New Approaches for Seletivity in the Synthesis of Organic Compounds (Chemistry)

这项计划得到了有机化学和高分子化学计划的支持。这项工作的目标是满足日益增长的对具有理论和生物学意义的复杂有机分子的高效合成方法的需求。这项工作将产生新反应和新试剂形式的新工具。四个不同的领域涵盖了广泛的努力范围。一项主要的工作提出了这样一个问题：过渡金属络合物形式的简单分子实体是否可以像酶对活细胞所做的那样，作为选择性有机转化的催化剂。对烯丙基体系进行化学、区域、非对映和对映体选择性转化的操作将涉及到探索设计的包含Pd、Mo和W的配合物。不饱和官能团的分子内氨基甲酰化反应是环结构的一个新的令人兴奋的推动力。这种通过异构化进行分子变化的反应进入了一个设计反应以最大限度地减少化学废物从而最大限度地减少废物处置的时代。另一项发展设想了奇数环的一般环加成方法，与极其重要的Diels-Alder反应形成对比。双功能试剂不会自湮灭，但可以被过渡金属模板激活，为这种发展提供了基础。有机硫化合物出人意料的反应性为多方面的反应提供了一个独特的机会。这些试剂成为“化学变色龙”，因为它们可以完全在两种相反类型的反应之间相互转换，这取决于它们所处的环境。它们还为不对称合成提供了一种独特的方法。最后一节讨论了基于应变和反应性的伙伴关系来设计复合官能团或“假官能团”的概念。

This program is being supported by the Organic and Macromolecular Chemistry Program. The goal of the work is to meet the increasing demand for efficient synthetic approaches to complex organic molecules of theoretical and biological interest. New tools in the form of new reactions and reagents will result from this work. Four diverse areas cover a broad scope of endeavor. A major effort asks the question of whether simple molecular entities in the form of transition metal complexes can serve as catalysts for selective organic transformations in a fashion analogous to what enzymes do for the living cell. Manipulation of allyl systems for chemo-, regio-, diastereo-, and enantioselective transformations will involve exploring designed complexes embracing Pd, Mo, and W. Intramolecular carbametallation of unsaturated functional groups represents a new exciting thrust for ring construction. Such reactions involving molecular change by isomerization enters an era of designing reactions for minimizing chemical waste and therefore minimizing disposal. Another development envisions a general cycloaddition approach to odd membered rings in contrast to the extremely import Diels-Alder reaction. Bifunctional reagents which do not self-annihilate but may be activated by transition metal templates provide the basis for such a development. Unexpected reactvity of organosulfur compounds provides a unique opportunity for multifaceted reactivity. These reagents become "chemical chameleons" since they can totally interconvert between two opposing types of reactivity depending upon their environment. They also offer a unique approach for asymmetric synthesis. The final section deals with the concept of designing composite functional groups or "pseudofunctional groups" based upon a partnership of strain and reactivity.