16552-52-6Relevant academic research and scientific papers
Highly Stereoregular 1,3-Butadiene and Isoprene Polymers through Monoalkyl- N-Aryl-Substituted Iminopyridine Iron Complex-Based Catalysts: Synthesis and Characterization
Boccia, Antonella Caterina,Guelfi, Massimo,Leone, Giuseppe,Masi, Francesco,Palucci, Benedetta,Pampaloni, Guido,Ricci, Giovanni,Sommazzi, Anna,Zacchini, Stefano,Zanchin, Giorgia
, p. 9947 - 9959 (2021/11/16)
Some novel monoalkyl-N-aryl-substituted iminopyridine iron chloride complexes, differing in the nature of the substituent at the iminic carbon and at the ortho position of the aryl ring, were synthesized and characterized. For one of them, single crystals were obtained, which allowed for the determination of its crystalline structure, in which the iron center is coordinated to the chlorides and to the two nitrogen atoms of the ligand. The coordination around iron is distorted tetrahedral, a coordination mode rarely identified for FeCl2 adducts with bidentate nitrogen ligands. All the complexes were used, in combination with methylaluminoxane, for the polymerization of 1,3-butadiene and isoprene, providing syndiotactic 1,2 poly(1,3-butadiene)s and poly(isoprene)s with a predominantly cis-1,4/3,4 alternating structure, in which short cis-1,4 sequences of three or five units, whose length depends on the nature of the ligand on the iron atom, are present. A detailed NMR characterization (1H-, 13C-, and 2D experiments) of the resultant poly(isoprene)s is reported, and a tentative scheme for the formation of the novel isoprene polymers is proposed.
Cu-Catalyzed C-N Coupling with Sterically Hindered Partners
Modak, Atanu,Nett, Alex J.,Swift, Elizabeth C.,Haibach, Michael C.,Chan, Vincent S.,Franczyk, Thaddeus S.,Shekhar, Shashank,Cook, Silas P.
, p. 10495 - 10499 (2020/10/03)
Copper, an earth-abundant metal, has reemerged as a viable alternative to the versatile Pd-catalyzed C-N coupling. Coupling sterically hindered reaction partners, however, remains challenging. Herein, we disclose the discovery and development of a pyrrole-ol ligand to facilitate the coupling of ortho-substituted aryl iodides with sterically hindered amines. The ligand was discovered through a library screening approach and highlights the value of mining heteroatom-rich pharmaceutical libraries for useful ligand motifs. Further evaluation revealed that this ligand is uniquely effective in these challenging transformations. The reaction enables the coupling of sterically hindered primary and secondary amines, anilines, and amides with broad functional group tolerance.
Experimental and mechanistic insights into copper(ii)-dioxygen catalyzed oxidative: N -dealkylation of N -(2-pyridylmethyl)phenylamine and its derivatives
Wang, Yang,Liu, Haixiong,Zhang, Xiaofeng,Zhang, Zilong,Huang, Deguang
supporting information, p. 9164 - 9168 (2017/11/15)
A di-(2-pyridylmethyl)phenylamine ((PyCH2)2NPh) supported Cu(ii)/O2 catalytic system was explored with the synthesis of pyridylmethyl-based compounds of carboxylate (PyCOOH), amide (PyC(O)NHPh), and imine (PyCHNPh) from the oxidative N-dealkylation of N-(2-pyridylmethyl)phenylamine (PyCH2NHPh) and its derivatives, by means of controlling the addition of a base and/or water to the reaction system under a dioxygen atmosphere at room temperature. Experimental studies showed that the imine and amide species could be precursors in succession in the way to the final oxidation state of carboxylates. A cyclic catalytic mechanism was proposed including the base triggered C-H bond activation of the 2-pyridylmethyl group (PyCH2-) and the intermolecular Cu-OOH α-hydrogen atom abstraction from the coordinated imine substrate (PyCHNPh).
