A pi-basic rhenium center that effects cyclohexene isomerization to a beta-agostic carbene ligand |
| |
Authors: | Ozerov Oleg V Watson Lori A Pink Maren Caulton Kenneth G |
| |
Institution: | Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA. |
| |
Abstract: | The molecule (PNPR)Re(H)4 (PNPR = (R2PCH2SiMe2)2N, R = iPr or cyclohexyl) reacts at 20 degrees C with 2 mol of cyclohexene to form equimolar cyclohexane and (PNPR)Re(H)2=C(CH2)5]. This product is characterized by 1H, 13C, and 31P NMR and by X-ray diffraction as having one CH2 hydrogen (from a carbon located beta to Re) donating to the metal ("agostic CH"). This interaction occurs in preference to PNPR amide nitrogen pi-donation. DFT calculations confirm this agostic interaction, and show that the (PNPR)Re(H)2 fragment indeed reverses the greater stability of free olefin vs free carbene. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|