Geometrical Aspects of the Activation of Carbonyls by Lewis Acids

在包括饱和酮的亲核加成、烯酮的共轭亲核加成和2+4环加成的反应中，将研究羰基/Lewis酸络合物的中间几何构型。通过使用精心设计的金刚烷酮、十酮和立体定向十酮系统，将通过测量结合程度和由此产生的对化学反应活性的影响来研究各种Lewis酸与羰基中心的受控pi结合。1，2-和1，4-亲核加成以及2+4环加成的反应速率将被测量，在这些体系中，Lewis酸与酮部分结合在平面上，并且通过pi-络合物类型的几何结构。将评估过渡金属和主族金属路易斯酸之间的差异，并定义饱和和不饱和羰基对Lewis酸络合几何构型热力学偏好的影响。%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的因素，并提供清洁、有效的特定目标产物的生成。有机动力学项目的这笔赠款支持怀俄明大学的R.C.科克伦教授继续研究三类重要化学反应的酸催化作用。这项研究的目标是合成具有几何约束的化学物种，以提供金属酸催化剂的特定结合。这些工艺对设计效率更高的新型催化剂至关重要，并将在控制具有重要技术意义的合成工艺方面发挥重大作用。

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.