The aza-Michael reaction as an alternative strategy to generate advanced silicon-based (macro)molecules and materials

Aza-Michael reaction is a simple and accessible addition reaction performed at moderate temperature, possibly without a catalyst and without releasing by-products. Its versatility allows designing specific structures thanks to the availability of a multitude of Michael acceptors and Michael donors. The reaction rate of the aza-Michael reaction can be improved by adding different co-reactants (polar protic solvents, catalysts) and/or adjusting the external energy sources (e.g. moderate to high temperatures or high pressures). Here, we show that this addition reaction is efficient for modifying or curing silicon-containing molecules, oligomers and polymers. The pros and cons of applying the aza-Michael reaction to silicon-containing molecules (including alkoxysilanes and PDMS) are highlighted. A large variety of intermediates such as coupling agents, reactive diluents, and sol-gel precursors prepared by the aza-Michael reaction are presented. Finally, applications of these, including products ranging from functional silicone intermediates to soft (unfilled) elastomers, are reported.