o-Acylbenzonitriles: Synthesis and Heterocyclization under Acid Hydrolysis of the Cyano Group
摘要:
2-Cyanobenzophenones were synthesized by reaction of 2-bromobenzophenones with copper(I) cyanide in DMF, and their transformations involving acid hydrolysis of the cyano group were studied. Reactions of o-benzoylbenzonitriles with trifluoroacetic acid in the presence or in the absence of sulfuric acid afforded 3-hydroxyphthalimidines in high yields. Under analogous conditions, benzonitriles having no acyl group in the ortho position were converted to the corresponding benzamides. 2-Cyanobenzophenones reacted with sulfuric acid in the absence of trifluoroacetic acid to give only substituted anthraquinones.
A chiral Brønsted acid-catalyzed highly enantioselective Mannich-type reaction of α-diazo esters with <i>in situ</i> generated <i>N</i>-acyl ketimines
作者:Rajshekhar A. Unhale、Milon M. Sadhu、Sumit K. Ray、Rayhan G. Biswas、Vinod K. Singh
DOI:10.1039/c8cc01436a
日期:——
A chiral phosphoric acid-catalyzed asymmetricMannich-typereaction of α-diazo esters with in situ generated N-acyl ketimines, derived from 3-hydroxyisoindolinones has been demonstrated in this communication. A variety of isoindolinone-based α-amino diazo esters bearing a quaternary stereogenic center were afforded in high yields (up to 99%) with excellent enantioselectivities (up to 99% ee). Furthermore
Asymmetric hydrogenolysis of racemic 3-substitued-3-hydroxy-isoindolin-1-ones employing SPINOL-derived chiral phosphoric acid
作者:Yiliang Zhang、Li He、Lei Shi
DOI:10.1016/j.tetlet.2018.03.030
日期:2018.4
The asymmetric hydrogenolysis of racemic 3-substitued-3-hydroxyisoindolin-1-ones has been developed employing SPINOL-derived phosphoric acid and a high steric demand Hantzsch ester as the hydrogen source. The corresponding products are obtained in good yields and up to 93% enantioselectivities.
Enantioselective Addition of Enamides to Cyclic Ketimines: Access to Chiral 3,3‐Disubstituted Isoindolin‐1‐Ones
作者:Fang‐Fang Feng、Jin‐Shan Li、Shen Li、Jun‐An Ma
DOI:10.1002/adsc.201900710
日期:2019.9.17
An enantioselectiveaddition of enamides to cyclicketimines generated in situ from 3‐hydroxyisoindolin‐1‐ones was developed. This reaction takes advantage of readily available substrates, mild reaction conditions, as well as enlarged reaction generality, affording chiral 3,3‐disubstituted isoindolin‐1‐ones with a quaternary stereogenic center in high yields (up to 98%) and enantioselectivities (up
BF<sub>3</sub>·OEt<sub>2</sub>-Catalyzed Vinyl Azide Addition to in Situ Generated <i>N</i>-Acyl Iminium Salts: Synthesis of 3-Oxoisoindoline-1-acetamides
作者:Deb Kumar Das、Vinod Kumar Kannaujiya、Milon M. Sadhu、Sumit Kumar Ray、Vinod K. Singh
DOI:10.1021/acs.joc.9b02127
日期:2019.12.20
BF3·OEt2-catalyzed nucleophilic addition of vinyl azides to in situ generated N-acyl iminium salts obtained from 3-hydroxyisoindolinones is described in this article. The procedure is operationally simple, mild, additive, and metal-free. The reaction proceeds smoothly at ambient temperature with a wide range of 3-hydroxyisoindol-1-ones and vinyl azides to afford 3-oxoisoindoline-1-acetamides (32 examples)
Catalytic Enantioselective Synthesis of Difluoromethylated Tetrasubstituted Stereocenters in Isoindolones Enabled by a Multiple-Fluorine System
作者:Meng-Yu Rong、Jin-Shan Li、Yin Zhou、Fa-Guang Zhang、Jun-An Ma
DOI:10.1021/acs.orglett.0c03406
日期:2020.11.20
This unique multiple-fluorine system provides rapid access to difluoromethylated tetrasubstituted stereocenters in isoindolones with wide substrate scope under mild conditions. Further synthetic transformations to enantioenriched CF2H-isoindolones and CF2-decorated fused isoindolones were also implemented with good efficiency.