Silylated Initiators for the Efficient Preparation of Borane-End-Functionalized Polymers via ATRP

Borane-end-functionalized polymers have been prepared through (i) atom transfer radical polymerization (ATRP) of styrene using a silylated initiator, 1-bromo-1-(4-trimethylsilylphenyl)ethane (PEB-SiMe 3 ), (ii) exchange of the SiMe 3 end groups with BBr 3, and (iii) modification of the Lewis acidic boron centers with nucleophiles. Ditelechelic α,ω-borane-functionalized polymers were obtained through atom transfer radical coupling (ATRC) of the silane-end-functionalized polymers followed by exchange with BBr 3 and subsequent reaction with nucleophiles. Self-assembly of the borane-functionalized mono- and ditelechelic polymers into supramolecular structures by means of reversible noncovalent and covalent interactions including Lewis acid−base complexation and boroxine formation has been explored.