New Organometallic Catalysts for Multistep Coupling Reactions

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Our research during the last 6 years has led to discoveries in several different areas of transition metal catalysis. These include: a) the observation that metal catalyzed aryl halide carbonylations can be used in a new direction: the assembly of high energy electrophiles (acid chlorides); b) the use of metal catalysis to convert of multiple available reagents in one step into products; c) an alternative approach to prepare conjugated polymers without a complex synthesis: a metal catalyzed multicomponent polymerization; d) new and modular classes of 1,3-dipoles for application in cycloaddition; and e) the use of weak forces such as ion pairing to design active and (enantio)selective metal catalysts. Together, these suggest the potential to form products as diverse as complex pharmaceutical cores or advanced polymers from simple combinations of available reagents brought together at once, as well as new approaches to functionalize hydrocarbons. This proposal will develop this chemistry in three directions, including: Carbonylative Electrophile Synthesis Our discovery that palladium catalyzed aryl halide carbonylations can be used to synthesize acid chlorides shows that it is possible to use simple carbon monoxide not simply as a reagent, but as a compound that can drive the build-up of high energy products. In this proposal, we will examine the potential of exploiting this platform as a general method to synthesize acid chloride electrophiles or even super electrophiles, and to perform hydrocarbon functionalization into ketones, all driven by the reactivity of carbon monoxide. One Step Routes to Biologically Relevant Products We will build upon our recent research efforts to use metal catalysis to develop simple, one step methods to assemble biologically relevant core structures directly from available building blocks. Because of their efficiency, these reactions can be not only straightforward to perform, but also minimize waste, and can prove ideal for creating new variants of bio-active compounds. These efforts will include creating both new classes of these catalytic reactions, and the potential application of these to directly construct important pharmaceutical structures via catalysis. Multicomponent Polymerizations We have recently discovered a new method to assemble complex polymers in an efficient fashion: by coupling several simple monomers directly into a new polymer (a metal catalyzed multicomponent polymerization). This can provide an approach to form complex polymers in a practical manner, and will be directed towards generating new classes of conjugated polymers, modular methods to access polyamides, as well as the creation of novel polymer libraries to tune their properties.