A chiral N-linked C2-symmetric bidentate phosphoramidite (N-Me-BIPAM) was newly developed for the rhodium-catalyzed enantioselective addition of arylboronicacids to N-sulfonylimines. This ligand achieved high enantioselectivities in a range of 84–99% ee in additions of arylboronicacids to N-tosyl- and N-nosylarylaldimines.
The potential of β‐alkoxy α‐keto amides as pronucleophiles in the enantioselective Mannich type reaction with p‐nosyl imines is presented. The proper combination of β‐alkoxy α‐keto amides and a squaramide‐based Brønsted basecatalyst produced highly enantioenriched Mannich adducts, which may be transformed into functionalized amino diols.
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.
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