Geometrical Aspects of the Activation of Carbonyls by Lewis Acids

羰基/刘易斯酸配合物的中间体几何构型 亲核加成反应 酮，与烯酮的共轭亲核加成，以及2 + 将研究4个环加成。 小心使用 设计的金刚烷酮、十氢萘酮和空间定向十氢萘酮 系统，控制各种刘易斯酸的π结合 将通过测量 以及由此产生的对化学反应性的影响。的 1，2-和1，4-亲核加成反应速率和2 + 将测量其中刘易斯 与酮部分结合的酸与酮在平面内 以及经由π-复数型几何形状。 差异 基于过渡族和主族金属的刘易斯酸将 评估，饱和与不饱和的影响 羰基化合物对刘易斯酸的热力学偏好 将定义络合几何形状。 %%% 现代化学研究最重要的方面之一 是在分子水平上定义加速 反应，并提供清洁，高效的生产， 有针对性的产品。 这项来自有机组织的拨款 动力学计划支持继续调查 三种重要化学反应的酸催化 教授R。C.科科伦在怀俄明州大学。 的 研究的目标是化学物种的合成 具有提供特定结合的几何约束， 金属酸催化剂这些过程在以下方面至关重要 设计新的催化剂，提高效率，并将 在控制合成过程中具有显著的益处 技术重要性。

The intermediate geometry of carbonyl/Lewis acid complexes in reactions encompassing nucleophilic addition to saturated ketones, the conjugate nucleophilic addition to enones, and 2 + 4 cycloadditions will be investigated. By use of carefully designed adamantone, decalone, and sterically-directed decalone systems, the controlled pi-binding of a variety of Lewis acids to the carbonyl center will be studied by measuring the extent of binding and the resultant effect on chemical reactivity. The reaction rates of 1,2- and 1,4- nucleophilic additions and 2 + 4 cycloadditions will be measured for systems in which Lewis acid binding to the ketone moiety is in-plane with the ketone as well as via a pi-complex type geometry. Differences between transition and main group metal based Lewis acid will be evaluated, and the effect of saturated versus unsaturated carbonyls on the thermodynamic preference for Lewis acid complexation geometry will be defined. %%% One of the most important aspects of modern chemical research is to define on a molecular level the factors which accelerate reactions and provide for clean, efficient generation of specific targeted products. This grant from the Organic Dynamics Program supports the continuing investigation of the acid catalysis of three important classes of chemical reactions by Professor R. C. Corcoran at the University of Wyoming. The investigation is targeted toward synthesis of chemical species with geometrical constraints that provide specific binding of metallic acid catalysts. Such processes are critical in designing new catalysts with increased efficiency, and will be of significant benefit in controlling synthetic processes of technical importance.