6637-33-8Relevant articles and documents
Selective synthesis of 2-indolyl-3-oxoindolines or 2-(2-aminophenyl)quinolines through Cu(II)- or Bi(III)-catalyzed tunable dimerizations of 2-alkynylanilines
Jia, Ruixue,Li, Bin,Zhang, Xinying,Fan, Xuesen
supporting information, p. 6810 - 6815 (2020/09/15)
A novel and selective synthesis of 2-indolyl-3-oxoindolines or 2-(2-aminophenyl)quinolines through tunable dimerizations of 2-alkynylanilines is presented. Mechanistically, the formation of 2-indolyl-3-oxoindolines involves a Cu(OAc)2/O2-promoted intramolecular cyclization of 2-alkynylaniline to give the required indole and 3H-indol-3-one intermediates followed by the indolylation of 3H-indol-3-one. On the other hand, the formation of 2-(2-aminophenyl)quinolines is believed to go through a Bi(OTf)3/MesCO2H-catalyzed intermolecular N-nucleophilic addition between two 2-alkynylaniline molecules to give an enamine intermediate followed by its intramolecular C-nucleophilic addition/annulation. Notable features of these new methods include easily obtainable substrates, economical catalysts and oxidant, controllable selectivity, and high versatility toward diverse products.
Unveiling reactive metal sites in a Pd pincer MOF: Insights into Lewis acid and pore selective catalysis
Reiner, Benjamin R.,Kassie, Abebu A.,Wade, Casey R.
supporting information, p. 9588 - 9595 (2019/07/09)
A porous Zr metal-organic framework, 1-PdBF4 [Zr6O4(OH)4(OAc)2.4{(PNNNP)Pd(MeCN)}2.4(BF4)2.4; PNNNP = 2,6-(HNPAr2)2C5H3N; Ar = p-C6H4CO2-], has been synthesized via postsynthetic oxidative I-/BF4- ligand exchange using NOBF4. 1-PdBF4 enjoys markedly superior catalytic activity and recyclability to its trifluoracetate-exchanged analogue, 1-PdTFA, for the intramolecular cyclization of o-alkynyl anilines and the carbonyl-ene cyclization of citronellal. Moreover, 1-PdBF4 demonstrates a rare example of pore selective catalysis for the cyclization of 2-ethynyl aniline.
Revisiting the Gold-Catalyzed Dimerization of 2-Ethynylanilines: A Room-Temperature and Silver-Free Protocol for the Synthesis of Multifunctional Quinolines
Praveen, Chandrasekar,Perumal
, p. 855 - 864 (2016/03/15)
A room temperature and silver-free protocol for the formation of quinolines from 2-ethynylanilines through a dimerization event was achieved using a dinuclear gold catalyst, Au2(BIPHEP)(NTf2)2. The reaction is inherently modular, allowing for the incorporation of peripheral substituents at any site of the quinoline product. The reaction is readily applied to other heterocyles also as exemplified by the preparation of naphthyridines. Competition reactions to determine the reactivity of dissimilar alkynes demonstrated that the product ratio of dimerization vs intermolecular addition is rather dependent on the electronic nature of aryl substituent on the alkynes. However, control experiments with substrates possessing internal alkynes resulted in cycloisomerization instead of expected dimerization, which is indicative of possible steric influence of the alkyne terminus in the reaction outcome.
