Selective 1,3-cycloboronation of enantiopure 1,1,4,4-tetrasubstituted butanetetraols: versatile preparation, structural characterization, and properties of chiral cyclic boron-containing bifunctional Lewis acids
摘要:
The selective cycloboronation of enantiopure 1,1,4,4-tetrasubstituted butanetetraols was investigated, and a general preparation of chiral cyclic boron-containing bifunctional Lewis acids was discovered. Compounds (2R,3R)- or (2S,3S)-1,1,4,4-tetrasubstituted butanetetraols were reacted with ArB(OH)(2) at reflux in toluene, or THF, or under solvent-free condition to furnish tricoordinated, chiral bicyclo[4.4.0]diboronic esters in high yield via selective 1,3-cycloboronation. Structural characterization and properties of the novel chiral boron compounds are also reported. (C) 2009 Elsevier Ltd. All rights reserved.
Selective 1,3-cycloboronation of enantiopure 1,1,4,4-tetrasubstituted butanetetraols: versatile preparation, structural characterization, and properties of chiral cyclic boron-containing bifunctional Lewis acids
摘要:
The selective cycloboronation of enantiopure 1,1,4,4-tetrasubstituted butanetetraols was investigated, and a general preparation of chiral cyclic boron-containing bifunctional Lewis acids was discovered. Compounds (2R,3R)- or (2S,3S)-1,1,4,4-tetrasubstituted butanetetraols were reacted with ArB(OH)(2) at reflux in toluene, or THF, or under solvent-free condition to furnish tricoordinated, chiral bicyclo[4.4.0]diboronic esters in high yield via selective 1,3-cycloboronation. Structural characterization and properties of the novel chiral boron compounds are also reported. (C) 2009 Elsevier Ltd. All rights reserved.
A Convenient Approach to<i>C</i><sub>2</sub>-Chiral 1,1,4,4-Tetrasubstituted Butanetetraols: Direct Alkylation or Arylation of Enantiomerically Pure Diethyl Tartrates
作者:Zixing Shan、Xiaoyun Hu、Yan Zhou、Xitian Peng、Zhen Li
DOI:10.1002/hlca.200900274
日期:2010.3
C2‐Chiral 1,1,4,4‐tetraaryl‐ or 1,1,4,4‐tetraalkyl‐substituted butanetetraols have been conveniently synthesized via arylation or alkylation of unprotected diethyl (2R,3R)‐ and (2S,3S)‐tartrates with Grignard reagent. The chiral 1,1,4,4‐tetrasubstituted butanetetraols were characterized by IR, 1H‐ and 13C‐NMR, as well as LC/MS.