Development of a Chiral Bis(guanidino)iminophosphorane as an Uncharged Organosuperbase for the Enantioselective Amination of Ketones
摘要:
Chiral bis(guanidino)iminophosphoranes were designed and synthesized as chiral uncharged organosuperbase catalysts that facilitate activation of lessacidic pro-nucleophiles. The newly developed bis(guanidino)iminophosphoranes, which possess the highest basicity among chiral organocatalysts reported to date, were proven to be a superb class of chiral organosuperbases by reaction of azodicarboxylates with 2-alkyltetralones and their analogues as the less acidic pro-nucleophiles.
Development of a Chiral Bis(guanidino)iminophosphorane as an Uncharged Organosuperbase for the Enantioselective Amination of Ketones
作者:Tadahiro Takeda、Masahiro Terada
DOI:10.1021/ja408296h
日期:2013.10.16
Chiral bis(guanidino)iminophosphoranes were designed and synthesized as chiral uncharged organosuperbase catalysts that facilitate activation of lessacidic pro-nucleophiles. The newly developed bis(guanidino)iminophosphoranes, which possess the highest basicity among chiral organocatalysts reported to date, were proven to be a superb class of chiral organosuperbases by reaction of azodicarboxylates with 2-alkyltetralones and their analogues as the less acidic pro-nucleophiles.
Fluoride Anions in Self-Assembled Chiral Cage for the Enantioselective Protonation of Silyl Enol Ethers
The potential of Song’s chiral oligoethylene glycols (oligoEGs) as catalysts was explored in the enantioselective protonation of trimethylsilyl enolethers in combination with alkali metal fluoride (KF and CsF) and in the presence of a proton source. Highly enantioselective protonations of various silylenolethers of α-substituted tetralones were achieved, producing chiral α-substituted tetralones