描述了烷基,芳基和杂环亚胺与M盐之间的曼尼希型反应,用于通过使用纳米晶状氧化镁(NAP-MgO)合成α-硫烷基-β-氨基酸衍生物。这些产品以中等至高收率获得,具有适度的非对映选择性。X射线衍射技术已证实3-{[[(4-甲基苯基)磺酰基]氨基} -2-(甲基硫烷基)-3-(4-硝基苯基)丙酸乙酯(主要异构体)的构型是抗,并与基于1 H NMR光谱的赋值一致。这些α-硫烷基-β-氨基酸衍生物是具有强生物活性的药物的重要组成部分。
Concise Asymmetric Synthesis of Fully Substituted Isoxazoline-N-Oxide through Lewis Base Catalyzed Nitroalkene Activation
作者:Cheng Zhong、Lekh Nath S. Gautam、Jeffrey L. Petersen、Novruz G. Akhmedov、Xiaodong Shi
DOI:10.1002/chem.201001237
日期:2010.8.2
Transforming isoxazoline‐N‐oxides: A concise asymmetric synthesis of isoxazoline‐N‐oxides is reported through secondaryamine Lewis base catalyzednitroalkene activation and sequential intermolecular condensation with aldehydes and ylides. Application of camphor‐derived chiral sulfur ylides gave the enantiomeric‐enriched isoxazoline‐N‐oxides in excellent yields and stereoselectivity. Simple transformations
Amine nucleophilic addition to nitroalkene as a new practical approach for the synthesis of fully substituted isoxazoline-N-oxide
作者:Cheng Zhong、Lekh Nath S. Gautam、Dawei Wang、Novruz G. Akhmedov、Jeffrey L. Petersen、Xiaodong Shi
DOI:10.1016/j.tet.2011.01.085
日期:2011.6
secondary amine nucleophilic addition to the nitroalkene was used to generate the active nitronate intermediate, followed by the sequentialaddition to aldehyde and ylide, giving the fully substituted isoxazoline-N-oxide in one-pot fashion. Mechanistic studies revealed the equilibrium nature of the diene intermediates, which provide the foundation for the asymmetricsynthesis of this interesting heterocycles
Platinum‐Catalyzed α,β‐Desaturation of Cyclic Ketones through Direct Metal–Enolate Formation
作者:Ming Chen、Guangbin Dong
DOI:10.1002/anie.202013628
日期:2021.3.29
ketones to their conjugated α,β‐unsaturated counterparts is reported in this full article. A unique diene‐platinum complex was identified to be an efficient catalyst, which enables direct metal‐enolate formation. The reaction operates under mild conditions without using strong bases or acids. Good to excellent yields can be achieved for diverse and complex scaffolds. A wide range of functional groups, including
A novel and efficient method for the generation of o-quinone methide intermediates was developed from the readily available 2-tosylalkylphenols under the mildbasicconditions, and their reactions with sulfur ylides were investigated for the stereoselective synthesis of trans-2,3-dihydrobenzofurans.
Improved Convergent Synthesis of 5′-epi-Analogues of Muraymycin Nucleoside Antibiotics
作者:Christian Ducho、Anatol Spork、Stefan Koppermann
DOI:10.1055/s-0029-1217742
日期:2009.9
Nucleoside antibiotics represent a promising class of natural products for the development of novel antibacterial agents, with particular respect to structurally simplifiedanalogues maintaining biological activity. There are established truncated 5'-epi-derivatives of muraymycin nucleoside antibiotics with reported antibacterial properties, but the lengthy preparation of such compounds is a major