Formation of substituted 2-iminooxazolidines via intermolecular 1,2-addition/intramolecular N-vinylation using 3-substituted-2-bromo-2-propen-1-ols as substrates
摘要:
The Cu2O-catalyzed reaction between equimolar amounts of easily available 3-substituted-2-bromo-2-propen-1-ols and dicyclohexyl carbodiimide in DMSO at 100 degrees C using K3PO4 as the base and in the absence of any additive exclusively delivers substituted 2-iminooxazolidines with yields up to 80%. The highly selective transformation is assumed to start with an intermolecular 1,2-addition, which is followed by an intramolecular N-vinylation. The products can also be obtained in the absence of Cu2O, albeit in lower yields. (C) 2018 Elsevier Ltd. All rights reserved.
Highly Enantioselective Catalytic Synthesis of Neurite Growth-Promoting Secoyohimbanes
作者:Andrey P. Antonchick、Sara López-Tosco、Juan Parga、Sonja Sievers、Markus Schürmann、Hans Preut、Susanne Höing、Hans R. Schöler、Jared Sterneckert、Daniel Rauh、Herbert Waldmann
DOI:10.1016/j.chembiol.2013.03.011
日期:2013.4
rhynchophylline, a highly enantioselective and efficient organocatalyzed synthesis method was developed that gives access to the tetracyclic secoyohimbane scaffold, embodying a quaternary and three tertiarystereogeniccenters in a one-pot multistep reaction sequence. Investigation of a collection of the secoyohimbanes in primary rat hippocampal neurons and embryonal stem cell-derived motor neurons led
Enantioselective Organocatalytic Synthesis of a Secoyohimbane-Inspired Compound Collection with Neuritogenic Activity
作者:Tim Förster、Sara López-Tosco、Slava Ziegler、Andrey P. Antonchick、Herbert Waldmann
DOI:10.1002/cbic.201700015
日期:2017.6.19
the neuroprotective alkaloid rhynchophylline was synthesized employing a highly efficient enantioselective and organocatalyzed cascade process. Evaluation of the developed compound collection showed a family of neurotrophic compounds.
Organocatalytic Asymmetric Formal [3+3] Cycloaddition Reactions of α,β-Unsaturated Aldehydes with Nazarov Reagents
作者:Ming-Kui Zhu、Qiang Wei、Liu-Zhu Gong
DOI:10.1002/adsc.200800174
日期:2008.6.9
An organocatalyticasymmetricformal [3+3] cycloaddition reaction of α,β-unsaturated aldehydes with Nazarov reagents promoted by prolinol derivatives afforded, after oxidation, 3,4-dihydropyranones in good yields with high enantioselectivities of up to 97% ee.
hexahydropyrrolo-isoquinolines through the 1,3-dipolarcycloaddition of cinnamaldehydes with azomethine ylides generated from cinnamaldehydes and tetrahydroisoquinolines. The carbonyl CO groups of cinnamaldehydes serve as the precursor for the generation of azomethine ylides and the CC double bonds of cinnamaldehyde act as the dipolarophiles in the cycloaddition. The key features are easily available substrates
描述了一种通过肉桂醛与由肉桂醛和四氢异喹啉生成的偶氮甲碱叶立德进行 1,3-偶极环加成反应合成六氢吡咯并异喹啉的新方法。肉桂醛的羰基 C O 基团作为偶氮甲碱叶立德和 C肉桂醛的 C 双键在环加成中充当亲偶极试剂。主要特点是容易获得底物、良好的官能团耐受性和温和的反应条件。通过X射线单晶结构分析确定了产物的相关构型,并提出了可能的机理。进行了克级实验和一些化学转化以显示该方法的综合效用。最后,提出了一种似是而非的机制来阐明具有不同配置的产品的形成。
Formation of substituted 2-iminooxazolidines via intermolecular 1,2-addition/intramolecular N-vinylation using 3-substituted-2-bromo-2-propen-1-ols as substrates
The Cu2O-catalyzed reaction between equimolar amounts of easily available 3-substituted-2-bromo-2-propen-1-ols and dicyclohexyl carbodiimide in DMSO at 100 degrees C using K3PO4 as the base and in the absence of any additive exclusively delivers substituted 2-iminooxazolidines with yields up to 80%. The highly selective transformation is assumed to start with an intermolecular 1,2-addition, which is followed by an intramolecular N-vinylation. The products can also be obtained in the absence of Cu2O, albeit in lower yields. (C) 2018 Elsevier Ltd. All rights reserved.