Synthetic Catalysts Based on Reversible Covalent Bond Formation

俄亥俄州立大学的安东尼·查尼克的这个项目属于有机动力学项目，将调查基于邻近效应的有机反应速率。将设计模型化学系统，使反应物和催化剂通过稳定的化学键结合在一起，这些化学键稍后可能通过已知的可逆化学反应打破。这项工作将增加对分子相互识别方式的了解。将继续开展基于可逆共价键形成的催化系统的开发工作，该催化系统将调解α，β-不饱和羰基化合物的合成转化。在这方面，将继续就酶模型和酶模拟的Diels-Alder方法开展工作。研究了咪唑并茂、四氮杂菲和2，5-双(TMEDA)呋喃加合物去除环加合物中配体和官能团之间的自由度的方法。反向Michael加成反应也将作为催化循环的基础，在比环加成过程低得多的温度下运行。基于“质子-海绵”结构的金属络合物(N，N，N‘-三甲基-1，8-二氨基萘)将被评估为Michael供体和作为激活的Michael加合物的一部分。还计划对金属催化的复古迈克尔反应进行分析。

This project by Anthony Czarnik of Ohio State University is within the Organic Dynamics Program, and will investigate the rate of organic reactions based on proximity effects. Model chemical systems will be designed so that reactants and catalysts will be brought together by stable chemical bonds which may later be broken through known, reversible chemical reactions. This work will lead to increased knowledge about the way molecules recognize one another. Work will be continued on the development of catalytic systems based on reversible covalent bond formation that will mediate synthetic conversions of alpha,beta-unsaturated carbonyl compounds. In this context, work will continue on the Diels-Alder approach to enzyme models and enzyme mimics. Methods to remove the degree of freedom between ligand and functional groups in cycloadducts will be investigated using bridged imidazole-anthracenes and tetraazaanthracene adducts, as well as the adducts with 2,5-bis(TMEDA)furan. The reverse Michael addition reaction will also be explored as a basis for catalytic cycles operating at much lower temperatures than the cycloaddition processes. Metal complexes based on the "proton- sponge" structure (N,N,N'-trimethyl-1,8-diaminonaphthalene) will be evaluated as Michael donors and as part of activated Michael adducts. An analysis of the metal-catalyzed retro Michael reaction is also planned.