Nickel‐Catalyzed Asymmetric Hydrogenation of 2‐Amidoacrylates
作者:Yawen Hu、Jianzhong Chen、Bowen Li、Zhenfeng Zhang、Ilya D. Gridnev、Wanbin Zhang
DOI:10.1002/anie.201916534
日期:2020.3.23
chiral bisphosphine ligand, was found to be an efficientcatalyst for the asymmetric hydrogenation of 2-amidoacrylates, affording the chiral α-aminoacid esters in quantitative yields and excellent enantioselectivity (up to 96 % ee). The active catalyst component was studied by NMR and HRMS, which helped us to realize high catalytic efficiency on a gram scale with a low catalyst loading (S/C=2000).
发现富含地球的镍与合适的手性双膦配体配合使用,是2-酰胺基丙烯酸酯不对称氢化的有效催化剂,以定量收率和优异的对映选择性(高达96%ee)提供了手性α-氨基酸酯。通过NMR和HRMS对活性催化剂组分进行了研究,这有助于我们以克级实现高催化效率且催化剂负载量低(S / C = 2000)。氢化产物可以简单地转化为手性α-氨基酸,β-氨基醇及其生物活性衍生物。此外,使用氘标记实验和计算计算研究了催化机理。
Organocatalytic asymmetric double Michael reaction of Nazarov reagents with alkylidene azlactones for the construction of spiro-fused cyclohexanone/5-oxazolone system
A bifunctional thiourea-tertiary amine-catalyzed enantioselective double Michael reaction of Nazarov reagents and alkylidene azlactones was realized. Using this protocol, a series of optically active spiro-fused cyclohexanone/5-oxazolone derivatives, bearing three consecutive chiral centers including one Spiro quaternary chiral center, were obtained in good yields with good stereoselectivities (up to 93% yield, 99:1 dr, and 91% ee). The synthetic utility of the products for the formation of chiral cyclic quaternary amino-acid derivatives was also demonstrated. (C) 2014 Elsevier Ltd. All rights reserved.