Conversion of Propargylic Alcohols to β-Oxo Esters Catalyzed by Novel Ruthenium-Phosphoramidite Complexes
作者:Stephen Costin、Nigam P. Rath、Eike B. Bauer
DOI:10.1002/adsc.200800355
日期:2008.10.6
from propargylic alcohols and carboxylic acids. Standard conditions involve cyclohexane solvent, propargylic alcohol (1.0 equiv.), carboxylic acid (1.0 equiv.), ruthenium catalyst (1.5 mol%), and 90 °C for 5–18 h. Isolated yields of the β-oxo esters range from 87 to 16% and show broad substrate generality. The reaction proceeds without racemization if a chiral propargylic alcohol is employed. The method
合成了一系列钌的半三明治亚磷酰胺络合物,并将其用作由羧酸和炔丙醇原子经济形成β-氧代酯的催化剂。亚磷酰胺(R)-BINOL-PNR 2(R = Me,1a ; i- Pr,1b ;苄基,1c)和(rac)-6,6'-dibromo-BINOL-PNMe 2(1d)与亚氨基的反应二聚对-cymene-二氯化钌络合物[RuCl 2(p- cymene)] 2给出了络合物[RuCl 2(p- cymene)(L)](L =1a,7a ; 1b,7b ; 1c,7c ; 1d,7d),产率96-66%。因此,(R)-BINOL(8H)-PNMe 2(2a)和(R)-BINOL(8H)-PN(苄基)2(2b)与[RuCl 2(对-cymene)] 2反应得到配合物。 [RuCl 2(p- cymene)(L)](L = 2a,8a ; 2b,8b),产率分别为82%和86%。在相似的反应中,用[RuCl