Catalytic Enantioselective Addition of Cyclic β-Keto Esters with Activated Olefins and N-Boc Imines Using Chiral <i>C</i><sub>2</sub>-Symmetric Cationic Pd<sup>2+</sup> N-Heterocyclic Carbene (NHC) Diaqua Complexes
作者:Zhen Liu、Min Shi
DOI:10.1021/om100331z
日期:2010.6.28
The asymmetric addition of cyclic β-keto esters to activated olefins and N-Boc imines was realized by using chiral cationic C2-symmetric N-heterocyclic carbene (NHC) Pd2+ diaqua complexes 1a,b as the catalysts, producing the corresponding adducts in moderate to high yields (up to 95%) and with good to high enantioselectivities (up to 96% ee). Nevertheless, the most significant observation is that when