Axially Chiral Macrocyclic E-Alkene Bearing Bisazole Component Formed by Sequential C–H Homocoupling and Ring-Closing Metathesis
摘要:
Clipping by ring-closing metathesis freezes rotation of a C-C bond to result in forming axial chirality. Treatment of bisbenzimidazole bearing an N-(3-butenyl) substituent with a Grubbs' catalyst undergoes ring-closing metathesis, in which the stereochemistry of the thus formed olefin was exclusively E-form. Analysis by HPLC with a chiral stationary column confirmed clear baseline separation of each enantiomer.
The absolute stereochemistry of compounds with axial and planar chirality is successfully determined by the crystalline sponge method without crystallization or derivatization of the compounds. This method is applied to...
Winding vine‐shaped molecular asymmetry is induced by enantioselective ring‐closingmetathesis with a chiral molybdenum catalyst. The reaction proceeds under mild conditions through an E‐selective ring‐closingmetathesis leading to macrocyclic bisazoles with enantioselectivities of up to 96 % ee.
Axially Chiral Macrocyclic <i>E</i>-Alkene Bearing Bisazole Component Formed by Sequential C–H Homocoupling and Ring-Closing Metathesis
作者:Shotaro Nishio、Takashi Somete、Atsushi Sugie、Tohru Kobayashi、Tsuyoshi Yaita、Atsunori Mori
DOI:10.1021/ol300755y
日期:2012.5.18
Clipping by ring-closing metathesis freezes rotation of a C-C bond to result in forming axial chirality. Treatment of bisbenzimidazole bearing an N-(3-butenyl) substituent with a Grubbs' catalyst undergoes ring-closing metathesis, in which the stereochemistry of the thus formed olefin was exclusively E-form. Analysis by HPLC with a chiral stationary column confirmed clear baseline separation of each enantiomer.