New Metal Catalyzed Organic Transformations

有机合成计划支持K·巴里·夏普莱斯博士的工作。麻省理工学院化学教授夏普莱斯继续他对有机合成新试剂的开创性研究。他目前的工作在一定程度上是为了研究金属如何与分子中现有的基团络合，从而将新的反应引导到特定的位置。值得注意的新方向包括尝试开发不需要现有系绳来指导化学作用的方法。夏普莱斯的团队继续研究配体加速催化反应的机理细节，以及这如何导致观察到的反应的显著对映选择性。作为他的机理研究的一部分，他最近发现了一种无需试剂事先与底物结合的方法来对孤立的烯键进行二羟基化。这一发现为科学研究开辟了一个全新的领域，并对合成化学家具有巨大的潜力。他的团队也在试图理解这一过程的起源。夏普莱斯将“梳理元素周期表”，寻找新的试剂添加到合成化学家已有的武器库中。最初的审查将是寻找独特的金属/过氧化氢组合，以对孤立的烯烃进行不对称环氧化。一种独特的分析系统，与用于筛选分子生物活性的系统类似，将被用于检查大系列的反应。

The Organic Synthesis Program supports the work of Dr. K. Barry Sharpless. Sharpless, Prof. of Chemistry at MIT, continues his pioneering investigations of new reagents for organic synthesis. His current work is, in part, directed towards examining how metals complex to existing groups in a molecule to direct new reactions to a particular site. Notable new directions include trying to develop methods that do not require an existing tether to direct the chemistry. Sharpless's group continues to investigate the mechanistic details of ligand-accelerated catalysis of reactions, and how this leads to the remarkable enantioselectivity observed for the reactions. As part of his mechanistic investigations he has recently discovered a process for dihydroxylating an isolated alkene bond without prior binding of the reagent to the substrate. This discovery opens a whole new arena for scientific enquiry, and has great potential for synthetic chemists. His group is trying to also understand the origins of this process. Sharpless will "comb the periodic table" looking for new reagents to add to the arsenal already available to the synthesis chemist. Initial scrutiny will be given to finding unique metal/ hydroperoxide combinations to carry out asymmetric epoxidation to isolated alkenes. A unique assay system, analgous to that used for screening for bioactivity of molecules, will be employed to examine large series of reactions.