Jimmy Wu
Assistant Professor of Chemistry
Professor Wu received his A.B. degree in Chemistry from Princeton University in 1998. He then spent two years as an associate chemist at Merck Process Research where he worked on the development of selective COX-II inhibitors. Afterwards, he moved to Harvard University where he obtained his Ph.D. in organic chemistry from Professor David A. Evans. His doctoral work focused on asymmetric catalysis using lanthanide-pybox complexes. He continued his studies as a postdoctoral fellow with Professor Barry M. Trost at Stanford University where he worked on the synthesis of indoline alkaloid communesin B. Dr. Wu will join the faculty of Dartmouth College in the summer of 2007.
Research Interests
In the past decade, the field of organocatalysis has experienced tremendous growth. However, in comparison to metal-based asymmetric catalysis, the field of organocatalysis remains vastly underdeveloped. The use of organocatalysts offers several advantages over its metal counterparts such as unique reactivity and selectivity profiles as well as greater functional group compatibility. In addition, organocatalysts present fewer toxicity issues and are often easier to handle with regards to oxygen and moisture sensitivity. My group is interested in extending the field of organocatalysis with the broadly defined purpose of solving problems that have been difficult for traditional metal catalysts to address.
1. Organocatalytic Enantioselective SN1 Reactions: Every student who has taken sophomore organic chemistry is familiar with the SN1 reaction. Because the mechanism of this transformation proceeds through a planar carbocation intermediate, any pre-existing stereochemical information at the reacting carbon is irrevocably lost. We are interested in developing catalysts capable of promoting asymmetry for reactions in which the enantio-discriminating step is the trapping of a prochiral carbocation (e.g. SN1 reactions). Because carbocations are inherently Lewis acidic in nature, traditional chiral metal-based Lewis acids cannot be implemented for this purpose. My group is interested in exploring the use of novel organocatalysts as a means for solving the generalized challenge of trapping prochiral carbocations in an enantioselective fashion. The solution to this problem will have wide-ranging applications that extend far beyond the simple SN1 reaction since any transformation which proceeds through a carbocation intermediate can potentially be rendered asymmetric using this method.
2. Organocatalytic Enantioselective Claisen Reactions: The products of the Claisen rearrangement are extremely useful because they are masked dicarbonyl compounds which possess a 1,4 relationship. There are few methods available for preparing chiral 1,4-dicarbonyl compounds. In fact, many of the reactions which furnish these types of products require an umpolung of reactivity. Despite the advances that chemists have achieved in asymmetric catalysis over the past two decades, a general enantioselective metal-catalyzed variant of the Claisen rearrangement has yet to be discovered. We are interested in using organocatalysts to promote catalytic asymmetric Claisen rearrangements. The development of an efficient and general asymmetric Claisen rearrangement can be applied to the stereoselective total syntheses of natural products containing the 1,4-dicarbonyl motif.
3. Chiral C2-Symmetric Urea and Thioureas: In the past several years, a few research groups have begun to use chiral C1-symmetric ureas and thioureas, capable of simultaneously donating two hydrogen-bonds, to catalyze asymmetric organic transformations. Although some impressive results have been achieved thus far, the field of hydrogen-bond promoted organocatalysis remains in its infancy. The concept of C2-symmetry in catalyst design is extremely powerful because the added symmetry element serves as a mechanism to reduce the number of possible competing, diastereomeric transition states when compared with non-symmetrical catalysts. This research project is concerned with the development of C2-symmetric, bifunctional chiral urea and thiourea catalysts and their application to enantioselective transformations.
