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Organocatalysts for the Controlled “Immortal” Ring‐Opening Polymerization of Six‐Membered‐Ring Cyclic Carbonates: A Metal‐Free, Green Process
Author(s) -
Helou Marion,
Miserque Olivier,
Brusson JeanMichel,
Carpentier JeanFrançois,
Guillaume Sophie M.
Publication year - 2010
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201001111
Subject(s) - trimethylene carbonate , carbonate , ring opening polymerization , chemistry , polymer chemistry , polymerization , phosphazene , benzyl alcohol , amine gas treating , guanidine , catalysis , molar mass , dimethyl carbonate , glycerol , ring (chemistry) , potassium carbonate , organic chemistry , polymer
Six‐membered cyclic carbonates, namely trimethylene carbonate (TMC), 3,3‐dimethoxytrimethylene carbonate (DMTMC) and 3‐benzyloxytrimethylene carbonate (BTMC), undergo controlled “immortal” ring‐opening polymerization (iROP) under mild conditions (bulk, 60–150 °C), by using organocatalysts, including an amine [4‐ N , N ‐dimethylaminopyridine (DMAP)], a guanidine [1,5,7‐triazabicyclo‐[4.4.0]dec‐5‐ene (TBD)], or a phosphazene [2‐ tert ‐butylimino‐2‐diethylamino‐1,3‐dimethylperhydro‐1,3,2‐diazaphosphorine (BEMP)], in the presence of an alcohol [benzyl alcohol (BnOH), 1,3‐propanediol (PPD), glycerol (GLY)] that acts as both a co‐initiator and a chain‐transfer agent. Remarkably, such organocatalysts remain highly active in the iROP of technical‐grade, unpurified TMC. Under optimized conditions, as much as 100 000 equivalents of TMC were fully converted by as little as 10 ppm of BEMP with the simultaneous growth of as many as 200 polymer chains, allowing the preparation of high molar mass poly(trimethylene carbonate)s (up to 45 800 g mol −1 ). These catalyst systems enable among the highest activities (TOF=55 800 h −1 ) and productivities (TON=95 000) ever reported for the ROP of TMC.