DIELS ALDER REACTIONS IN ROOM TEMPERATURE MOLTEN SALTS

室温熔盐中的狄尔斯桤木反应

• 批准号: 6301676
• 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/6301676
• 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.

常温氯铝酸盐熔盐，AlCL/3：MCL，其中Mcl为 1-乙基-3-甲基-1H-咪唑氯(EMIC)或N-1- 氯化丁基吡啶(BPC)，从未被用作溶剂/催化剂 用于合成重要的Diels-Alder反应。这是令人遗憾的 因为人们可能会期待观察到不同寻常和有趣的[4pi+2pi]- 离子液体中的环加成反应。熔融盐的组成 可以很容易地从碱性(EMIC或BPC过量)变化到酸性(AlCL/3 超额)。熔盐的这种可变的刘易斯酸度是独一无二的 应该对Diels-Alder反应产生深远的影响。此外， 常温熔盐中的质子功能类似于Brphisted 具有Hammett酸度函数的超强酸，H/0，范围为-12.6(1.04： 1摩尔比AlCL/3-EMIC)至-18(2：1摩尔比AlCl/3-EMIC)。这 “双酸”介质应显著影响Diels-Alder 已知受刘易斯和布氏催化剂影响的反应。 这些酸催化剂不仅大大加快了反应速度，而且 还增强了非对映选择性和区域选择性。拟议的研究 涉及对环境的适宜性进行系统调查 温度熔盐作为Diels-Alder反应的溶剂/催化剂。 具体研究项目包括：(1)突出……潜力 常温熔盐作为内部和外部的有用溶剂 分子间Diels-Alder反应；(2)研究 溶剂的Lewis和Brphist酸度对Diels-Alder的影响 反应；(3)比较溶剂的刘易斯效应和布氏效应 Diels-Alder反应的速率和立体化学(4)鉴定 并表征了反应产物和中间体 各种内部和 熔盐介质中的分子间Diels-Alder反应； 研究熔融盐作为溶剂/催化剂的潜力 合成多种天然产物并具有生理活性 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。