Reactions of Ruthenium Vinylidene Complexes with Terminal Alkyne Containing Pyrrole Carbaldeyhde
Date Issued
2011
Date
2011
Author(s)
Chia, Pi-Yeh
Abstract
Treatment of the N-propargyl pyrrole 1 with [Ru]-Cl ([Ru] = Cp(PPh3)2Ru) in the presence of KPF6 in CH2Cl2 afforded the vinylidene complex 2. A solution of 2 in CH2Cl2 was reacted with an aliquot of NH3 solution in methanol at room temperature to yield the Fischer-type aminocarbene ruthenium(II) complex 5. The reaction of complex 2 with primary amine in CH2Cl2, however, yielded the ruthenium(II) carbene complex 8. Deprotonation of 2 with base afforded a neutral acetylide complex 3. The reaction of complex 3 with haloacetates in the presence of KPF6 then afforded the disubstituted vinylidene complexes 4a and 4b. In the deprotonation reactions of these disubstituted vinylidene complexes containing ester groups, the furyl complexes 6a and 6b were obtained, respectively. For the furyl complex 6a containing an O-benzyl group, a subsequent 1,3-migration of the benzyl group is observed to yield the lactone product 7a. The reaction of [Ru]-Cl with compound 9 and NH4PF6 in CH2Cl2 for 1 day yielded the vinylidene complex 10. When the solvent of the reaction was changed from CH2Cl2 to methanol, the reaction gave the cyclization product 11, possibly via the intermediate complex 10. Reaction of iminenyne 12 with [Ru]-Cl and NH4PF6 in CH2Cl2 for 1 day yielded the ruthenium complex 13 containing cationic imine group. Complexes 3, 4a and 13 are fully characterized by X-ray diffraction analysis.
Subjects
ruthenium
enyne
pyrrolecarbaldehyde.
Type
thesis
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