Construction of Chiral Quaternary Carbon through Morita-Baylis-Hillman Reaction: An Enantioselective Approach to 3-Substituted 3-Hydroxyoxindole Derivatives
作者:Xiao-Yang Guan、Yin Wei、Min Shi
DOI:10.1002/chem.201002240
日期:2010.12.10
A new enantioselectiveapproach to obtain a tetrasubstituted chiral center at the C3 position of oxindoles via a catalytic asymmetric Morita–Baylis–Hillmanreaction has been demonstrated. This reaction provides 3‐substituted 3‐hydroxy‐2‐oxindoles in good to excellent yields and ee values, which could be facilely transformed to pharmaceutically more interesting compounds.
Carbene‐Catalyzed Enantioselective Aromatic N‐Nucleophilic Addition of Heteroarenes to Ketones
作者:Yonggui Liu、Guoyong Luo、Xing Yang、Shichun Jiang、Wei Xue、Yonggui Robin Chi、Zhichao Jin
DOI:10.1002/anie.201912160
日期:2020.1.2
and optical purities. Our reaction involves the formation of an unprecedented aza-fulvene-type acylazolium intermediate. A broad range of N-heteroaromatic aldehydes and electron-deficient ketone substrates works effectively in this transformation. Several of the chiral N,O-acetal products afforded through this protocol exhibit excellent antibacterial activities against Ralstonia solanacearum (Rs) and
Nucleophilic β-Carbon Activation of Propionic Acid as a 3-Carbon Synthon by Carbene Organocatalysis
作者:Zhichao Jin、Ke Jiang、Zhenqian Fu、Jaume Torres、Pengcheng Zheng、Song Yang、Bao-An Song、Yonggui Robin Chi
DOI:10.1002/chem.201501481
日期:2015.6.22
Direct β‐carbonactivation of propionic acid (C2H5CO2H) by carbene organocatalysis has been developed. This activation affords the smallest azolium homoenolate intermediate (without any substituent) as a 3‐carbon nucleophile for enantioselective reactions. Propionic acid is an excellent raw material because it is cheap, stable, and safe. This approach provides a much better solution to azolium homoenolate
已经开发了通过卡宾有机催化作用对丙酸(C 2 H 5 CO 2 H)进行直接β-碳活化。这种活化提供了最小的均氮唑鎓中间体(无任何取代基),作为对映选择性反应的3碳亲核试剂。丙酸是便宜,稳定和安全的原料,因此是一种极好的原料。这种方法比以前建立的丙烯醛(没有任何取代基的烯醛)使用昂贵,不稳定且有毒的方法提供了更好的解决方案,用于合成均氮唑鎓。
β-Functionalization of Carboxylic Anhydrides with β-Alkyl Substituents through Carbene Organocatalysis
作者:Zhichao Jin、Shaojin Chen、Yuhuang Wang、Pengcheng Zheng、Song Yang、Yonggui Robin Chi
DOI:10.1002/anie.201408604
日期:2014.12.1
The first NHC‐catalyzed functionalization of carboxylicanhydrides is described. In this reaction, the β carbon behaves as a nucleophilic carbon and undergoes asymmetric reactions with electrophiles. Anhydrides with challenging β‐alkyl substituents work effectively.
Chemoselective Intermolecular Cross-Benzoin Reaction of Aliphatic Aldehydes and Isatins via N-Heterocyclic Carbene Catalysis
作者:Haojie Ji、Jianfeng Xu、Hongjun Ren
DOI:10.1055/s-0037-1612250
日期:2019.5
cross-benzoin reaction of aliphaticaldehydes with isatins is developed, affording biologically important 3-substituted 3-hydroxyoxindoles (on gram scale) in moderate to good yields (46–90%). The employment of a morpholinone-derived pentafluorophenyl-substituted triazolium salt as the electron-deficient NHC pre-catalyst is essential to make the reaction go through the cross-benzoin reaction pathway rather