Design, synthesis, and application of chiral electron-poor guanidines as hydrogen-bonding catalysts for the Michael reaction
摘要:
The first chiral electron-poor guanidine organocatalysts were synthesized. The presence of a tunable electron-withdrawing group on the guanidine moiety allows for the modulation of the catalysts' activity. The application of this new class of organocatalysts to the Michael reaction is demonstrated. (C) 2010 Elsevier Ltd. All rights reserved.
A Mild Highly Efficient and Green Protocol for Preparation of N-alk-2′-Enoyl Cyclic Imides Using Basic Ionic Liquid [bmIm]OH as Base and Reaction Medium
作者:Yongjiang Wang、Jianwei Mao、Wen Pei
DOI:10.3184/030823408x356305
日期:2008.10
An efficient and green protocol for the preparation of N-alk-2′-enoyl cyclic imides at room temperature was developed using a basic ionicliquid, 1-methyl-3-butylimidazolium hydroxide, [bmIm]OH, as a base and a reactionmedium.
Although aerobic oxidative acylation of amides with alcohols would be a good complement to classical synthetic methods for imides (e.g., acylation of amides with activated forms of carboxylic acids), to date, there have been no reports on oxidative acylation to produce imides. In this study, we successfully developed, for the first time, an efficient method for the synthesis of imides through aerobic oxidative acylation
尽管酰胺与醇的有氧氧化酰化是对酰亚胺的经典合成方法(例如,用活化形式的羧酸酰化酰胺)的良好补充,但迄今为止,还没有关于氧化酰化生产酰亚胺的报道。在本研究中,我们首次成功开发了一种采用 CuCl/TMEDA/nor-AZADO 催化剂体系(TMEDA = 四甲基乙二胺;nor-AZADO = 9-氮杂金刚烷N-氧基)。所提出的酰化通过以下顺序反应进行:醇有氧氧化成醛,酰胺与醛亲核加成形成半酰胺中间体,以及半酰胺中间体有氧氧化得到相应的酰亚胺。该催化系统利用O 2作为终端氧化剂并产生水作为唯一的副产物。实现这种有效酰化系统的一个重要点是TMEDA配体的利用,据我们所知,该配体尚未在之前报道的Cu/配体/ N-氧基系统中使用。基于实验证据,我们认为 TMEDA 的可能作用包括促进半酰胺氧化和从 Cu I物种再生活性 Cu II -OH 物种。这里促进半酰胺氧化尤其重要。利用所提出的系统,可以从醇
Biomimetic Photocycloaddition of 3-Hydroxyflavones: Synthesis and Evaluation of Rocaglate Derivatives as Inhibitors of Eukaryotic Translation
作者:Stéphane P. Roche、Regina Cencic、Jerry Pelletier、John A. Porco
DOI:10.1002/anie.201003212
日期:2010.9.3
Shedding light on translation: A light‐driven, biomimetic [3+2] cycloaddition has been achieved with the synthesis of a series of rocaglate derivatives. Mechanistic data suggest the possibility for donor–acceptor interactions and the involvement of triplet biradicaloids in the photoexcited state. Several new rocaglate derivatives approach the potency of the anticancer agent silvestrol.
Highly Efficient Asymmetric Michael Addition of Diaryl Phosphine Oxides to α,β-Unsaturated N-Acylated Oxazolidin-2-ones
作者:Depeng Zhao、Linqing Wang、Dongxu Yang、Yixin Zhang、Rui Wang
DOI:10.1002/asia.201200025
日期:2012.5
A highlyefficientasymmetricMichael reaction of diarylphosphineoxides with α,β‐unsaturated N‐acylated oxazolidinones has been developed. Excellent enantioselectivities (up to >99 % ee) and chemical yields (up to 99 %) were achieved with a broad substrate scope of the oxazolidinones. The bidentate property of oxazolidinones was found to be critical for high enantioselectivities.
Design, synthesis, and application of chiral electron-poor guanidines as hydrogen-bonding catalysts for the Michael reaction
作者:Karen Thai、Michel Gravel
DOI:10.1016/j.tetasy.2010.04.033
日期:2010.4
The first chiral electron-poor guanidine organocatalysts were synthesized. The presence of a tunable electron-withdrawing group on the guanidine moiety allows for the modulation of the catalysts' activity. The application of this new class of organocatalysts to the Michael reaction is demonstrated. (C) 2010 Elsevier Ltd. All rights reserved.