Untitled

Reactions of Ruthenium Complexes Containing Pentatetraenylidene Ligand

“…The 31 P NMR spectrum of 14 displays a doublet resonance at δ =49.6 ppm assigned to two PPh 3 ligands bonded to the ruthenium metal and a triplet resonance at δ =17.18 ppm assigned to the phosphonium group at Cγ of the acetylide ligand. In the 13 C NMR spectrum of 14 , four doublet resonances at δ =216.6, 119.2, 118.1, and 98.8 ppm with J CP =12.7, 87.2, 15.2 and 9.1 Hz are assigned to Cδ,, Cγ, Cϵ, and Cβ, respectively, according to the 2D 1 H‐ 13 C HSQC and HMBC NMR spectra.…”

3,4-Dibromo-2,2,5,5-tetraphenyl-2,5-dihydrofuran

“…The title compound was obtained as an unexpected product in a bromination reaction of 1,1-diphenylprop-2-yne-1-ol in order to obtain 1,1-diphenyl-3-bromo-2-propyne-1-ol. Performance of this transformation using potassium hydroxide dissolved in water, bromine and 1,1-diphenyl-2-propyne-1-ol (Maraval et al, 2008) added as a solution in n-pentane at 273 K following conditions of a described procedure (Saalfrank et al, 1996) yielded the intended product. However, when applying the same synthesis but heating the reaction mixture to reflux for 12 h instead of stirring for 60 h at room temperature, the modified reaction condition surprisingly led to the formation of the title compound as the main product.…”

Organotin Reagents in Cross‐Coupling Reactions

“…Saalfrank et al [182] allowed stannylalkynes or bis(trimethylstannyl)alkyne to react with bromoallenes to afford conjugated alkynylallenes or diastereomeric ynediallenes. Diederich et al [183] synthesized a novel light-driven fully reversible molecular switch by a cross-coupling between a stannylated tetraethynylethene and a 3-iodo-1,1 -binaphthyl derivative (Scheme 6.43).…”