This project will explore several synthetic methods that rely on copper as the metal that effects catalysis. A number of the transformations are on copper hydride chemistry, which includes new uses of nonracemically ligated CuH for syntheses. The potential to realize unprecedented ligand-accelerated catalysis with CuH in pure water at room temperature will be pursued, along with the potential to deliver water-sensitive carbon-based residues via conjugate addition chemistry, with both approaches based on micellar catalysis in water. Heterogeneous processes that take advantage of both readily accessed valence states of copper [Cu(I) and Cu(II)] impregnated into the pores of inexpensive charcoal matrices will also be developed. A high substrate-to-ligand ratio and tandem processes that can be carried out in a single reaction vessel will be studied.
With this award, the Chemical Synthesis Program is supporting the research of Professor Bruce H. Lipshutz of the Department of Chemistry at the University of California, Santa Barbara. Professor Lipshutz's research efforts revolve around the development of organocopper-based asymmetric catalysis leading to new methods for the formation of C-C and C-H bonds. Such chemistry will contribute to environmentally benign methods for chemical synthesis as most of these new technologies will be developed in the absence of organic solvents, where water serves as the macroscopic medium. Successful applications of the methodology will have an impact on synthesis in the pharmaceutical, fine chemical, and agricultural industries.
Our four-year program emphasized the use of copper as a catalyst for effecting several new methodologies of potential value to the synthetic community. While most proposed were, in fact, realized under this award period, we were able to begin the transition of organocopper chemistry from traditionally being used in organic solvents to chemistry in water; i.e., in the complete absence of organic media. This new technology, which goes completely against established dogma in the field, documented that the use of inexpensive and newly engineered nanoparticles could be used in water to achieve the same net transformations. The rationale behind development of this new chemistry is simply that organic solvents constitute over 85% of the organic waste created in academic, industrial, and government labs worldwide, and the amounts per year are staggering. In order to make the venerable area of organic chemistry sustainable, a transition away from organic solvents and towards Nature; chemistry in water at ambient temperatures, must be developed. These concepts have now been shown to be not only achievable, but well-received by the pharmaceutical enterprise. Another outcome has been the development of a new green experiment for introductory organic labs that begins to illustrate how organic solvents can be totally avoided at this level of the educational process. It illustrates how Nobel Prize-winning chemistry ("click" reactions, by Nobel Laureate Barry Sharpless) can be carried out in water at room temperature. This experiment, catalyzed by copper, was published in the Journal of Chemical Education in 2013.
