N-heterocyclic carbene complexes of Rh(I) and electronic effects on catalysts for 1,2-addition of phenylboronic acid to aldehydes
作者:Hayati Türkmen、Bekir Çetinkaya
DOI:10.1002/aoc.1746
日期:2011.3
The relative σ‐donor/π‐acceptor strength of the NHC ligands was determined by means of IR spectroscopy of 5. The ability of NHCs in 4 to enchance activity was explored in the 1,2‐addition of phenylboronic acid to aldehydes. A good correlation was observed between catalytic activity and the electron‐donating power of the NHC ligands. Copyright © 2010 John Wiley & Sons, Ltd.
1,3-二芳基取代的咪唑啉鎓盐(NHC-H)Cl,3在咪唑烷环的4,5-位上含有氢或烷基,是铑(I)络合物[RhCl(NHC)COD]的前体,4,将其转化为顺式-[RhCl(NHC)(CO)2 ]配合物,5。所有制备的化合物均通过元素分析,1 H NMR和13 C NMR表征。通过5的红外光谱确定NHC配体的相对σ供体/π受体强度。在苯基硼酸1,2加成醛中探索了NHC在4中的增附活性。在NHC配体的催化活性和给电子能力之间观察到良好的相关性。版权所有©2010 John Wiley&Sons,Ltd.