Functionalization vs. degradation of 1,4-polybutadiene by ruthenium complex catalyzed reaction with vinylsilanes

Polybutadiene (I) containing 91% of 1,4-(cis-trans) units and 9% of 1,2-uni ts in the presence of vinyltriethoxysilane (II) and ruthenium catalysts RuC l2(PPh3)(3) (III), RuHCl(CO)(PPh3)(3) (IV), and [RuCl2(CO)(3)](2) (V) at 10 0-130degreesC undergoes functionalization and (or) partial degradation as a n effect of competitive silylative coupling of =C-H and cross-metathesis of I with II. Significant degradation of I occurs at lower temperatures (100- 110 degreesC) (particularly when the process is carried out in air), but ex clusive functionalization of I is observed at higher temperature (120-130de greesC) regardless ofthe atmosphere (air or argon) used.