871022-77-4Relevant academic research and scientific papers
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.
Ir(I)-Catalyzed Synthesis of (E)-4-Benzylidenylacridines and (E)-2-Styrylquinoline-3-carboxamide through Sequential Suzuki–Miyaura Coupling, Dehydrogenative Friedl?nder Reaction, and sp3-C–H Activation
Prameela, Soda,Nawaz Khan, Fazlur-Rahman
, p. 5394 - 5410 (2020/08/27)
An efficient one-pot strategy evolved in the synthesis of (E)-4-benzylidenylacridin-1(2H)-ones, (4 or 9) (E)-2-styryl quinoline-3-carboxamides (5 or 10) by sequential Suzuki–Miyaura coupling-dehydrogenative Friedl?nder-sp3 C–H activation. The 2-amino-5-chloro benzhydrol 1, aromatic alcohol 2 or 6 ketones 3 or 3', and phenylboronic acid 7 underwent a smooth reaction in a basic deep eutectic solvent consisting of K2CO3 and ethylene glycol (DES-1,1:1). DES-1 could enable the Pd-catalyzed Suzuki coupling reaction of 6, as well as the rapid oxidation of primary, secondary, and Suzuki coupled primary alcohols (2, 1, and 8) in the presence of an iridium catalyst and 1,10-phenanthroline. The acidic DES-2 (dimethyl urea/tartaric acid, 7:3) assists the Friedl?nder annulation and subsequent sp3-C–H functionalization resulting in (E)-4-benzylidenylacridin-1(2H)-ones (4 or 9) and (E)-2-styryl quinoline-3-carboxamides (5 or 10).
Amine capture strategy for peptide bond formation by means of quinolinium thioester salts
Leleu, Stephane,Penhoat, Mael,Bouet, Alexis,Dupas, Georges,Papamicael, Cyril,Marsais, Francis,Levacher, Vincent
, p. 15668 - 15669 (2007/10/03)
A new and unprecedented exploitation of quinolinium thioester salts 2 in peptide bond formation is reported. These synthetic tools were assessed during the preparation of a number of dipeptides 3a-f obtained in good yields with complete stereochemical integrity. A sequential mechanism related to a prior amine capture strategy is well-established. Additionally, a tripeptide 3g was prepared according to a "safety-catch" approach, thus demonstrating the important potential of these new synthetic tools in the design of new safety-catch linkers exploitable in Solid-Phase Peptide Synthesis (SPPS). Copyright
