RETRACTED: Asymmetric synthesis of highly enantioenriched 2-substituted piperidines and 6-substituted piperidine-2-ones by a combination enantioselective hydrazone allylation with ring closing metathesis
摘要:
An efficient method for the asymmetric synthesis of highly optically pure 2-substituted piperidines and 6-substituted piperidine-2-ones from aldehydes was developed by a sequence of enantioselective hydrazone allylation and ring closing metathesis. This method was found to be effective for a variety of substrates, showing substrate generality. The method's synthetic utility was illustrated in concise synthesis of the alkaloid (R)-(-)-coniine. (C) 2012 Elsevier Ltd. All rights reserved.
Radical “On Water” Addition to the C═N Bond of Hydrazones: A Synthesis of Isoindolinone Derivatives
作者:Tae Kyu Nam、Doo Ok Jang
DOI:10.1021/acs.joc.7b03193
日期:2018.7.20
A radical “on water” addition to the C═Nbond of hydrazones has been described. Hydrazone, diphenylsilane, alkyl iodide, and triethylborane afforded the corresponding addition products “on water” in good yields. A significant solvent effect was observed from the water. The developed protocol can be applied to the synthesis of 3-substituted isoindolinone derivatives. Moreover, the process offers environmentally
Facile construction of novel imidazolidine-spirooxindoles via diastereoselective cycloaddition of N-acylhydrazine-derived imines with 3-isothiocyanato oxindoles
presence of 10 mol% of Na2CO3, the desired imidazolidine-spirooxindoles were obtained in 81–99% yield with up to 99 : 1 dr by means of the diastereoselective [3 + 2] cycloaddition of N-acylhydrazine-derived imines with 3-isothiocyanatooxindoles. Single-crystal X-ray structure analysis was conducted to determine the relative stereochemistry of the imidazolidine-spirooxindoles. Diastereoselective access
在存在10 mol%的Na 2 CO 3时,通过衍生自N-酰基肼的非对映选择性[3 + 2]环加成反应,可以81-99%的收率获得所需的咪唑烷-螺氧并吲哚,最高可达99:1 dr。亚胺与3-异硫氰酸根合吲哚。进行了单晶X射线结构分析,以确定咪唑烷-螺氧还吲哚的相对立体化学。拟议的机制假设非对映选择性进入咪唑烷-spirooxindoles。
Efficient oxidative cyclization of <i>N</i>-acylhydrazones for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles using <i>t</i>-BuOI under neutral conditions
作者:Peng Gao、Yunyang Wei
DOI:10.1515/hc-2012-0179
日期:2013.4.1
in situ from t-BuOCl and NaI. A variety of 2,5-disubstituted1,3,4-oxadiazoles were synthesized in high yields within short reaction time. The method is also suitable for cyclization of N-acylhydrazones derived from heterocyclic aldehydes and aliphatic aldehydes. Mild reaction conditions and simple workup operations make the procedure a good alternative for the synthesis of 2,5-disubstituted 1,3,4-oxadiazoles
Indium-Mediated Catalytic Enantioselective Allylation of <i>N</i>-Benzoylhydrazones Using a Protonated Chiral Amine
作者:Sung Jun Kim、Doo Ok Jang
DOI:10.1021/ja1035336
日期:2010.9.8
A catalytic enantioselective indium-mediatedallylation of N-benzoylhydrazones in conjunction with a protonated chiral amine affording enantioenriched homoallylic amines with an extremely high level of enantioselectivity and chemical yield was developed.
Alkyl Radical Addition to Aliphatic and Aromatic <i>N</i>-Acylhydrazones Using an Organic Photoredox Catalyst
作者:Stephen T. J. Cullen、Gregory K. Friestad
DOI:10.1021/acs.orglett.9b03053
日期:2019.10.18
biscatecholatosilicates with organocatalyst 4CzIPN, add successfully to both aromatic and aliphatic N-acylhydrazones in the presence of MgCl2. With N-benzoylhydrazones, a simplereductivecleavage of the N–N bond of the hydrazine adduct furnishes the free amine. Synthetic utility is exemplified in a synthetic application toward repaglinide, a clinically important hypoglycemic agent.