Organic Catalysis: A Broadly Useful Strategy for Controlled Polymerization Reactions

本研究的重点是发展应变酯活性开环聚合的一般有机催化策略。 本文将考察噻唑、咪唑和咪唑啉类亲核卡宾催化剂在张力环状单体和其它单体体系中的聚合反应。 此外，我们还将研究咪唑啉-2-亚基衍生物与活化C-H键的C-H插入反应，得到对空气稳定的卡宾。 所使用的原位方法将提供催化剂库的快速筛选，以基本了解催化剂结构对聚合速率、控制程度、底物耐受性和这些策略可获得的分子量范围的影响。 机理研究将解决单体活化与酯交换的相对速率，以定义可预期良好控制聚合的动力学窗口。 这种有机催化方法的延伸，以开环的内酰胺和酯交换的磷酸酯也将进行研究。 有了这个奖项，有机和高分子化学计划和多学科活动办公室正在支持博士罗伯特M。斯坦福大学化学系的Weymouth和James L. IBM研究院的赫德里克。 该合作将把研究重点放在开发用于活性聚合过程的有机催化剂上。 该项目将开发用于可控聚合反应的新合成方法，获得酯交换反应亲核催化的新见解，并开发用于精细化学品合成的新型有机催化剂。 该项目将使研究生和博士后能够在学术和工业实验室之间高度跨学科的合作努力中得到培训，而且在创造更清洁的环境方面，这项工作还有可能产生更广泛的影响。

The focus of this research involves the development of general organocatalytic strategy for the living ring opening polymerization of strained esters. Nucleophilic carbene catalysts from thiazolium, imidazolium and imidazolinium families will be examined for the polymerization of strained cyclic monomers and other monomer systems. Further, a variety of C-H insertion reactions will be studied using imidazolin-2-ylidines with activated C-H bonds to afford air stable carbenes. The in situ methodology used will provide for rapid screening of libraries of catalysts to give basic understanding of catalyst structure on polymerization rates, the degree of control, the substrate tolerance and range of molecular weights accessible with these strategies. Mechanistic investigations will address the relative rate of monomer activation versus transesterification to define the kinetic window where well-controlled polymerization can be expected. Extension of this organocatalytic method to the ring opening of lactams and transesterification of phosphate esters will also be investigated. With this award, the Organic and Macromolecular Chemistry Program and the Office of Multidisciplinary Activities are supporting the GOALI project of Dr. Robert M. Weymouth of the Department of Chemistry at Stanford University and Dr. James L. Hedrick of IBM Research. The collaboration will focus research efforts on developing organic catalysts for use in living polymerization processes. The project will develop new synthetic methods for controlled polymerization reactions, obtain new insights into nucleophilic catalysis of transesterification reactions and develop a new class of organocatalysts for use in fine chemical synthesis. The project will enable the training of graduate students and a postdoctoral in a highly interdisciplinary, collaborative effort between an academic and an industrial laboratory and there is further potential for broader impact of the work in terms of creating a cleaner environment.