A strategy combining quantitative reactions and reversible-covalent chemistry for sequential synthesis of sequence-controlled polymers with different sequences

A new strategy combing quantitative reactions and reversible-covalent chemistry is proposed for sequential synthesis of a series of sequence-controlled polymers with different sequences. Using a Michael addition reaction between acrylate and thiol, an aminolysis reaction of five-membered cyclic dithiocarbonate and a thiol substitution reaction of bromomaleimide and thiol, AB-, AB'C- and AB'CD-sequenced molecules are synthesized via AB, AB'C and AB'CD sequential monomer additions, respectively. These three molecules all have furan-protected maleimido group at one end, and the other end of AB-, AB'C- and AB'CD-sequenced molecules is amine, thiol and anthracene groups, respectively. Due to the fact that the furan-protected maleimido group can be efficiently transformed to maleimide group at high temperature via retro Diels-Alder reaction, AB-, AB'C- and AB'CD-sequenced molecules polymerize into sequence-controlled polymers with corresponding sequences at 120 °C. Through this strategy, the synthesis of molecular modules does not require separation and purification, and sequence-controlled polymers with specific sequence can be synthesized in a one-pot process via adding different monomers and adjusting reaction condition.