Chiral Ruthenium PNNP Complexes of Non-Enolized 1,3-Dicarbonyl Compounds: Acidity and Involvement in Asymmetric Michael Addition
作者:Martin Althaus、Cristina Bonaccorsi、Antonio Mezzetti、Francesco Santoro
DOI:10.1021/om060389k
日期:2006.6.1
The chiral complexes [Ru(2)(PNNP)]2+ (4a) and [Ru(3)(PNNP)]2+ (4b), containing the non-enolized 1,3-dicarbonyl compounds 2-((tert-butoxy)carbonyl)cyclopentanone (2) or α-acetyl-N-benzyl-δ-valerolactam (3), were deprotonated to the enolato complexes 5a,b. Complex 4a has a pseudo-aqueous pKa value of 4.6 ± 0.5 (with pKa(Ph3PH+) = 2.7 as reference) and catalyzes the 1,4-addition of 2 to methyl vinyl ketone
[Ru(2)(PNNP)] 2+(4a)和[Ru(3(PNNP)] 2+(4b)的手性络合物,包含未烯化的1,3-二羰基化合物2-((叔-丁氧基)羰基)环戊酮(2)或α-乙酰基-N-苄基-δ-戊内酰胺(3)被去质子化为Enolato络合物5a,b。配合物4a的拟水p K a值为4.6±0.5(p K a(Ph 3 PH +)= 2.7作为参考),并以高达79%的ee催化2与甲基乙烯基酮的1,4-加成反应。