Enantioselective Alkenylation of Aldimines Catalyzed by a Rhodium–Diene Complex
作者:Zhe Cui、Ya-Jing Chen、Wen-Yun Gao、Chen-Guo Feng、Guo-Qiang Lin
DOI:10.1021/ol5000154
日期:2014.2.7
An efficient rhodium-catalyzed asymmetric addition reaction of potassiumalkenyltrifluoroborates to N-nosylaldimines has been developed. Under optimal conditions, the reactions proceeded with good to excellent yields and excellent enantioselectivities (97 → 99% ee). The utility of this method is demonstrated by the formal synthesis of (−)-aurantioclavine.
作者:Sobia Tabassum、Oksana Sereda、Peddiahgari Vasu Govardhana Reddy、René Wilhelm
DOI:10.1039/b908899g
日期:——
KHMDS and KOtBu are well established as strong, hindered, non-nucleophilic Brønsted bases. However, in the present work these bases are applied as highly active Lewis base catalysts for the formal [2+2] cycloaddition of ketenes with aldehydes and imines.
Hydroxyproline-Derived Pseudoenantiomeric [2.2.1] Bicyclic Phosphines: Asymmetric Synthesis of (+)- and (−)-Pyrrolines
作者:Christopher E. Henry、Qihai Xu、Yi Chiao Fan、Tioga J. Martin、Lee Belding、Travis Dudding、Ohyun Kwon
DOI:10.1021/ja505592h
日期:2014.8.27
We have prepared two new diastereoisomeric 2-aza-5-phosphabicyclo[2.2.1]heptanes from naturally occurring trans-4-hydroxy-l-proline in six chemical operations. These syntheses are concise and highly efficient, with straightforward purification. When we used these chiral phosphines as catalysts for reactions of γ-substituted allenoates with imines, we obtained enantiomerically enriched pyrrolines in
Enantiopure imidazolinium-dithiocarboxylates as highly selective novel organocatalysts
作者:Oksana Sereda、Amélie Blanrue、René Wilhelm
DOI:10.1039/b817991c
日期:——
Asymmetric imidazolinium-dithiocarboxylates have been found for the first time to be highly selective catalysts; in the present case, the novel organocatalysts were able to catalyze the Staudinger reaction in up to 96% ee and 99% yield.
首次发现不对称咪唑啉鎓-二硫代羧酸盐是高选择性催化剂;在本例中,新型有机催化剂能够以高达 96% ee 和 99% 的产率催化施陶丁格反应。