One-step synthesis of sequence-controlled multiblock polymers with up to 11 segments from monomer mixture

Switchable polymerization holds considerable potential for the synthesis of highly sequence-controlled multiblock. To date, this method has been limited to three-component systems, which enables the straightforward synthesis of multiblock polymers with less than five blocks. Herein, we report a self-switchable polymerization enabled by simple alkali metal carboxylate catalysts that directly polymerize six-component mixtures into multiblock polymers consisting of up to 11 blocks. Without an external trigger, the catalyst polymerization spontaneously connects five catalytic cycles in an orderly manner, involving four anhydride/epoxide ring-opening copolymerizations and one L-lactide ring-opening polymerization, creating a one-step synthetic pathway. Following this autotandem catalysis, reasonable combinations of different catalytic cycles allow the direct preparation of diverse, sequence-controlled, multiblock copolymers even containing various hyperbranched architectures. This method shows considerable promise in the synthesis of sequentially and architecturally complex polymers, with high monomer sequence control that provides the potential for designing materials.

CH2Cl2 solution into cold methanol. The purified polymers were dried under vacuum at room temperature for the next analysis.
The polymerization from the mixture of DPMA and BO catalyzed by the cesium pivalate A typical procedure is presented as follows: In an argon-filled glovebox, cesium pivalate (0.02 mmol, 1 equiv.), BDM (0.04 mmol, 2 equiv.), DPMA (0.5 mmol, 25 equiv.), and BO (5 mmol, 250 equiv.) were placed in an oven-dried reaction vessel with a magnetic stir. The reaction mixture was stirred at 100 °C under an argon atmosphere in an oil bath. During polymerization, a crude aliquot was time-regularly obtained from the system by a syringe in an argon flow and monitored by 1 H NMR spectroscopy and SEC to determine monomer conversion and molar mass. After the defined time, the polymerization was terminated by diluting the reaction mixture with dichloromethane (CH2Cl2). The reaction mixture was purified by reprecipitation from a CH2Cl2 solution into cold methanol. The purified polymers were dried under vacuum at room temperature for the next analysis.
The polymerization from the mixture of DPMA, L-Lactide (L-LA), and BO catalyzed by the cesium pivalate A typical procedure is presented as follows: In an argon-filled glovebox, cesium pivalate (0.02 mmol, 1 equiv.), BDM (0.04 mmol, 2 equiv.), DPMA (0.5 mmol, 25 equiv.), L-LA (1.0 mmol, 50 equiv.), and BO (5 mmol, 250 equiv.) were placed in an oven-dried reaction vessel with a magnetic stir. The reaction mixture was stirred at 100 °C under an argon atmosphere in an oil bath. During polymerization, a crude aliquot was time-regularly obtained from the system by a syringe in an argon flow and monitored by 1 H NMR spectroscopy and SEC to determine monomer conversion and molar mass. After the 6 The polymerization from the mixture of DGA, SA, NA, L-LA, DPMA and BO catalyzed by the cesium pivalate A typical procedure is presented as follows: In an argon-filled glovebox, cesium pivalate (0.02 mmol, 1 equiv.), BDM (0.04 mmol, 2 equiv.), DGA (0.5 mmol, 25 equiv.), SA (0.5 mmol, 25 equiv.), NA (0.5 mmol, 25 equiv.), L-LA (1.5 mmol, 75 equiv.), DPMA (0.25 mmol, 12.5 equiv.), and BO (7 mmol, 350 equiv.) were placed in an oven-dried reaction vessel with a magnetic stir. The reaction mixture was stirred at 80 or 100 °C under an argon atmosphere in an oil bath. During polymerization, a crude aliquot was time-regularly obtained from the system by a syringe in an argon flow and monitored by 1 H NMR spectroscopy and SEC to determine monomer conversion and molar mass. After the defined time, the polymerization was terminated by diluting the reaction mixture with dichloromethane (CH2Cl2). The reaction mixture was purified by reprecipitation from a CH2Cl2 solution into cold methanol. The purified polymers were dried under vacuum at room temperature for the next analysis.
The polymerization from the mixture of DGA, SA, L-LA, DPMA and BO catalyzed by the cesium pivalate A typical procedure is presented as follows: In an argon-filled glovebox, cesium pivalate (0.02 mmol, 1 equiv.), BDM (0.04 mmol, 2 equiv.), DGA (0.5 mmol, 25 equiv.), SA (0.5 mmol, 25 equiv.), L-LA (1.5 mmol, 75 equiv.), DPMA (0.25 mmol, 12.5 equiv.), and BO (7 mmol, 350 equiv.) were placed in an oven-dried reaction vessel with a magnetic stir. The reaction mixture was stirred at 100 °C under an argon atmosphere in an oil bath. During polymerization, a crude aliquot was time-regularly obtained from the system by a syringe in an argon flow and monitored by 1 H NMR spectroscopy and SEC to determine monomer conversion and molar mass. After the defined time, the polymerization was terminated by diluting the reaction mixture with dichloromethane (CH2Cl2). The reaction mixture was purified by reprecipitation from a CH2Cl2 solution into cold methanol. The purified polymers were dried under vacuum at room temperature for the next analysis. A typical procedure is presented as follows: In an argon-filled glovebox, cesium pivalate (0.02 mmol, 1 equiv.), PEG2000 (0.04 mmol, 2 equiv.), DGA (0.5 mmol, 25 equiv.), SA (0.5 mmol, 25 equiv.), NA (0.5 mmol, 25 equiv.), L-LA (1.5 mmol, 75 equiv.), DPMA (0.25 mmol, 12.5 equiv.), and BO (7 mmol, 350 equiv.) were placed in an oven-dried reaction vessel with a magnetic stir. The reaction mixture was stirred at 80 or 100 °C under an argon atmosphere in an oil bath. During polymerization, a crude aliquot was time-regularly obtained from the system by a syringe in an argon flow and monitored by 1 H NMR spectroscopy and SEC to determine monomer conversion and molar mass. After the defined time, the polymerization was terminated by diluting the reaction mixture with dichloromethane (CH2Cl2). The reaction mixture was purified by reprecipitation from a CH2Cl2 solution into cold methanol. The purified polymers were dried under vacuum at room temperature for the next analysis.
The polymerization from the mixture of TA, NA, L-LA, DPMA and BO catalyzed by the cesium pivalate A typical procedure is presented as follows: In an argon-filled glovebox, cesium pivalate (0.02 mmol, 1 equiv.), BDM (0.04 mmol, 2 equiv.), TA (0.5 mmol, 25 equiv.), NA (0.5 mmol, 25 equiv.), L-LA (1.0 mmol, 50 equiv.), DPMA (0.25 mmol, 12.5 equiv.), and BO (7 mmol, 350 equiv.) were placed in an oven-dried reaction vessel with a magnetic stir. The reaction mixture was stirred at 80 °C under an argon atmosphere in an oil bath. During polymerization, a crude aliquot was time-regularly obtained from the system by a syringe in an argon flow and monitored by 1 H NMR spectroscopy and SEC to determine monomer conversion and molar mass. After the defined time, the polymerization was terminated by diluting the reaction mixture with dichloromethane (CH2Cl2). The reaction mixture was purified by reprecipitation from a CH2Cl2 solution into cold methanol. The purified polymers were dried under vacuum at room temperature for the next analysis.
The polymerization from the mixture of TA, NA, and BO catalyzed by the cesium pivalate A typical procedure is presented as follows: In an argon-filled glovebox, cesium pivalate (0.02 mmol, 1 equiv.), BDM (0.04 mmol, 2 equiv.), TA (0.5 mmol, 25 equiv.), NA (0.5 mmol, 25 equiv.), and BO (3 mmol, 150 equiv.) were placed in an oven-dried reaction vessel with a magnetic stir. The reaction mixture was stirred at 80 °C under an argon atmosphere in an oil bath. During polymerization, a crude aliquot was time-regularly obtained from the system by a syringe in an argon flow and monitored by 1 H NMR spectroscopy and SEC to determine monomer conversion and molar mass. After the defined time, the polymerization was terminated by diluting the reaction mixture with dichloromethane (CH2Cl2). The reaction mixture was purified by reprecipitation from a CH2Cl2 solution into cold methanol.
The purified polymers were dried under vacuum at room temperature for the next analysis.  Table 1). NA with EGE was performed at 100 ℃ (entry 1 in Table 1 Table 1).  Table 1).  Table 1).  Table 1).

Reactivity ratio of DGA and NA
Since the nonterminal copolymerization kinetics are common in coordination−insertion, ionic, and pseudo ionic type polymerization mechanisms, we employed the simple model   Table 1).  Table 1).  Table   1).  Table 1).   Table 1).  Table 1).

Supplementary
system for monitoring the conversion of DGA, SA, NA, DPMA, L-LA, and the formation of resultant polymers. Red line (entry7 in Table 1) and black line (entry 8 in Table 1).  Table 1) and black line (entry 8 in Table 1).  Table 1) and black line (entry 8 in Table 1 Table 1).  Table 1).