22514-82-5Relevant articles and documents
Oxidative Dimerization of Quinolinic Nitroxides in the Presence of Trichloro- and Trifluoro- Acetic Acid. Crystal Structures of 6,6'-bis-(1-oxide-1,2,6,8a-tetrahydroquinoline)ylidene and of 2,3-Diphenylquinoline
Carloni, Patricia,Daminani, Elisabetta,Greci, Lucedio,Stipa, Pierluigi,Rizzoli, Corrado,et al.
, p. 5099 - 5108 (1993)
Quinolinic nitroxides 1a-c react with trichloro- (TCA) and trifluoro- (TFA) acetic acid to give dimers 3a-c and 4a-c as the main products.Products 3a-c are explained as arising via the intermediate formation of the radical cation 5, which forms the final
Unexpected Annulation between 2-Aminobenzyl Alcohols and Benzaldehydes in the Presence of DMSO: Regioselective Synthesis of Substituted Quinolines
Yang, Tonglin,Nie, Zhi-Wen,Su, Miao-Dong,Li, Hui,Luo, Wei-Ping,Liu, Qiang,Guo, Can-Cheng
, p. 15228 - 15241 (2021/10/25)
An unexpected annulation among 2-aminobenzyl alcohols, benzaldehydes, and DMSO to quinolines has been disclosed. For the reported annulation between 2-aminobenzyl alcohols and benzaldehydes, the change of the solvent from toluene to DMSO led to the change of the product from the diheteroatomic cyclic benzoxazines to monoheteroatomic cyclic quinolines. This annulation can be used to synthesize regioselectively different substituted quinolines by the choice of different 2-amino alcohols, aldehydes, and sulfoxides as substrates. Interestingly, introducing substituent groups to the α-position of sulfoxides resulted in the interchange of the positions between benzaldehydes and sulfoxides in the product quinolines. On the basis of the control experiments and literatures, a plausible mechanism for this annulation was proposed.
NiH-Catalyzed Hydroamination/Cyclization Cascade: Rapid Access to Quinolines
Chen, Qian,Gao, Yang,Hu, Xiao-Qiang,Huo, Yanping,Li, Xianwei,Yang, Simin
, p. 7772 - 7779 (2021/06/30)
Despite the significant success of metal-H-catalyzed hydroamination methodologies, considerable limitations still exist in the selective hydroamination of alkynes, especially for terminal alkynes. Herein, we develop a highly efficient NiH catalytic system that activates readily available alkynes for a cascade hydroamination/cyclization reaction with anthranils. This mild, operationally simple protocol is amenable to a wide array of alkynes including terminal and internal, aryl and alkyl, electron-deficient and electron-rich ones, delivering structurally diverse quinolines in useful to excellent yields (>80 examples, up to 93% yield). The utility of this procedure is exhibited in the late-stage functionalization of several natural products and in the concise synthesis of an antitumor molecule graveolinine and a triplex DNA intercalator. Preliminary mechanistic experiments suggest an alkenylnickel-mediated alkyne hydroamination and an intramolecular cyclization/aromatization of putative enamine intermediates.
