Michigan State University
During the past 20 years, we have witnessed a great deal of activity directed towards the use of Exciton Coupled Circular Dichroism (ECCD) for the absolute stereochemical determination of organic molecules. The porphyrin tweezer method was among a number of innovative strategies that highlighted the power of ECCD analysis in host/guest complexation of chiral molecules. The use of a variety of zincated porphyrin tweezers as the chromophoric hosts will be discussed, with demonstration of the methodology’s feasibility for the absolute stereochemical determination of a number different classes of organic molecules. Application of a new host system, capable of binding molecules with a single site of attachment will be discussed also, with applications for absolute stereochemical determination of amines, cyanohydrins, alcohols, sulfoxides, phosphine oxides, etc. Finally, we will explore using these host systems for ‘programmable’ catalytic asymmetric synthesis.