1449770-04-0Relevant articles and documents
Phosphine-catalyzed intramolecular Rauhut-Currier reaction: Enantioselective synthesis of hydro-2: H -indole derivatives
Jin, Hongxing,Zhang, Qinglong,Li, Erqing,Jia, Penghao,Li, Ning,Huang, You
, p. 7097 - 7101 (2017)
A highly enantioselective intramolecular Rauhut-Currier reaction catalyzed by a multifunctional chiral aminophosphine catalyst was reported. A series of hydro-2H-indole derivatives that bear an all-carbon quaternary center were obtained in high yields (up to 94%), and excellent diastereo- and enantioselectivities (up to >20:1 dr and >99% ee). And this reaction could be performed on a gram scale using 2 mol% catalyst loading.
Diastereoselective Desymmetrization of p-Quinamines through Regioselective Ring Opening of Epoxides and Aziridines
Jadhav, Sandip B.,Chegondi, Rambabu
, p. 10115 - 10119 (2019/12/24)
A highly diastereoselective desymmetrization of p-quinamines via regioselective ring opening of epoxides and aziridines under mild conditions has been developed. A chairlike six-membered transition state with minimized 1,3-diaxial interactions explains the relative stereoselectivity of the cyclization reaction. This transition-metal free [3 + 3] annulation reaction provides rapid access to fused bicyclic morpholines and piperazines with a tetrasubstituted carbon center in high yields. In addition, it also allows the synthesis of enantioenriched products by using easily accessible chiral nonracemic epoxides and aziridines.
(3 + 2)-Annulation of p-Quinamine and Aryne: A Strategy to Construct the Multisubstituted Hydrocarbazoles
Xu, Dengyu,Zhao, Yulong,Song, Dengpeng,Zhong, Zhuliang,Feng, Shangbiao,Xie, Xingang,Wang, Xiaolei,She, Xuegong
, p. 3600 - 3603 (2017/07/15)
A strategy for the synthesis of multisubstituted hydrocarbazoles has been developed through (3 + 2)-annulation of p-quinamines and arynes. In this way, new analogs of hydrocarbazoles with quaternary carbon center can be synthesized in satisfactory yield under mild conditions. Furthermore, this (3 + 2)-annulation can be easily scaled-up, and the products can be modified through simple transformation.
[3 + 2]-Annulation of Prop-2-ynylsulfonium Salts: Access to Hydroindol-5-ones Containing a Methylthio Group
Jia, Penghao,Zhang, Qinglong,Jin, Hongxing,Huang, You
supporting information, p. 412 - 415 (2017/04/21)
An unprecedented [3 + 2]-annulation of prop-2-ynylsulfonium salts and p-quinamines was developed, affording a series of hydroindol-5-ones with a methylthio group in moderate to good yields under mild conditions. In this reaction, the prop-2-ynylsulfonium
Enantioselective Desymmetrization of para-Quinamines through an Aminocatalyzed Aza-Michael/Cyclization Cascade Reaction
Pantaine, Lo?c,Coeffard, Vincent,Moreau, Xavier,Greck, Christine
supporting information, p. 3674 - 3677 (2015/08/18)
An unprecedented organocatalytic asymmetric desymmetrization of para-quinamines leading to functionalized hydroindoles, a common motif in many alkaloids, has been reported. The ability of diarylprolinol silyl ethers to promote iminium and enamine activation of α,β-unsaturated aldehydes in one catalytic cycle is the centerpiece of the strategy involving a challenging aza-Michael/intramolecular cyclization cascade reaction. A range of prochiral para-quinamines and α,β-unsaturated aldehydes were investigated to afford 16 examples of hydroindoles possessing four contiguous stereocenters including one quaternary carbon. The hydroindole structures include multiple orthogonal functionalities, which underwent various transformations.
Ligand and substrate effects during Pd-catalyzed cyclizations of alkyne-tethered cyclohexadienones
Tello-Aburto, Rodolfo,Kalstabakken, Kyle A.,Harned, Andrew M.
supporting information, p. 5596 - 5604 (2013/09/12)
The effects of ligand and substrate choice on the Pd-catalyzed cyclization of alkyne-tethered cyclohexadienones were examined. In the presence of a chiral ligand, the enantioselectivity of the desymmetrization is remarkably sensitive to structural changes in both the ligand and the substrate. Additionally, the regioselectivity of the reaction (5- vs. 6-membered ring formation) is dependent on the proximity of heteroatoms to the alkyne.
