A Switchable Domino Process for the Construction of Novel CO -Sourced Sulfur-Containing Building Blocks and Polymers.

α-Alkylidene cyclic carbonates (αCCs) recently emerged as attractive CO -sourced synthons for the construction of complex organic molecules. Herein, we report the transformation of αCCs into novel families of sulfur-containing compounds by organocatalyzed chemoselective addition of thiols, following a domino process that is switched on/off depending on the desired product. The process is extremely fast and versatile in substrate scope, provides selectively linear thiocarbonates or elusive tetrasubstituted ethylene carbonates with high yields following a 100 % atom economy reaction, and valorizes CO as a renewable feedstock. It is also exploited to produce a large diversity of unprecedented functional polymers. It constitutes a robust platform for the design of new sulfur-containing organic synthons and important families of polymers.