207388-39-4Relevant academic research and scientific papers
Synthesis of ruthenium vinylidene complexes with dppe ligand and their cyclopropenation reaction
Chang, Chao-Wan,Ting, Pei-Chen,Lin, Ying-Chih,Lee, Gene-Hsiang,Wang, Yu
, p. 417 - 425 (1998)
A number of cationic ruthenium vinylidene complexes [Ru]=C=C(Ph)CH2R+ ([Ru]=(η5-C5H5)(dppe)Ru, dppe=Ph2PCH2CH2PPh2, 5a, R=CN; 5b, R=C6F5; 5c, R=Ph; 5d, R=p-C6H4CN; 5e, R=p-C6H4CF3; 5f, R=1-C10H7; 5g, R=CO2CH3) are prepared from electrophilic addition of organic halides to the acetylide complex [Ru]-CCPh at the boiling point of CHCl3. Complex 5g′, prepared at room temperature, displays similar spectroscopic property as that of 5g but is easily hydrolyzed to give [Ru]COCH2Ph (6). Cyclopropenation of the organic vinylidene moiety of 5a-5f is accomplished in acetone by deprotonation of 5 with n-Bu4NOH yielding the neutral cyclopropenyl complexes (7a, R=CN; 7b, R=C6F5; 7c, R=Ph; 7d, R=p-C6H4CN; 7e, R=p-C6H4CF3; 7f, R=1-10H7). Protonation of 7b-7f regenerates the corresponding vinylidene complexes. In the presence of allyl iodide, opening of the three-membered ring of 7a, followed by a subsequent oxidative coupling reaction, gives a dimeric dicationic product {[Ru]=C=C(Ph)-CHCN}2+2 (9a). In the processes of preparing the starting material Cp(dppe)RuCl for the acethylide complex, two dppe complexes Ru(dppe)2Cl2 (2) and [Cp(dppe)RuCl]2 (3) are isolated. Molecular structures of complexes 2, 3, 6, and 7b have been confirmed by X-ray diffraction analysis.
