C−H Oxidative Addition to a (PNP)Ir Center and Ligand-Induced Reversal of Benzyl/Aryl Selectivity
摘要:
The (PNP)Ir fragment displays a thermodynamic preference for the oxidative addition of aromatic vs benzylic C-H bonds. However, in the case of the mesitylene activation products, the benzylic isomer is kinetically accessible and can be trapped by an external donor ligand. The preference for the benzylic isomer in the six-coordinate Ir(III) adduct of mesitylene activation is ascribed to steric factors.
DOI:
10.1021/om701110y
作为产物:
描述:
双[2-(二异丙基膦)-4-甲基苯基]胺 、 bis(1,5-cyclooctadiene)diiridium(I) dichloride 以
not given 为溶剂,
以99%的产率得到(PNP)IrHCl
参考文献:
名称:
Facile Oxidative Addition of N−C and N−H Bonds to Monovalent Rhodium and Iridium
摘要:
An investigation of room-temperature oxidative addition of N-C and N-H bonds to RhI and IrI in solution and in the solid state is presented. The rigid, product-adapted framework of the pincer bis(ortho-phosphinoaryl)amine (PNP) ligand may contribute to the ease of the N-C and N-H cleavage. The migration of Me from N of the coordinated amine moiety to Rh proceeds with near-zero entropy of activation in solution. In the solid state, this transformation is a crystal-to-crystal reaction, transforming only one of the two independent molecules of (PN(Me)P)RhCl into (PNP)Rh(Me)Cl.
Halobenzenes and Ir(I): Kinetic C−H Oxidative Addition and Thermodynamic C−Hal Oxidative Addition
作者:Lei Fan、Sean Parkin、Oleg V. Ozerov
DOI:10.1021/ja0557637
日期:2005.12.1
A (PNP)Ir fragment undergoes facile, room-temperature oxidative addition of C-H bonds in arenes and haloarenes in preference to aromatic carbon-halogen bonds. This preference, however, is determined to be kinetic in nature. Oxidative addition of C-Cl and C-Br is preferred thermodynamically. The products of the C-Cl or C-Br oxidative addition are separated from the C-H oxidative addition products by a high activation barrier and are only accessible at >100 degrees C. Of the C-H oxidative addition products of chlorobenzene, the isomer with the o-ClC6H4 ligand has the lowest energy.