Progress toward new catalysts for acyclic diene metathesis (ADMET) polymerization reactions

Abstract

The compounds Tp′W(CHR)(E)X (Tp′= hydridotris(3,5-dimethylpyrazolyl)borate; RCMe 3, Ph; EO, NPh; XCl, Br), 4a–c, have been synthesized by reaction of Tp′W(CR)X 2, (R CMe 3, XCl; RPh, XBr), 3a, b, with neutral alumina or aniline. Compounds 3a, b and 4a–c are air stable and thermally stable to ⪢ 100 °C in the solid state. When combined with 1 equivalent of AlCl 3, Tp′W(CHPh)(NPh)Br, 4c, catalyzes the acyclic diene metathesis (ADMET) oligomerization of 1,9-decadiene, giving a mixture of 1,9,17-octadecatriene, 1,9,17,25-hexadodecatetraene and ethylene (≈30% conversion). The new alkylidene complex, 4a, is an efficient ring-opening metathesis polymerization (ROMP) catalyst in the presence of AlCl 3, as a co-catalyst.