Geometry of the porphyrin trimer catalyst

C. J. Walter , H.L. Anderson and J. K. M. Sanders report the catalysis of the Diels-Alder addition of a furan-based diene and a maleimide based dienophile using the porphyrin trimer catalyst shown to the right. This system was inspired by biological enzymes. It functions by providing unusual types of "anchors" for the two substrates, which are thus forced into proximity and caused to react. The design and use of such "un-biological" systems but based on enzymic principles is leading chemistry into entirely novel and uncharted areas!
Prepared by Sylvain Comiti. June 1996.