对映体富集的α-羟基酰胺和β-氨基醇的合成已通过用氢硅烷将α-酮酰胺对映选择性还原而完成。通过使用(EtO)3 SiH作为还原剂,在手性Cu II /(S)-DTBM-SEGPHOS催化剂存在下还原了一系列α-酮酰胺,得到了具有出色对映选择性的相应光学活性α-羟基酰胺。此外,使用相同的手性铜催化剂,然后在(EtO)3 SiH存在下,用四正丁基氟化铵(TBAF)催化剂,一锅完全还原了α-酮酰胺的酮基和酰胺基。相应的手性β-氨基醇衍生物。
A number of opticallyactive amino alcohols were synthesized by direct asymmetric transfer hydrogenation of the corresponding amino ketones with good-to-high enantiomeric excesses (up to 95%) and excellent yields (up to 93% ). When the range of substrates was broadened to include α-sulfonamido ketones or α-keto sulfones, the corresponding products were obtained with 100% enantiomeric excesses. The
Acid-Assisted Ru-Catalyzed Enantioselective Amination of 1,2-Diols through Borrowing Hydrogen
作者:Li-Cheng Yang、Ya-Nong Wang、Yao Zhang、Yu Zhao
DOI:10.1021/acscatal.6b02959
日期:2017.1.6
Here, we present a highly enantioselectivesynthesis of 1,2-amino alcoholsfrom readily available racemic 1,2-diols through a borrowinghydrogen process. An intriguing acid effect was discovered for this Ru-catalyzed amination reaction, which led to a significant improvement of the stereoselectivity of the process. Preliminary mechanistic studies suggest a scenario of Brønsted acid-assisted dynamic