82225-33-0Relevant academic research and scientific papers
Rh(iii)-Catalyzed three-component cascade annulation to produce theN-oxopropyl chain of isoquinolone derivatives
He, Yuan,Liao, Xian-Zhang,Dong, Lin,Chen, Fen-Er
, p. 561 - 567 (2021/02/06)
Developing powerful methods to introduce versatile functional groups at theN-substituents of isoquinolone scaffolds is still a great challenge. Herein, we report a novel three-component cascade annulation reaction to efficiently construct theN-oxopropyl chain of isoquinolone derivativesviarhodium(iii)-catalyzed C-H activation/cyclization/nucleophilic attack, with oxazoles used both as the directing group and potential functionalized reagents.
Silver-Free Au(I) Catalysis Enabled by Bifunctional Urea- and Squaramide-Phosphine Ligands via H-Bonding
Echavarren, Antonio M.,Franchino, Allegra,Martí, àlex,Nejrotti, Stefano
supporting information, p. 11989 - 11996 (2021/07/06)
A library of gold(I) chloride complexes with phosphine ligands incorporating pendant (thio)urea and squaramide H-bond donors was prepared with the aim of promoting chloride abstraction from Au(I) via H-bonding. In the absence of silver additives, complexes bearing squaramides and trifluoromethylated aromatic ureas displayed good catalytic activity in the cyclization of N-propargyl benzamides, as well as in a 1,6-enyne cycloisomerization, a tandem cyclization-indole addition reaction and the hydrohydrazination of phenylacetylene. Kinetic studies and DFT calculations indicate that the energetic span of the reaction is accounted by both the chloride abstraction step, facilitated by the bidentate H-bond donor via an associative mechanism, and the subsequent cyclization step.
Dual H-bond activation of NHC-Au(i)-Cl complexes with amide functionalized side-arms assisted by H-bond donor substrates or acid additives
Sepp?nen, Otto,Aikonen, Santeri,Muuronen, Mikko,Alamillo-Ferrer, Carla,Burés, Jordi,Helaja, Juho
supporting information, p. 14697 - 14700 (2020/12/02)
Novel approach with amide-tethered H-bond donor NHC ligands enabled Au(i)-catalysis via H-bonding. The plain NHC-Au(i)-Cl complex catalysed conversions of terminal N-propynamides to oxazolines, and enyne cycloisomerization with an acid additive, in DCM at
InCl3-catalyzed 5- exo-dig cyclization/1,6-conjugate addition of N -propargylamides with p -QMs to construct oxazole derivatives
Li, Ming,Li, Xue,Nan, Guang-Ming,Wen, Li-Rong,Yan, Ting-Xun,Yao, Tian-Yu
supporting information, p. 1780 - 1784 (2020/03/17)
An InCl3-catalyzed atom-economic intramolecular 5-exo-dig cyclization/1,6-conjugate addition/aromatization of N-propargylamides with p-QMs to produce oxazoles tethering diarylmethane has been successfully developed. InCl3 not only se
Synthesis of 2,2,2-Trifluoroethyl Oxazoles, Oxazolines and Furans via Alkyne Oxytrifluoromethylation
Dong, Jia-Jia,Zhang, Song-Lin
supporting information, p. 795 - 800 (2020/01/24)
This study reports an oxytrifluoromethylation method for construction of oxazoles and furans motif and the concurrent incorporation of a 2,2,2-trifluoroethyl group at the aromatic C5-position. High-valent copper(III) trifluoromethyl compounds are crucial
Gold(I) Complexes Stabilized by Nine- and Ten-Membered N-Heterocyclic Carbene Ligands
Cervantes-Reyes, Alejandro,Rominger, Frank,Rudolph, Matthias,Hashmi, A. Stephen K.
supporting information, p. 11745 - 11757 (2019/08/20)
Nine- and ten-membered N-heterocyclic carbene (NHC) ligands have been developed and for the first time their gold(I) complexes were synthesized. The protonated NHC pro-ligands 2 a–h were prepared by the reaction of readily available N,N′-diarylformamidines with bis-electrophilic building blocks, followed by anion exchange. In situ deprotonation of the tetrafluoroborates 2 a–h with tBuOK in the presence of AuCl(SMe2) provided fast access to NHC-gold(I) complexes 3–10. These new NHC-gold(I) complexes show very good catalytic activity in a cycloisomerization reaction (0.1 mol % catalyst loading, up to 100 % conversion) and their solid-state structures reveal high steric hindrance around the metal atom (%Vbur up to 53.0) which is caused by their expanded-ring architecture.
Zn(OTf)2-catalyzed, microwave-promoted synthesis of 2-substituted 5-methyloxazoles from propargylic amides
Safrygin, Alexander,Dar'in, Dmitry,Lukin, Alexei,Bakholdina, Anna,Sapegin, Alexander,Krasavin, Mikhail
supporting information, p. 777 - 779 (2019/02/13)
The versatile conversion of propargylic amides to the respective 2-substituted 5-methyloxazoles was efficiently catalyzed by Zn(OTf)2 (5 mol%) under microwave irradiation in toluene. The method was applicable to a wide range of aliphatic, aroma
Assessing the influence of phosphine substituents on the catalytic properties of self-stabilised digold(i) complexes with supporting ferrocene phosphinonitrile ligands
Barta, Ondrej,Cisarova, Ivana,Schulz, Jiri,Stepnicka, Petr
supporting information, p. 11258 - 11262 (2019/07/31)
Gold(i) phosphine complexes are often used in catalysis, but the role of their auxiliary ligands still remains poorly understood. Thus, building on our previous research, we prepared a series of Au(i) complexes [Au2(μ-R2PfcCN)2][SbF6]2 (fc = ferrocene-1,1
Palladium-Catalyzed Cascade Difluoroalkylation/Cyclization of N-Propargylamides: Synthesis of Oxazoles and Oxazolines
Ma, Jun-Wei,Wang, Qiang,Wang, Xin-Gang,Liang, Yong-Min
, p. 13296 - 13307 (2018/11/02)
A palladium-catalyzed process to construct oxazoles and oxazolines with broad functional-group tolerance has been developed, and the method introduces difluoromethyl groups into heterocycles in a one-pot fashion. This system uses a carbonyl oxygen as the acceptor for the addition of a vinylpalladium intermediate to achieve the cyclization. Oxazoline derivatives are generated as the Z-isomer with high stereoselectivity. Additionally, we validated the tentative mechanism of this reaction.
Base-Promoted Cycloisomerization for the Synthesis of Oxazoles and Imidazoles
Zhang, Lidan,Xiao, Ke,Qiao, Yan,Li, Xin,Song, Chuanjun,Chang, Junbiao
supporting information, p. 6913 - 6918 (2018/12/05)
Treatment of propargylamides or propargylamidines with cesium carbonate in DMSO results in the formation of the corresponding oxazoles or imidazoles in good yields. A large variety of substrates with various functional groups are tolerated. DFT study on a model substrate reveals that the reactions proceed via a sequence involving allene formation, intramolecular cyclization, and double-bond isomerization.
