62059-59-0Relevant articles and documents
Studies on asymmetric total synthesis of (?)-β-hydrastineviaa chiral epoxide ring-opening cascade cyclization strategy
Cheng, Maosheng,Li, Jihui,Liu, Yongxiang,Meng, Jiaxin,Qin, Qiaohua,Song, Xinjing,Wu, Tianxiao,Zhao, Dongmei,Zheng, Yang
, p. 18953 - 18958 (2020/06/08)
Herein, facile and enantioselective approaches to synthesize the core phthalide tetrahydroisoquinoline scaffold of (?)-β-hydrastineviaboth a CF3COOH-catalyzed (86% ee) and KHMDS-catalyzed (78% ee) epoxide ring-opening/transesterification cascade cyclization from chiral epoxide under very mild conditions are described. The key elements include a highly enantioselective epoxidation using the Shi ketone catalyst and an intramolecular CF3COOH-catalyzed cascade cyclization in one pot, and a late-stage C-3′ epimerization under MeOK/MeOH conditions as the key steps to achieve the first total synthesis of (?)-β-hydrastine (up to 81% ee).
An Acid-Catalyzed Epoxide Ring-Opening/Transesterification Cascade Cyclization to Diastereoselective Syntheses of (±)-β-Noscapine and (±)-β-Hydrastine
Li, Jihui,Liu, Yongxiang,Song, Xinjing,Wu, Tianxiao,Meng, Jiaxin,Zheng, Yang,Qin, Qiaohua,Zhao, Dongmei,Cheng, Maosheng
, p. 7149 - 7153 (2019/09/30)
An acid-catalyzed stereoselective epoxide ring-opening/intramolecular transesterification cascade cyclization reaction and N-Boc deprotection was found to be a successful strategy to construct the phthalide tetrahydroisoquinoline skeleton in one pot. Based on this strategy, the unified and highly diastereoselective routes for the total syntheses of (±)-β-Noscapine and (±)-β-Hydrastine were exploited.
A general catalytic route to isoindolinones and tetrahydroisoquinolines: Application in the synthesis of (±)-crispine A
Dhanasekaran, Sivasankaran,Bisai, Vishnumaya,Unhale, Rajshekhar A.,Suneja, Arun,Singh, Vinod K.
supporting information, p. 6068 - 6071 (2015/01/09)
An unprecedented highly efficient Lewis acid catalyzed one-pot cascade has been demonstrated as a general catalytic system for the synthesis of diversely substituted isoindolinones and tetrahydroisoquinolines. The cascade effects one C-C and two C-N bond-
Naphthopyranone synthesis via the tandem Michael-Dieckmann reaction of ortho-toluates with 5,6-dihydropyran-2-ones
Tan, Nichole P.H.,Donner, Christopher D.
, p. 4160 - 4162 (2008/09/20)
The tandem Michael-Dieckmann reaction between a series of ortho-toluates and the α,β-unsaturated lactone 25 is described. The tandem reaction delivers substituted naphthopyranones in moderate (20-49%) yields, whilst limitations in the tolerance of this reaction for different substituents on the ortho-toluate are identified. Crown Copyright
Studies on isocyanides: synthesis of tetrazolyl-isoindolinones via tandem Ugi four-component condensation/intramolecular amidation
Marcos, Carlos F.,Marcaccini, Stefano,Menchi, Gloria,Pepino, Roberto,Torroba, Tomás
, p. 149 - 152 (2008/04/13)
The Ugi four-component condensation between methyl o-formylbenzoates 1, anilines 2a-c, isocyanides 3, and trimethylsilyl azide (4) afforded the expected Ugi adducts 5a-d, which were cyclized to the title compounds 6a-d upon treatment with sodium ethoxide
Arene-Metal Complex in Organic Synthesis: Directed Regioselective Lithiation of (?-Substituted benzene)chromium Tricarbonyl Complexes
Uemura, Motokazu,Nishikawa, Naomi,Take, Kazuhiko,Ohnishi, Masato,Hirotsu, Ken,et al.
, p. 2349 - 2356 (2007/10/02)
(3-Methoxybenzyl alcohol)chromium tricarbonyl complex (8) and (2-substituted 7-methoxy-1-tetralol)chromium complexes 14-17 are selectively lithiated at the 4-position and 6-position, respectively, by treatment with n-BuLi/TMEDA.The regioselectivity of this lithiation is improved with increasing bulk of the butyllithium reagent employed.Since the direct lithiation of the corresponding chromium-free arenes normally proceeds at the 2- and 8-positions, complementarily substituted arenes can be prepared by using chromium tricarbonyl complexes.The different lithiation is explained by the relative configuration of the chromium tricarbonyl group in the (?-arene)Cr(CO)3 complexes and the electrostatic factor.This rationalization is supported, at least in part, by X-ray crystallography of the complex 16.On the other hand, the chromium complexes of arenes without a free hydroxyl group, such as benzyl methyl ether or ethylene acetals of benzaldehydes, are lithiated at the 2-position preferentially.
