A Chiral Electrophilic Selenium Catalyst for Highly Enantioselective Oxidative Cyclization
作者:Yu Kawamata、Takuya Hashimoto、Keiji Maruoka
DOI:10.1021/jacs.6b01462
日期:2016.4.27
Chiral electrophilic selenium catalysts have been applied to catalytic asymmetric transformations of alkenes over the past two decades. However, highlyenantioselective reactions with a broad substrate scope have not yet been developed. We report the first successful example of this reaction employing a catalyst based on a rigid indanol scaffold, which can be easily synthesized from a commercially
Stereoselective Ring-Opening of <i>gem</i>
-Difluorocyclopropanes: An Entry to Stereo-defined (<i>E</i>
,<i>E</i>
)- and (<i>E</i>
,<i>Z</i>
)-Conjugated Fluorodienes
The ring‐opening of gem‐difluorocyclopropyl acetaldehydes producing selectively (E,E)‐ and (E,Z)‐conjugated fluorodienals is described. Two stereo‐divergent methods are presented to access both stereoisomers from a common precursor, in high yield and selectivity. The mechanistic aspect of these transformations is discussed.