126752-55-4Relevant academic research and scientific papers
Organic Syntheses via Transition Metal Complexes, 46. - Alkenylcarbene Chromium and Tungsten Complexes; Proton Addition and Activation by Electron-Withdrawing Substituents
Aumann, Rudolf,Hinterding, Peter,Krueger, Carl,Betz, Peter
, p. 1847 - 1852 (2007/10/02)
Alkenylcarbene complexes LnM=C(OEt)-CH=C(R)NMe2 add HBF4 in ether to give novel cationic carbene complexes BF4 (3) by protonation at C-2 of the =C-C=C ligand.The addition of HBF4 to 7 leads to the formation of the cyclic carbene complexes 8.Structures of 3 and 8 are assigned spectroscopically.X-ray data are reported for 8a.Protonation of 1 and 7 results in a strong deshielding of the carbene carbon atoms, which parallels an increase of reactivity at the M=C bonds.An activation of the M=C bond has also been achieved by electron-withdrawing substituents like N-acyl groups.We report on the first synthesis of carbene complexes 13, which are more reactive than β-(aminoalkenyl)carbene complexes 7.
