4385-61-9Relevant academic research and scientific papers
Photostable ester-substituted bis-cyclometalated cationic iridium(III) complexes for continuous monitoring of oxygen
Liu, Chun,Yu, Hongcui,Xing, Yang,Gao, Zhanming,Jin, Zilin
, p. 734 - 741 (2015)
Three bis-cyclometalated cationic Ir(iii) complexes Ir1, Ir2 and Ir3 with an ester substituent at the 4-position of the phenyl ring on the 2-phenylpyridine (ppy) have been synthesized and fully characterized. The emission maxima of ester-substituted Ir(ii
Unified Protocol for Fe-Based Catalyzed Biaryl Cross-Couplings between Various Aryl Electrophiles and Aryl Grignard Reagents
Wang, Lei,Wei, Yi-Ming,Zhao, Yan,Duan, Xin-Fang
, p. 5176 - 5186 (2019/05/10)
The combination of commonly used FeCl3/SIPr with Ti(OEt)4/PhOM enabled a highly general iron-based catalyst system, which could efficiently catalyze the biaryl coupling reaction between various electrophiles (I, Br, Cl, OTs, OCONMe2, OSO2NMe2) and common or functionalized aryl Grignard reagents with high functional group tolerance. Selective couplings of aryl iodides and bromides over the corresponding oxygen-based electrophiles have been achieved, and thus a terphenyl acid intermediate for anidulafungin was conveniently synthesized via an orthogonal coupling strategy.
Directed: Ortho C-H borylation catalyzed using Cp?Rh(iii)-NHC complexes
Thongpaen, Jompol,Schmid, Thibault E.,Toupet, Loic,Dorcet, Vincent,Mauduit, Marc,Baslé, Olivier
supporting information, p. 8202 - 8205 (2018/07/29)
Cp?Rh(NHC) complexes with bulky chiral bidentate NHC-carboxylate ligands were efficiently synthesized and fully characterized including solid-state structures. These unprecedented rhodium(iii) complexes demonstrated high selectivity in pyridine-directed ortho-C-H borylation of arenes under mild conditions.
Cobalt-Catalyzed Biaryl Couplings via C-F Bond Activation in the Absence of Phosphine or NHC Ligands
Wei, Juan,Liu, Kun-Ming,Duan, Xin-Fang
, p. 1291 - 1300 (2017/02/10)
A highly general and selective Co-catalyzed biaryl coupling through C-F cleavage under phosphine or NHC-free conditions was described. A broad range of aryl fluorides including unactivated fluorides as well as those with sensitive functionalities could couple with various Ti(OEt)4-mediated aryl Grignard reagents with high selectivity under the catalysis of CoCl2/DMPU. Importantly, selective C-F bond activation couplings between two types of fluorines (difluorinated aromatics and on two different coupling partners) and in the presence of C-Cl or C-Br bonds could also be achieved.
A Micellar Catalysis Strategy for Suzuki-Miyaura Cross-Couplings of 2-Pyridyl MIDA Boronates: No Copper, in Water, Very Mild Conditions
Isley, Nicholas A.,Wang, Ye,Gallou, Fabrice,Handa, Sachin,Aue, Donald H.,Lipshutz, Bruce H.
, p. 8331 - 8337 (2017/12/08)
Suzuki-Miyaura (SM) cross-couplings of 2-pyridyl MIDA boronates can be successfully carried out in the complete absence of copper by attenuation of the Lewis basicity associated with the pyridyl nitrogen using selected substituents (e.g., fluorine or chlorine) on the ring. This strategy imparts additional synthetic options compared with existing approaches based on the use of Lewis acids or N-oxides. Thus, access to highly valued 2-substituted pyridyl rings via an initial Suzuki-Miyaura coupling can be followed by dehalogenation, SNAr reactions, or a second SM coupling to arrive at 2,6-disubstituted pyridyl arrays, all run in a single pot, enabled by micellar catalysis in water. Accessing targets within drug-like space is demonstrated in a four-step, one-pot sequence. Computational data suggest that the major role being played by electron-withdrawing substituents in promoting these cross-couplings without the need for copper is to slow the rates of protodeboronation of intermediate 2-pyridylboronic acids.
α-Halo carbonyls enable: Meta selective primary, secondary and tertiary C-H alkylations by ruthenium catalysis
Paterson, Andrew J.,Heron, Callum J.,McMullin, Claire L.,Mahon, Mary F.,Press, Neil J.,Frost, Christopher G.
supporting information, p. 5993 - 6000 (2017/07/25)
A catalytic meta selective C-H alkylation of arenes is described using a wide range of α-halo carbonyls as coupling partners. Previously unreported primary alkylations with high meta selectivity have been enabled by this methodology whereas using straight chain alkyl halides affords ortho substituted products. Mechanistic analysis reveals an activation pathway whereby cyclometalation with a ruthenium(ii) complex activates the substrate molecule and is responsible for the meta selectivity observed. A distinct second activation of the coupling partner allows site selective reaction between both components.
Chemoselective Synthesis of Polysubstituted Pyridines from Heteroaryl Fluorosulfates
Zhang, Enxuan,Tang, Jiaze,Li, Suhua,Wu, Peng,Moses, John E.,Sharpless, K. Barry
supporting information, p. 5692 - 5697 (2016/04/20)
A selection of heteroaryl fluorosulfates were readily synthesized using commercial SO2F2 gas. These substrates are highly efficient coupling partners in the Suzuki reaction. Through judicious selection of Pd catalysts the fluorosulfate functionality is differentiated from bromide and chloride; the order of reactivity being: -Br> -OSO2F> -Cl. Exploiting this trend allowed the stepwise chemoselective synthesis of a number of polysubstituted pyridines, including the drug Etoricoxib. A selection of heteroaryl fluorosulfates were readily synthesized using commercial SO2F2 gas. These substrates are highly efficient coupling partners in the Suzuki reaction. Through judicious selection of Pd catalysts the fluorosulfate functionality is differentiated from bromide and chloride; the order of reactivity being: -Br> -OSO2F> -Cl. Exploiting this trend allowed the stepwise chemoselective synthesis of a number of polysubstituted pyridines, including the drug Etoricoxib.
Iron catalyzed oxidative assembly of N-heteroaryl and aryl metal reagents using oxygen as an oxidant
Liu, Kun Ming,Liao, Lian Yan,Duan, Xin Fang
supporting information, p. 1124 - 1127 (2015/01/09)
An equivalent amount of N-heteroaryl and aryl Grignard or lithium reagents, after mediation by an equivalent of titanate, was facilely coupled to furnish N-heteroaryl-aryl compounds under the catalysis of FeCl3/TMEDA at ambient temperature using oxygen as an oxidant. Most of the common N-heteroaryls were all good candidates, and thus provided a general, green and pratical protocol for the flexible construction of various N-heteroaryl-aryl structures. This journal is
Catalytic meta-selective C-H functionalization to construct quaternary carbon centres
Paterson, Andrew J.,St John-Campbell, Sahra,Mahon, Mary F.,Press, Neil J.,Frost, Christopher G.
supporting information, p. 12807 - 12810 (2015/08/06)
A catalytic meta-selective C-H functionalization of 2-phenylpyridines using a range of tertiary halides is described. The protocol is simple to perform and uses commercially available reagents to construct challenging quaternary carbon centres in a regioselective manner. Preliminary studies suggest the C-H functionalization proceeds through a radical process directed via a remote σ-activation.
Palladium-Catalyzed Cross-Coupling of Unactivated Aryl Sulfides with Arylzinc Reagents under Mild Conditions
Otsuka, Shinya,Fujino, Daishi,Murakami, Kei,Yorimitsu, Hideki,Osuka, Atsuhiro
supporting information, p. 13146 - 13149 (2016/02/19)
Cross-coupling of general aryl alkyl sulfides with arylzinc reagents proceeds smoothly, even at room temperature or below, with a palladium-N-heterocyclic carbene (NHC) catalyst. When combined with reactions that are unique to organosulfurs, that is, the SNAr sulfanylation or Pummerer reaction, the cross-coupling offers interesting transformations that are otherwise difficult to achieve. An alkylsulfanyl group is preferentially converted whilst leaving the tosyloxy and chloro intact, which expands the variety of orthogonal cross-coupling.
