Scavenger Templates: Synthesis and Electrospray Mass Spectrometry of a Linear Porphyrin Octamer

To avoid mixtures that are difficult to separate in the synthesis of oligomeric compounds, scavenger templates are invaluable. The schematic reaction below depicts how the template (in black) hinders side reactions in the dimerization of 2 to 4 from a reaction mixture including 1 and 2 —one has two reactive ends and the other only one—by rapidly cyclizing 1 to 3 ; in effect the template prevents the reaction of 1 with 2 and the dimerization of 1 (and subsequent reactions). The performance of the methodology is demonstrated for the synthesis of a porphyrin octamer.