In the present work, the highly efficient Erlenmeyer synthesis of azlactones catalyzed by 2- aminopyridine, supported on nano-sphere Si02 is reported. First, the silica nanoparticles were modified with triethoxysilylp...In the present work, the highly efficient Erlenmeyer synthesis of azlactones catalyzed by 2- aminopyridine, supported on nano-sphere Si02 is reported. First, the silica nanoparticles were modified with triethoxysilylpropyl chloride and then 2-aminopyridine was attached to the support via covalent linkages. This new heterogenized catalyst was used for efficient microwave-assisted synthesis of azlactone derivatives with Ac20 as a condensing agent under solvent-free conditions. The present method offers advantages including high yields, short reaction times and simple work-up. Also, the catalyst can be easily recycled and reused several times, which makes this method attractive, economic and environmentally-benign.展开更多
The chiral phosphoric acid catalyzed asymmetric[3+2]annulation of substituted 2-vinylindoles with azlactones has been established.This reaction represented a practical approach for the synthesis of structurally divers...The chiral phosphoric acid catalyzed asymmetric[3+2]annulation of substituted 2-vinylindoles with azlactones has been established.This reaction represented a practical approach for the synthesis of structurally diverse pyrrolo[1,2-a]indoles with two vicinal stereocenters including one tetrasubstituted stereocenter in good yields and good stereoselectivities under mild conditions.展开更多
An efficient asymmetric[4+2]cyclization of hydroxyphenyl indolinone with azlactone for the synthesis of spirooxindoleδ-lactone has been developed,which realized the first asymmetric reaction of hydroxyphenyl indolino...An efficient asymmetric[4+2]cyclization of hydroxyphenyl indolinone with azlactone for the synthesis of spirooxindoleδ-lactone has been developed,which realized the first asymmetric reaction of hydroxyphenyl indolinone.A series of intricate structures with congested vicinal quaternary chiral centers were provided in good yields with excellent enantioselectivities via the in situ generated o-QM from hydroxyphenyl indolinone.展开更多
Herein,we report an organocatalytic asymmetric[8+2]higher-order cycloaddition of tropones with azlactones employing bifunctional guanidines as hydrogen-bond-mediated catalysts via a 1,8-addition/annulation process.The...Herein,we report an organocatalytic asymmetric[8+2]higher-order cycloaddition of tropones with azlactones employing bifunctional guanidines as hydrogen-bond-mediated catalysts via a 1,8-addition/annulation process.The reaction has a broad scope with respect to both cycloaddition partners and hence offers rapid access to an array of[5.3.0]bicyclic compounds with excellent outcomes[up to 95%yield,>19:1 diastereomeric ratio(dr),and 96%enantiomeric excess(ee)].Besides,the synthetic utility of the protocol provides rapid transformation into enantioenrichedα-amino acid derivatives.Moreover,the isolated[1,5]-H shift isomer,X-ray crystal structure of chiral guanidinium salt,and density functional theory(DFT)calculations provide convincing evidence for the interpretation of diastereo-and enantioselection.展开更多
A novel method for the asymmetric synthesis of 1,7-annulated indazoles has been developed via bifunctional Brønsted base catalyzed cascade reaction.This process enabled the formation of multiple chiral centers in...A novel method for the asymmetric synthesis of 1,7-annulated indazoles has been developed via bifunctional Brønsted base catalyzed cascade reaction.This process enabled the formation of multiple chiral centers including a quaternary carbon center in high yields with excellent diastereoselectivities and enantioselectivities.The reaction exhibited broad functional group tolerance and mild reaction conditions.展开更多
The macrophage migration inhibitory factor has been implicated in a number ofimmune and inflammatory processes. MIF presents particular opportunities for drug design anddevelopment with potential therapeutic applicati...The macrophage migration inhibitory factor has been implicated in a number ofimmune and inflammatory processes. MIF presents particular opportunities for drug design anddevelopment with potential therapeutic applications. Drug design strategies taking intoconsideration of specific stereochemical and tautomeric requirements in the interaction of MIF withsubstrates and inhibitors allow several novel structures to be designed. Our investigationssuccessfully explored the tautomeric and stereochemical aspects of new compounds of the2-phenylpyruvic acid type, both experimentally, through synthesis and structural investigations andcomputationally, through molecular mechanics and quantum mechanics calculations.展开更多
基金financial support from the Research Council of Arak University
文摘In the present work, the highly efficient Erlenmeyer synthesis of azlactones catalyzed by 2- aminopyridine, supported on nano-sphere Si02 is reported. First, the silica nanoparticles were modified with triethoxysilylpropyl chloride and then 2-aminopyridine was attached to the support via covalent linkages. This new heterogenized catalyst was used for efficient microwave-assisted synthesis of azlactone derivatives with Ac20 as a condensing agent under solvent-free conditions. The present method offers advantages including high yields, short reaction times and simple work-up. Also, the catalyst can be easily recycled and reused several times, which makes this method attractive, economic and environmentally-benign.
基金supported by the Fundamental Research Funds for the Central Universitiesthe China Postdoctoral Science Foundation(Nos.2018M632037,2019T120310)Shanghai Sailing Program(No.18YF140560)。
文摘The chiral phosphoric acid catalyzed asymmetric[3+2]annulation of substituted 2-vinylindoles with azlactones has been established.This reaction represented a practical approach for the synthesis of structurally diverse pyrrolo[1,2-a]indoles with two vicinal stereocenters including one tetrasubstituted stereocenter in good yields and good stereoselectivities under mild conditions.
基金We thank the Qingdao Marine Science and Technology Center(No.2022QNLM030003-2)the Fundamental Research Funds for the Central Universities,Taishan Scholar Program of Shandong Province(No.tsqn201909056)National Natural Science Foundation of China(No.22171251)for financial support.
文摘An efficient asymmetric[4+2]cyclization of hydroxyphenyl indolinone with azlactone for the synthesis of spirooxindoleδ-lactone has been developed,which realized the first asymmetric reaction of hydroxyphenyl indolinone.A series of intricate structures with congested vicinal quaternary chiral centers were provided in good yields with excellent enantioselectivities via the in situ generated o-QM from hydroxyphenyl indolinone.
文摘Herein,we report an organocatalytic asymmetric[8+2]higher-order cycloaddition of tropones with azlactones employing bifunctional guanidines as hydrogen-bond-mediated catalysts via a 1,8-addition/annulation process.The reaction has a broad scope with respect to both cycloaddition partners and hence offers rapid access to an array of[5.3.0]bicyclic compounds with excellent outcomes[up to 95%yield,>19:1 diastereomeric ratio(dr),and 96%enantiomeric excess(ee)].Besides,the synthetic utility of the protocol provides rapid transformation into enantioenrichedα-amino acid derivatives.Moreover,the isolated[1,5]-H shift isomer,X-ray crystal structure of chiral guanidinium salt,and density functional theory(DFT)calculations provide convincing evidence for the interpretation of diastereo-and enantioselection.
基金the Qingdao Marine Science and Technology Center(No.2022QNLM030003-2)the Fundamental Research Funds for the Central Universities,Taishan Scholar Program of Shandong Province(No.tsqn201909056)+1 种基金Natural Science Foundation of Shandong Province(No.ZR2024MB122)National Natural Science Foundation of China(No.22171251)for financial support.
文摘A novel method for the asymmetric synthesis of 1,7-annulated indazoles has been developed via bifunctional Brønsted base catalyzed cascade reaction.This process enabled the formation of multiple chiral centers including a quaternary carbon center in high yields with excellent diastereoselectivities and enantioselectivities.The reaction exhibited broad functional group tolerance and mild reaction conditions.
文摘The macrophage migration inhibitory factor has been implicated in a number ofimmune and inflammatory processes. MIF presents particular opportunities for drug design anddevelopment with potential therapeutic applications. Drug design strategies taking intoconsideration of specific stereochemical and tautomeric requirements in the interaction of MIF withsubstrates and inhibitors allow several novel structures to be designed. Our investigationssuccessfully explored the tautomeric and stereochemical aspects of new compounds of the2-phenylpyruvic acid type, both experimentally, through synthesis and structural investigations andcomputationally, through molecular mechanics and quantum mechanics calculations.
