405873-09-8Relevant articles and documents
Alkyne Hydroheteroarylation: Enantioselective Coupling of Indoles and Alkynes via Rh-Hydride Catalysis
Cruz, Faben A.,Zhu, Yamin,Tercenio, Quentin D.,Shen, Zengming,Dong, Vy M.
, p. 10641 - 10644 (2017)
We report an enantioselective coupling between alkynes and indoles. A Rh-hydride catalyst isomerizes alkynes to generate a metal-allyl species that can be trapped with both aromatic and heteroaromatic nucleophiles.
Hydrogen-bond-mediated supramolecular iminium ion catalysis
Wang, Yao,Yu, Tian-Yang,Zhang, Hong-Bo,Luo, Yong-Chun,Xu, Peng-Fei
, p. 12339 - 12342 (2012)
Mod squad: Multiple small molecules appear to spontaneously self-assemble to form supramolecular amine catalysts that have high reactivity, good efficiency, and enhanced turnover numbers. These modular organocatalysts should be applicable to many iminium as well as hydrogen-bond catalytic reactions and provide new insights into asymmetric catalysis. Copyright
Re-Engineering Organocatalysts for Asymmetric Friedel-Crafts Alkylation of Indoles through Computational Studies
Gerosa, Gabriela G.,Marcarino, Maribel O.,Spanevello, Rolando A.,Suárez, Alejandra G.,Sarotti, Ariel M.
, p. 9969 - 9978 (2020/09/03)
The discovery of efficient organocatalysts is generally carried out by thorough experimental screening of different candidates. We recently reported an efficient organocatalyst for iminium-ion-based asymmetric Diels-Alder reactions following a rational design approach. This result encouraged us to test this optimal catalyst in the mechanistically related Friedel-Crafts alkylation of indoles, but to our surprise, almost null enantioselectivity was observed. The results did not significantly improve with structurally related catalysts, and a totally unexpected facial selectivity inversion was also noticed. Using DFT calculations by modeling the competing transition structures with ONIOM, we could unravel the origins of those findings, further employed to predict the most efficient catalyst for this new transformation. The computational results were validated experimentally (up to 92:8 er), providing another successful example of a general strategy to accelerate catalyst development which still remains underexplored.
Polystyrene or Magnetic Nanoparticles as Support in Enantioselective Organocatalysis? A Case Study in Friedel-Crafts Chemistry
Ranjbar, Sara,Riente, Paola,Rodríguez-Escrich, Carles,Yadav, Jagjit,Ramineni, Kishore,Pericàs, Miquel A.
supporting information, p. 1602 - 1605 (2016/05/02)
Heterogenized versions of the second-generation MacMillan imidazolidin-4-one are described for the first time. This versatile organocatalyst has been supported on 1% DVB Merrifield resin and Fe3O4 magnetic nanoparticles through a copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction. The resulting catalytic materials have been successfully applied to the asymmetric Friedel-Crafts alkylation of indoles with α,β-unsaturated aldehydes. While both catalytic systems can be easily recovered and admit repeated recycling, the polystyrene-based catalyst shows higher stability and provides better stereoselectivities.
Highly stereoselective imidazolethiones mediated Friedel-Crafts alkylation of indole derivatives
Liang, Xianrui,Li, Shuangmin,Su, Weike
supporting information; experimental part, p. 289 - 291 (2012/01/31)
The asymmetric Friedel-Crafts alkylation of indoles with α,β-unsaturated aldehydes was promoted by the novel imidazolethiones to afford the corresponding adducts in moderate to excellent yields and high enantioselectivities under mild reaction conditions.
Enantioselective friedel-crafts alkylation of indoles with aromatic αβ-unsaturated aldehydes catalyzed by diphenylprolinol silyl Ether
Wang, Zhi-Jing,Yang, Jian-Guo,Jin, Jun,Lv, Xin,Bao, Weiliang
scheme or table, p. 3994 - 4000 (2010/03/24)
A catalytic enantioselective Friedel-Crafts alkylation of indoles with aromatic α,β-unsaturated aldehydes has been developed. The process is promoted by (S)-diphenylprolinol trimethyl silyl ether to afford, after sodium borohydride mediated reduction, 3in
Controllable Enantioselective Friedel-Crafts Reaction between Indoles and Alkylidene Malonates Catalyzed by Pseudo-C3-Symmetric Trisoxazoline Copper(II) Complexes
Zhou, Jian,Ye, Meng-Chun,Huang, Zheng-Zheng,Tang, Yong
, p. 1309 - 1320 (2007/10/03)
Pseudo-C3-symmetric trisoxazoline copper(II) complexes prove to be excellent catalysts in the Friedel-Crafts alkylation of indoles with alkylidene malonates. The absolute stereochemistry of this reaction is shown to be dependent on the solvent.
Enantioselective organocatalytic indole alkylations. Design of a new and highly effective chiral amine for iminium catalysis
Austin, Joel F.,MacMillan, David W. C.
, p. 1172 - 1173 (2007/10/03)
The indole framework has become widely identified as a "privileged" structure with representation in over 3000 natural isolates and 40 medicinal agents of diverse therapeutic action. A new strategy for asymmetric access to this important pharmacaphore has
Sidearm effect: Improvement of the enantiomeric excess in the asymmetric Michael addition of indoles to alkylidene malonates
Zhou, Jian,Tang, Yong
, p. 9030 - 9031 (2007/10/03)
A pseudo-C3-trisoxazoline was designed and synthesized. The improvement of the traditional bisoxazoline into a novel trisoxazoline by a sidearm approach resulted in highly catalytic enantioselective Michael addition of indoles to alkylidene mal