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
Iodine-Catalyzed Oxidation of<i>N</i>-Substituted Indoles by using Chloramine-B: A Facile and Practical Approach to Isatins
作者:Peijun Liu、Jiajing Guo、Wentao Wei、Xiaozu Liu、Pinghua Sun
DOI:10.1002/ejoc.201600061
日期:2016.4
An efficient method for the iodine-catalyzed oxidation of N-substituted indoles by using chloramine-B under mild reaction conditions was explored. This reaction was found to be tolerant to a variety of functional groups and provided the corresponding isatins in moderate to excellent yields. In addition, application of this method to the one-pot synthesis of 3-hydroxyoxindole and N-methylisatin oxime
A Ni-catalyzed addition of arylboronic acids to isatins was first developed. The reaction, driven by Ni(acac)2 and dppp as the phosphine ligand, gave 3-aryl-3-hydroxy-2-oxindoles in up to 97% yield. Scopes of benzyl-protected isatins and arylboronic acids were examined. Substituted phenylboronic acids along with fused-ring and heterocyclic boronic acids reacted with isatins smoothly. Preliminary asymmetric
The synthesis of new chloramphenicol base‐derived chiral hydroxyl oxazolineligands, and their use in the first Zn(OTf)2‐catalyzed enantioselective alkynylation of isatins are described. This transformation features mild reaction conditions, a remarkably broad substrate scope, and excellent functional group tolerance, affording the corresponding tertiary propargylic alcohols in high yields and with
The catalyticasymmetric ene-type reactions of vinylogous hydrazone were accomplished by using chiral N,N′-dioxide–metal salt complexes as catalysts. A wide range of electrophiles, including isatins, α-ketoester, imines, and aldehydes reacted with (E)-2-methyl-N-(piperidin-1-yl)prop-2-en-1-imine efficiently, affording the corresponding homoallylicalcohols and amines in high yields (up to 99%) with