1999 Alfred Bader Lecture. From Early Developments in Multi-Step Organic Synthesis on Solid Phase to Multi-Nuclear Phthalocyanines.

Early developments in solid phase organic synthesis are traced. Particular emphasis is placed on the use of cross-linked polystyrene in the first general method of monoblocking symmetrical difunctional compounds. The monoprotected polymer-bound symmetrical starting materials were then used in multi-step syntheses of a variety of compounds, particularly insect pheromones. Asymmetric synthesis on polymer supports was demonstrated. Diels-Alder and 1,3-dipolar additions on polymer supports proceeded readily as did macrocyclic formation of porphyrins and phthalocyanines. All of these reactions clearly showed that most organic chemical reactions could be performed on solid phases and laid the basis for the development of combinatorial chemistry. The first unsymmetrical phthalocyanine was prepared using the solid phase method and this led eventually to solution phase methods of preparing bi-, tri-, tetra-, and even a dendritic-like pentanuclear phthalocyanine.