Sequential Phosphine-Catalyzed, Nucleophilic Thiol-Ene/Radical-Mediated Thiol-Yne Reactions and the Facile Orthogonal Synthesis of Polyfunctional Materials

摘要

The thiol-ene reaction has recently attracted significant attention in the materials arena, as it displays many of the attributes of click chemistry. Hawker and co-workers have highlighted its application in dendrimer synthesis, while Chan et al. have described a macromolecular version in convergent star synthesis. Dove and co-workers described its use in preparing functional biodegradable polylactides, and Schlaad and co-workers utilized it to modify side chains of poly[2-(3-butenyl)-2-oxazoline], while Rissing and Son detailed the synthesis of branched organosilanes with a range of functional thiols. Importantly, it should be noted that the thiol-ene reaction proceeds under a variety of experimental conditions, including acid/base catalysis, nucleophilic catalysis, radical mediation (most commonly under photochemical conditions), and via a solvent-promoted process. The real strength of the thiol-ene reaction is the broad range of ene substrates that readily undergo hydrothiolation, including activated and nonactivated species.