Reactions of Ruthenium Complexes Containing Pentatetraenylidene Ligand.
Two ruthenium acetylide complexes [Ru]-C≡C-C≡C-C(OR)(C3H5)2(2, R=H and 2 a, R=CH3; [Ru]=Cp(PPh3)2Ru) each with two cyclopropyl rings were synthesized from TMS-C≡C-C≡C-C(OH)(C3H5)2(1; TMS=trimethylsilyl). Treatments of 2 and 2 a with allyl halide in the presence of KPF6afforded the vinylidene complexes 3 and 3 a, respectively. When NH4PF6was used, instead of KPF6, additional ring-opening reaction took place on one of the three-membered ring. Treatment of [Ru]Cl with 1,3-butadiyne (6), bearing an epoxide ring, afforded acetylide complex 7 with a furyl ring. Treatment of 2 a with Ph3CPF6presumably afforded pentatetraenylidene complex {[Ru]=C=C=C=C=C(C3H5)2}[PF6] (10), which was not isolated. Additions of various alcohols in a solution of 10 generated a number of disubstituted allenylidene complexes {[Ru]=C=C=C(OR)-C=C(C3H5)2}[PF6] (11). Treatment of 11 with K2CO3afforded the acetylide complex 12 bearing a carbonyl group, characterized by single X-ray diffraction analysis. Addition of a primary amine to 10 caused cleavage of the farthermost C=C bond and several allenylidene complexes {[Ru]=C=C=C(Me)(NHR)}[PF6] (18) were isolated.
Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan.
Shih-Hung
SH
Tsai
Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan.
Ying-Chih
http://orcid.org/0000-0002-5887-0880
YC
Lin
Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan.
Yi-Hung
YH
Liu
acetylides; allenylidenes; bond cleavage; pentatetraenylidenes; ruthenium