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
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.
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.
Redox-Neutral Photocatalytic C?H Carboxylation of Arenes and Styrenes with CO2
Bergonzini, Giulia,Brandt, Peter,Fricke, Florian,Johansson, Magnus J.,K?nig, Burkhard,Schmalzbauer, Matthias,Svejstrup, Thomas D.
supporting information, p. 2658 - 2672 (2020/10/07)
-
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.
