladium–PEPPSI Complexes in Air
Ouyang, Jia-Sheng,Li, Yan-Fang,Huang, Fei-Dong,Lu, Dong-Dong,Liu, Feng-Shou
, p. 371 - 375 (2017/12/15)
A series of Pd–PEPPSI complexes were designed and synthesized. The relationship between catalyst structure and properties was systematically investigated. It was revealed that “bulky-yet-flexible” C3 bearing ancenaphthyl backbone was a highly efficient precatalyst and could be successfully employed in Suzuki–Miyaura reactions of (hetero)aryl chlorides with (hetero)arylboronic acids at a low palladium loading in the presence of a weak inorganic base in air.
One-Pot Palladium-Catalyzed Cross-Coupling Treble of Borylation, the Suzuki Reaction and Amination
Jong, Howard,Eey, Stanley T.-C.,Lim, Yee Hwee,Pandey, Sangeeta,Iqbal, Nurul Azmah Bte,Yong, Fui Fong,Robins, Edward G.,Johannes, Charles W.
supporting information, p. 616 - 622 (2017/02/23)
A methodology for a sequential palladium-catalyzed cross-coupling procedure consisting of borylation, the Suzuki reaction and amination has been developed for the assembly of molecules with multi-aryl backbones. The linchpin of this development is the meta-terarylphosphine ligand, Cy*Phine, which has been employed as an air- and moisture-stable precatalyst, Pd(Cy*Phine)2Cl2, to improve the efficiency of one-pot borylation–Suzuki reactions. Additionally, the reactivity of the Pd-Cy*Phine system could be tuned to furnish a one-pot, borylation–Suzuki reaction–amination (BSA) cross-coupling treble. The methodology successfully integrated complementary conditions for three distinctly different and modular reactions. Average yields of 74–94% could be achieved for each segment that cumulatively afforded 50–84% yield over the entire three-step sequence in a single pot. (Figure presented.).
A segmented flow platform for on-demand medicinal chemistry and compound synthesis in oscillating droplets
Hwang, Ye-Jin,Coley, Connor W.,Abolhasani, Milad,Marzinzik, Andreas L.,Koch, Guido,Spanka, Carsten,Lehmann, Hansjoerg,Jensen, Klavs F.
supporting information, p. 6649 - 6652 (2017/07/10)
We report an automated flow chemistry platform that can efficiently perform a wide range of chemistries, including single/multi-phase and single/multi-step, with a reaction volume of just 14 μL. The breadth of compatible chemistries is successfully demonstrated and the desired products are characterized, isolated, and collected online by preparative HPLC/MS/ELSD.
