Synthesis and separation of diastereomeric imino alcohol derivatives of chiral phthalides: a method for assignment of phthalide absolute configurations
A New Asymmetric Synthesis of (<i>R</i>)- and (<i>S</i>)-3-Arylphthalides: Extremely High Diastereoselective Reaction of Arylcarbaldehydes with Chiral [2-(1,3-Oxazolidin-2-yl)phenyl]titanium Ate Complexes
Chiral [2-(1,3-oxazolidin-2-yl)phenyl]titanium ate complexes are prepared from the corresponding lithium complexes, and the extremely high diastereoselective reaction of arylcarbaldehydes with the chiral titanium ate complexes is performed. Then, optically pure (R)- and (S)-3-arylphthalides are synthesized in favorable yields and the chiral auxiliary reagents are recovered with no less of the optical purity.
Catalytic asymmetric synthesis of 3-aryl phthalides enabled by arylation–lactonization of 2-formylbenzoates
作者:Andressa M. M. Carlos、Rafael Stieler、Diogo S. Lüdtke
DOI:10.1039/c8ob02872a
日期:——
The catalytic asymmetric synthesis of 3-aryl phthalides is reported through a sequential asymmetric arylation–lactonization reaction. The reaction is enabled by a boron–zinc exchange to generate reactive arylating agents, which react with 2-formylbenzoates in the presence of a chiral amino naphthol ligand. The enantiodetermining step is the arylation of the aldehyde, which then undergoes a lactonization
Catalytic asymmetric 1,2-Addition/Lactonization tandem reactions for the syntheses of chiral 3-Substituted phthalides using organozinc reagents
作者:Huayin Huang、Yabai Wang、Hua Zong、Ling Song
DOI:10.1002/aoc.4643
日期:2019.1
Using chiral phosphoramide ligand 2d‐Zn (II) complex derived from (1R,2R)‐1,2‐diphenylethylenediamine as the catalyst, we have developed efficient catalytic asymmetric 1,2‐addition/lactonization tandem reactions of diverse organozinc reagents with varied methyl 2‐formylbenzoates for the construction of optically enriched 3‐aryl or alkyl substituted phthalides, which are significant building blocks