om8b00678_si_001.pdf (36.89 MB)
Alkyne [2 + 2 + 2] Cyclotrimerization Catalyzed by a Low-Valent Titanium Reagent Derived from CpTiX3 (X = Cl, O‑i‑Pr), Me3SiCl, and Mg or Zn
journal contributionposted on 2018-10-29, 19:37 authored by Sentaro Okamoto, Takeshi Yamada, Yu-ki Tanabe, Masaki Sakai
Inter-, partially intra-, and intramolecular [2 + 2 + 2] cycloadditions of alkynes were catalyzed by a low-valent titanium species generated in situ from the reduction of CpTi(O-i-Pr)3, CpTiCl3, or Cp*TiCl3 with Mg or Zn powder in the presence of Me3SiCl. The role of Me3SiCl as an additive in the reaction mechanism is discussed.