A Novel Bifunctional Sulfonamide Primary Amine-Catalyzed Enantioselective Conjugate Addition of Ketones to Nitroolefins
作者:Fei Xue、Shilei Zhang、Wenhu Duan、Wei Wang
DOI:10.1002/adsc.200800445
日期:2008.10.6
The enantioselectiveconjugateaddition of a variety of ketones to nitroolefins has been developed. The process is efficiently catalyzed by a novelbifunctionalsulfonamideprimary amine in good yields and with good levels of enantioselectivity.
Highly enantioselective Michael addition of acetone to nitroolefins catalyzed by chiral bifunctional primary amine-thiourea catalysts with acetic acid
作者:Qing Gu、Xing-Tao Guo、Xin-Yan Wu
DOI:10.1016/j.tet.2009.04.087
日期:2009.7
Highlyenantioselective Michael reaction of acetone with a variety of nitroolefins catalyzed by N-[(1R,2R)-2-aminocyclohexyl]-N′-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)-thiourea (1b) together with acetic acid is described. The Michael addition products were obtained in high yields (76–94%) and up to 96% ee.
N -[(1 R,2 R)-2-氨基环己基] -N '-(2,3,4,6-四-O-乙酰基-β- d催化的丙酮与多种硝基烯烃的高度对映选择性迈克尔反应描述了-吡喃葡萄糖基)-硫脲(1b)与乙酸。迈克尔加成产物的收率很高(76-94%),ee最高可达96%。
Highly Enantioselective Synthesis of γ-Nitro Heteroaromatic Ketones in a Doubly Stereocontrolled Manner Catalyzed by Bifunctional Thiourea Catalysts Based on Dehydroabietic Amine: A Doubly Stereocontrolled Approach to Pyrrolidine Carboxylic Acids
作者:Xianxing Jiang、Yifu Zhang、Albert S. C. Chan、Rui Wang
DOI:10.1021/ol8025268
日期:2009.1.1
class of dehydroabietic amine-substituted primary amine-thiourea bifunctional catalysts were designed and synthesized. The doubly stereocontrolled organocatalytic conjugateaddition of a variety of heterocycles-bearing ketones to nitroalkenes was investigated for the first time, affording (S)- or (R)-γ-nitro heteroaromatic ketones with excellent enantioselectivities (up to ee >99%). Furthermore, the nearly
Highly Efficient Amine Organocatalysts Based on Bispidine for the Asymmetric Michael Addition of Ketones to Nitroolefins
作者:Zhigang Yang、Jie Liu、Xiaohua Liu、Zhen Wang、Xiaoming Feng、Zhishan Su、Changwei Hu
DOI:10.1002/adsc.200800341
日期:2008.9.5
highly diastereoselective and enantioselective Michael addition of cyclohexanone, acetone and other ketones to nitroolefins was developed by the use of an amine organocatalyst based on bispidine. Additionally, a theoretical study of transition structures revealed that this bispidine-based primary-secondary amine catalyst could serve through an enamine intermediate and H-bond interaction, which was
Highly Enantioselective Michael Addition of Nitroalkanes to Enones and Its Application in Syntheses of (R)-Baclofen and (R)-Phenibut
作者:Feng Sha、Xin-Yan Wu、Xing-Tao Guo、Jie Shen
DOI:10.1055/s-0034-1380203
日期:——
enantioselectivities. A highly enantioselective Michael addition of nitroalkanes to α,β-unsaturated ketones was developed. In the presence of a chiral primary amine–thiourea catalyst based on dehydroabietic amine, γ-nitro ketones were obtained with excellent enantioselectivities (up to 99% ee) and in up to 96% yield. This protocol was successfully applied in asymmetric syntheses of (R)-baclofen and (R)-phenibut