Polymer synthesis by enzymatic catalysis.

Using biocatalysts as enzymes for in vitro polymer synthesis is a relatively new (third) stream that has become popular in the past two decades, following a first stream using catalysts of acids, bases, radical species, and so on, used since 1920s, and a second stream using catalysts of transition metals and rare metals since 1950s. Enzymatic catalysis is environmentally benign, yet allows the synthesis of various natural and unnatural polymers that have well-defined structures with controlled stereochemistry, regioselectivity, and chemoselectivity. This review will focus on recent developments in enzyme-catalyzed polymer synthesis in the areas of polysaccharides, polyesters, and polyaromatics, as well as polymer modification.