224293-75-8Relevant academic research and scientific papers
Allenylidene Ligand of [Ru(η5-C5H5)(C=C=CPh 2)(CO)(PPri3)]BF4 as Entry to Novel Unsaturated η1-Carbon Ligands Containing Azetidine and Hexahydroquinoline Skeletons
Esteruelas, Miguel A.,Gómez, Angel V.,López, Ana M.,O?ate, Enrique,Ruiz, Natividad
, p. 1606 - 1613 (2008/10/08)
The allenylidene complex [Ru(η5-C5H5)(C=C=CPh 2)(CO)(PPri3)]BF4 (1) reacts with dicyclohexylcarbodiimide to give the iminiumazetidinylidenemethyl complex [Ru(η5-C5H5){CH= CCPh2N(Cy)=C=N=C(CH2)4CH 2}(CO)(PPri3)]BF4 (2), as a 4:1 mixture of isomers Z (2a) and E (2b). The structure of 2a was determined by an X-ray investigation, revealing a Ru-C distance of 2.070(4) A?. Treatment of the isomeric mixture of 2 with sodium methoxide in tetrahydrofuran at room temperature affords the iminoazetidinylidenemethyl complex Ru(η5-C5H5){(Z)-CH=CCPh 2N(Cy)C=NC=CH(CH2)3CH2}(CO)(PPr i3) (6), which reacts with HBF4·OEt2 to give [Ru(η5-C5H5){(Z)-CH=CCPh 2N(Cy)C=N(H)C=CH(CH2)3CH 2}(CO)(PPri3)]-BF4 (7), as a result of the protonation of the exocyclic nitrogen atom of the unsaturated η1-carbon ligand of 6. In the solid state and in solution at low temperature, complex 7 is stable. However, in solution at room temperature, complex 7 evolves into [Ru(η5-C5H5){(Z)-CH=CCPh 2C(CH2)4CN(H)=CNHCy}(CO)(PPri 3)]BF4 (8), which reacts with sodium methoxide in tetrahydrofuran at room temperature to give the hexahydroquinolinylidenemethyl complex Ru(η5-C6H5){(Z)-CH=CCPh 2C(CH2)4CN=CNHCy}(CO)(PPri 3) (9), as a result of the deprotonation of the endocyclic nitrogen atom of 8. The structure of 9 was also determined by an X-ray investigation, revealing, in this case, a Ru-C distance of 2.113(4) A?. The formation of the azetidine and hexahydroquinoline skeletons of the ligands of these compounds is discussed.
