DIELS ALDER REACTIONS IN ROOM TEMPERATURE MOLTEN SALTS

室温熔盐中的狄尔斯桤木反应

• 批准号: 6107110
• 负责人: CARLOS W LEE
• 金额: $ 11.6万
• 依托单位: TENNESSEE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-06-01 至 2000-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6107110
• 关键词: Diels Alder reaction; aluminum; biological products; catalyst; chemical addition; chemical reaction; chemical synthesis; chlorine; gas chromatography mass spectrometry; intermolecular interaction; nuclear magnetic resonance spectroscopy; organic chemicals; salts; solvents; stereochemistry; thermodynamics; ultraviolet spectrometry

Ambient temperature chloroaluminate molten salts, AlCl/3:MCl, where Mcl is either 1-ethyl-3-methyl-1H-imidazolium chloride (EMIC) or N-1- butylpyridinium chloride (BPC), have never been used as solvents/catalysts for the synthetically important Diels-Alder reaction. This is unfortunate because one might expect to observe unusual and interesting [4pi + 2pi]- cycloaddition reactions in ionic liquids. The composition of molten salts can be easily varied from basic (EMIC or BPC in excess) to acidic (AlCl/3 in excess). This variable Lewis acidity of the molten salts is unique and should have a profound effect on Diels-Alder reactions. Furthermore, protons in ambient temperature molten salts function like Brphisted superacids with Hammett acidity functions, H/0, ranging from -12.6 (1.04: 1.0 mol ration AlCl/3-EMIC) to -18 (2: 1 mol ration AlCl/3-EMIC). This "doubly acidic" medium should significantly influence Diels-Alder reactions which is known to be affected by Lewis and Brphisted catalyst. These acid catalysts not only greatly accelerate the rate of reaction but also enhance diastereo-and regioselectivity. The proposed research involves a systematic investigation into the suitability of ambient temperature molten salts as solvents/catalysts for Diels-Alder reactions. Specific items to be studied include: (1) to highlight the potential of ambient temperature molten salts as useful solvents for intra- and intermolecular Diels-Alder and related reactions; (2) to investigate the influence of the solvent's Lewis and Brphisted acidity on Diels-Alder reactions; (3) to compare the Lewis versus Brphisted effect of the solvent on the rate and stereochemistry of Diels-Alder reactions; (4) to identify and characterize the reaction products and intermediates resulting from various intra- and intermolecular Diels-Alder reactions in the molten salt medium; and (5) to investigate the potential of molten salts as solvents/catalyst for synthesizing a variety of natural products and physiologically active molecules via Diels-Alder reactions. Results from the proposed study should provide the scientific community with a rather significant new area for material synthesis.

室温氯铝酸盐熔盐，AlCl/3：MCl，其中Mcl为 氯化1-乙基-3-甲基-1H-咪唑鎓（EMIC）或N-1- 氯化丁基吡啶鎓（BPC）从未用作溶剂/催化剂 合成重要的狄尔斯-阿尔德反应。这是不幸的 因为人们可能会期望观察到不寻常的和有趣的[4pi +2 pi]- 离子液体中的环加成反应。熔盐的组成 可以很容易地从碱性（EMIC或BPC过量）变化到酸性（AlCl/3 过量）。熔盐的这种可变的刘易斯酸性是独特的， 应该对狄尔斯-阿尔德反应有深远的影响。此外，委员会认为， 质子在室温熔盐中的作用类似于Brphisted 具有Hammett酸性功能的超强酸，H/0为-12.6（1.04： 1.0摩尔比AlCl/3-EMIC）至约18（2：1摩尔比AlCl/3-EMIC）。这 “双酸”介质对Diels-Alder方程有显著影响 已知该反应受刘易斯和Brphisted催化剂的影响。 这些酸催化剂不仅大大加快了反应速率， 也增强非对映体和区域选择性。拟议研究 包括对环境的适宜性进行系统的调查， 高温熔融盐作为溶剂/催化剂用于Diels-Alder反应。 具体研究项目包括：（1）突出 室温熔融盐作为用于内部和外部聚合的有用溶剂 分子间Diels-Alder反应及相关反应;（2）研究了分子间的Diels-Alder反应， 溶剂的刘易斯和Brphisted酸度对Diels-Alder的影响 反应;（3）比较溶剂的刘易斯效应与Brphisted效应 对Diels-Alder反应的速率和立体化学的影响;（4）鉴定 并表征反应产物和中间体， 各种内部和 熔融盐介质中的分子间Diels-Alder反应;和（5）至 研究熔融盐作为溶剂/催化剂的潜力， 合成多种天然产物和生理活性 分子通过Diels-Alder反应。拟议研究的结果 应该为科学界提供一个相当重要的新领域 用于材料合成。