Efficient Metathesis Polymerizations Through Rational Design of Monomers: Cyclopolymerization of Diyne Derivatives Forming Small-to-Medium Rings and Ring-Opening Metathesis Polymerization of cis-Cyclooctenes

Abstract

Olefin metathesis is a widely-used organic reaction to generate new carbon-carbon double bond by metal carbene . Above all, ring-opening metathesis polymerization (ROMP) is a representative chain growth metathesis polymerization for living polymerization. Cyclopolymerization (CP) is another chain-growth metathesis polymerization forming conjugated polyacetylene (PA) from diynes. To widely utilize cyclopolymerization generating PA derivatives having potential for organic electronics and optics, broader monomer scope and higher reactivity are required. This research describes the living/controlled CP of 1,7-octadiyne and 1,8-nonadiyne derivatives and Ring-Opening Metathesis Polymerization (ROMP) of cis-cyclooctenes through the rational design of monomers. Chapter 2 describes the CP of N-containing 1,7-octadiyne derivatives using Grubbs catalyst. Introduction of hydrazide group having short C-N bond and enhanced Thorpe-Ingold effect enabled us to achieve living CP of 1,7-octadiynes. Chapter 3 demonstrates the first CP of 1,8-nonadiyne derivatives using Grubbs catalyst. 1,8-nonadiyne was first utilized as a monomer for CP by introduction of aminal and acetal groups. CP of 1,8-nonadiyne derivatives showed zeroth-order kinetics different from conventional polymerizations. Interestingly, we observed the active intermediate of olefin metathesis, 14e-Ru propagating carbene during CP. Chapter 4 describes two strategies for controlled ROMP of cis-cyclooctenes. Although effect of bulky substituent was small for hindering chain transfer reaction, controlled ROMP of OTIPS-substituted cyclooctene was achieved.