Application of a Chiral Scaffolding Ligand in Catalytic Enantioselective Hydroformylation
作者:Amanda D. Worthy、Candice L. Joe、Thomas E. Lightburn、Kian L. Tan
DOI:10.1021/ja107433h
日期:2010.10.27
The synthesis of β-amino-aldehydes has been achieved throughenantioselective hydroformylation of PMP-protected allylic amines. The reaction is accomplished by using a scalemic scaffolding ligand that covalently and reversibly binds to the substrate. These ligands behave like chiral auxiliaries because they are covalently attached to the substrate during hydroformylation; however, similar to traditional
β-氨基醛的合成是通过 PMP 保护的烯丙胺的对映选择性加氢甲酰化来实现的。该反应是通过使用与底物共价可逆结合的鳞片支架配体来完成的。这些配体的行为类似于手性助剂,因为它们在加氢甲酰化过程中共价连接到底物上;然而,与传统的不对称配体类似,它们可以以催化量使用。二取代烯烃的直接加氢甲酰化在温和条件(35 °C 和 50 psi CO/H(2))下进行,Z-烯烃具有优异的对映选择性(高达 93% ee)。
CONCISE BETA2-AMINO ACID SYNTHESIS VIA ORGANOCATALYTIC AMINOMETHYLATION
申请人:CHI Yonggui
公开号:US20080058548A1
公开(公告)日:2008-03-06
The present invention provides a method for the synthesis of β
2
-amino acids. The method also provides methods yielding α-substituted β-amino aldehydes and β-substituted γ-amino alcohols. The present method according to this invention allows for increased yield and easier purification using minimal chromatography or crystallization. The methods described herein are based on an aldehyde aminomethylation which involves a Mannich reaction between an aldehyde and a formaldehyde-derived N,O-acetal (iminium precursor) and a catalyst, such as, for example, L-proline or a pyrrolidine. The invention allows for large scale, commercial preparation of β
2
-amino acids.