The role of alcohol in the Yb(OTf)3- and Y(OTf)3-catalyzed stereoselective radical polymerization of acrylamides is clarified. The coordination of two equivalents of alcohol to the metal triflate generates a complex, which increases both the polymerization rate and stereocontrol compared to those without an alcohol. The importance of hydroxyl groups of the alcohol is suggested by the observed secondary isotope effect for the rate enhancement. The conditions are highly compatible with those for organotellurium-mediated radical polymerization, and the dual control of molecular weight and tacticity is successfully achieved.
- Beomsu Park
- Yuji Imamura
- Shigeru Yamago
