148185-07-3Relevant academic research and scientific papers
Synthesis and crystal structure of CC(O)CH3>3>. Its role in the cyclotrimerization of 1-phenylbut-1-yn-3-one to 1,3,5-triphenyltris(carboxymethyl)benzene
Gervasio, Giuliana,Sappa, Enrico,Marko, Laszlo
, p. 203 - 209 (1993)
The reaction of with 1-phenylbut-1-yn-3-one in refluxing toluene yields CC(O)CH3>>, the symmetrical trimer 3, which were characterized by spectroscopic techniques, and the title complex, the structure of which has been elucidated by X-ray analysis.The crystals are monoclinic P21/c with a = 10.640(2), b = 17.741(4), c = 17.845(4) Angstroem, β = 90.50(3) deg, Z = 4.The molecule has a Co-Co bond and the 3 chain links the cobalt atoms in a flyover arrangement.To our knowledge, this is the first example of stepwise formation of a symmetrical benzene from an asymmetrical, internal alkyne via this type of intermediate.
Radical reactions of the cobalt-complexed propargyl acetals: Inter- and intramolecular variants
Melikyan, Gagik G.,Voorhees, Erin,Sepanian, Ruth
, p. 69 - 83 (2014/02/14)
Propargyl acetals are used as a new type of substrate in cobaltocene-induced radical reactions stereodirected by a π-bonded Co 2(CO)6 metal core. The experimental protocol involves treatment of the cobalt-complexed acetals with triflic anhydride, an in situ generation of ionic propargyl triflates, and a single-electron, low-temperature reduction of α-alkoxy-stabilized, Co2(CO)6-complexed propargyl cations. Inter- and intramolecular reactions provide a facile access to polyfunctional, topologically diverse 3,4-dialkoxy-1,5-alkadiynes and 3,4-dialkoxy-1,5-cyclodecadiynes with a predominant formation of the respective d,l-diastereomers (73-100% d,l). The stereo- and chemoselectivities are found to be dependent upon the (1) bulkiness of the gamma substituent (1,3-steric induction; d,l- 73-100%), (2) presence of a phosphorus ligand altering the π-bonded metal core (axial ligand induction; d,l- 91-97%), and (3) steric hindrance created by an alpha alkoxy group (1,1-steric induction; d,l- 83-92%).
