Solid phase supported chemistry

Since Merrifield's pioneering work in solid-phase peptide synthesis, which won him the Nobel Prize in 1963, supported organic synthesis has enjoyed steady popularity and development. The solid phase was first applied to the oligomeric synthesis of natural products such as polypeptides, polysaccharides and oligonucleotides. It was the work of Fréchet and Leznoff, in the late 1970s, that initiated its use in the synthesis of small molecules by carrying out organic reactions in which a substrate, reagent or catalyst was grafted onto an insoluble solid polymer. Another application is the purification of reaction mixtures using scavengers attached to solid supports. A large number and variety of organic reactions have been successfully transposed to the solid phase, leading to the development of combinatorial and then parallel synthesis in the 1990s.

Solid-phase chemistry limits the use of toxic, flammable solvents, reducing their production and disposal, as it reduces purification steps to simple solid/liquid filtrations. The polymer is recyclable, which reduces waste. Chemical synthesis is less dangerous and less harmful, thanks to the high chemical and physical stability of the supports. Microwave, ultrasonic and high-pressure activations have been demonstrated, as has the positive influence of green solvents such as ionic liquids. Finally, the toxicity or volatility of grafted compounds is minimal, helping to prevent accidents, illnesses, explosions and fires. For all these reasons, solid-phase chemistry has its place in the concept of green chemistry.