Synthesis of Chromeno[3,4-c]Pyrazole from N-Tosylhydrazones and 3-Nitro-2-Phenyl-2H-Chromene

The intermolecular 1,3-dipolar cycloaddition of N-tosylhydrazones and 3-nitro-2-phenyl-2 H-chromene afforded 1-aryl-4-phenyl-2,4-dihydro-chromeno[3,4- c]pyrazoles in moderate to good yields. The structures of all the products were characterised by NMR, IR, HRMS and X-ray crystallographic analysis.

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Synthesis of Octahydropyrano[2,3-d]Pyrimidine Derivatives via Tetrahydropyrano[3,2-e][1,3]Thiazolo[3,2-a]Pyrimidine and 2,6-Dichlorobenzonitrile Oxide

Journal of Chemical Research ◽

10.3184/174751918x15293130141511 ◽

2018 ◽

Vol 42 (6) ◽

pp. 317-319

Author(s):

Qing Zeng ◽

Demin Ren ◽

Aiting Zheng ◽

Xiaofang Li

Keyword(s):

Ring Opening ◽

Crystallographic Analysis ◽

Dipolar Cycloaddition ◽

Pyrimidine Derivatives ◽

X Ray ◽

Moderate Yield

N1-substituted octahydro-1 H-pyrano[2,3- d]pyrimidines derivatives were prepared in moderate yield by the reaction of methyl [(4a RS,5 SR,10a RS)-5-aryl-2-oxo-3,4,4 a,10 a-tetrahydro-2 H,5 H-pyrano[3,2- e][1,3]thiazolo[3,2- a]pyrimidin-8(9 H)-ylidene]acetate and 2,6-dichorobenzonitrile oxide via a domino 1,3-dipolar cycloaddition/ring-opening/dethionation process. The structures of the products were characterised by spectroscopic and X-ray crystallographic analysis.

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Diastereoselective Synthesis of Spiro[Pyrrolo[2,1-B][1,3] Benzothiazole-3,5′-[1,3]Thiazolo[3,2-B][1,2,4]Triazol]-6′-Ones via Cycloaddition Reaction of Benzothiazolium Salts

Journal of Chemical Research ◽

10.3184/174751918x15314846558430 ◽

2018 ◽

Vol 42 (7) ◽

pp. 371-373 ◽

Cited By ~ 6

Author(s):

Qing Zeng ◽

Demin Ren ◽

Yulin Huang ◽

Xinliang Fu ◽

Xiaofang Li

Keyword(s):

Cycloaddition Reaction ◽

Crystallographic Analysis ◽

Azomethine Ylide ◽

Dipolar Cycloaddition ◽

Diastereoselective Synthesis ◽

X Ray

The 1,3-dipolar cycloaddition reaction of (Z)-5-arylidene[1,3]thiazolo[3,2-b][1,2,4]triazol-6(5H)-one and azomethine ylide, which was generated in situ by the reaction of N-4-methoxyphenacylbenzothiazolium bromides and triethylamine, afforded novel 2-(aryl)-1-(4-methoxybenzoyl)-1,2-dihydrospiro[pyrrolo[2,1-b][1,3]benzothiazole-3,5′-[1,3]thiazolo[3,2-b][1,2,4]triazol]-6′-ones in moderate yields. The structures of all the products were characterised thoroughly by NMR, IR and HRMS spectroscopy together with X-ray crystallographic analysis.

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Regio- and Stereoselectivity in the 1,3-Dipolar Cycloaddition Reactions of Isoquinolinium Ylides with Cyclopenta[a]acenaphthylen-8-ones

Synlett ◽

10.1055/s-0040-1706750 ◽

2020 ◽

Vol 31 (17) ◽

pp. 1691-1695

Author(s):

Issa Yavari ◽

Parisa Ravaghi ◽

Maryam Safaei ◽

Jasmine Kayanian

Keyword(s):

Dft Calculations ◽

Cycloaddition Reaction ◽

Crystallographic Analysis ◽

Dipolar Cycloaddition ◽

Cycloaddition Reactions ◽

Diastereoselective Synthesis ◽

X Ray

AbstractA convenient regio- and diastereoselective synthesis of functionalized 5a,5b-dihydro-5H,13H-naphtho[1′′,8′′:4′,5′,6′]pentaleno[1′:3,4]pyrrolo[2,1-a]isoquinolin-5-ones via 1,3-dipolar cycloaddition reaction of 8H-cyclopenta[a]acenaphthylen-8-ones with carbonyl-stabilized isoquinolinium N-ylides, is described. Based on DFT calculations at b3lyp/6-311+g(d,p) level of theory, a nonconcerted mechanism is proposed to explain the regioselectivity of this reaction. The structure of a typical product was confirmed by X-ray crystallographic analysis.

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Synthesis of Dispiro[Indeno[1,2-b]Quinoxaline-11,3′-Pyrrolizine-2′,2″-[1,3] Thiazolo[3,2-a]Pyrimidine Via Cycloaddition Reactions

Journal of Chemical Research ◽

10.3184/174751918x15349264445767 ◽

2018 ◽

Vol 42 (9) ◽

pp. 453-455 ◽

Cited By ~ 6

Author(s):

Demin Ren ◽

Xiaolian Hu ◽

Yulin Huang ◽

Xiaofang Li

Keyword(s):

Cycloaddition Reaction ◽

Crystallographic Analysis ◽

Azomethine Ylide ◽

Dipolar Cycloaddition ◽

Cycloaddition Reactions ◽

X Ray

The 1,3-dipolar cycloaddition reaction of ethyl 5-aryl-2-(2-methoxy-2-oxoethylidene)-7-methyl-3-oxo-2,3-dihydro-5 H-[1,3]thiazolo[3,2- a] pyrimidine-6-carboxylate and azomethine ylide, which was generated in situ by the reaction of 11 H-indeno[1,2- b]quinoxalin-11-one and L-proline, afforded novel 6″ethyl 1′-methyl 5″aryl-7″methyl-3″oxo-5’,6’,7’,7a′-tetrahydro-1' H,3″ H,5″ H-dispiro[indeno[1,2- b]quinoxaline-11, 3 ‘-pyrrolizine-2’,2″-[1,3]thiazolo[3,2- a]pyrimidine-1’,6″-dicarboxylates in good yields. The structures of all the products were characterised thoroughly by NMR, IR and HRMS together with X-ray crystallographic analysis.

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Synthesis of novel dispiro[indazole-5,3′-pyrrolidine-2′,3″-indole] derivatives via 1,3-dipolar cycloaddition of azomethine ylide

Journal of Chemical Research ◽

10.3184/174751917x14981229444848 ◽

2017 ◽

Vol 41 (7) ◽

pp. 427-429

Author(s):

Demin Ren ◽

Guoqiang Kuang ◽

Xiaolian Hu ◽

Xiaofang Li

Keyword(s):

Crystallographic Analysis ◽

Azomethine Ylide ◽

Dipolar Cycloaddition ◽

Indole Derivatives ◽

X Ray

The 1,3-dipolar cycloaddition of azomethine ylide, generated in situ from isatin and sarcosine, to 5-arylmethylidene-1-phenyl-6,7-dihydro-1 H-indazol-4(5 H)-ones afforded novel 1′-methyl-4′-aryl-1-phenyl-6,7-dihydrodispiro[indazole-5,3′-pyrrolidine-2′,3″-indole]-2″,4(1 H,1″ H)-diones in moderate yields. The structures of all the products were characterised thoroughly by NMR, IR, HRMS, together with X-ray crystallographic analysis.

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Synthesis of Spiro[Pyrrolo[2,1-b][1,3]Benzothiazole-3,2′-[1,3]Thiazolo[3,2-a] Pyrimidine] via Cycloaddition Reactions

Journal of Chemical Research ◽

10.3184/174751918x15260567362969 ◽

2018 ◽

Vol 42 (5) ◽

pp. 260-263 ◽

Cited By ~ 2

Author(s):

Qing Zeng ◽

Demin Ren ◽

Xingliang Fu ◽

Xiaofang Li

Keyword(s):

Cycloaddition Reaction ◽

Crystallographic Analysis ◽

Azomethine Ylide ◽

Dipolar Cycloaddition ◽

Cycloaddition Reactions ◽

X Ray

The 1,3-dipolar cycloaddition reaction of ethyl-5-aryl-2-[( Z)-2-methoxy-2-oxoethylidene]-7-methyl-3-oxo-3,5-dihydro-2 H-thiazolo[3,2- a] pyrimidine-6-carboxylates and azomethine ylide, which was generated in situ by the reaction of N-4-methoxyphenacylbenzothiazolium bromides and triethylamine, yielded novel 6′-ethyl-2-methyl-5′-aryl-1-(4-methoxybenzoyl)-7-methyl-3′-oxo-1,2-dihydro-5 H-spiro[pyrrolo[2,1- b][1,3]benzothiazole-3,2′-[1,3]thiazolo[3,2- a]pyrimidine]-2,6′-dicarboxylates in moderate yields. The structures of all of the products were characterised by NMR, IR, HRMS spectrometry, together with X-ray crystallographic analysis.

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Synthesis of spiro[cyclopent-2/3-ene-1,2′-[1,3]thiazolo[3,2-a] pyrimidine] derivatives via 1,3-dipolar cycloaddition reaction of ethyl buta-2,3-dienoate

Journal of Chemical Research ◽

10.3184/174751918x15426290490753 ◽

2018 ◽

Vol 42 (12) ◽

pp. 631-635 ◽

Cited By ~ 1

Author(s):

Demin Ren ◽

Ye Tang ◽

Xianyong Yu ◽

Yulin Huang ◽

Xiaofang Li

Keyword(s):

Cycloaddition Reaction ◽

Crystallographic Analysis ◽

Dipolar Cycloaddition ◽

Pyrimidine Derivatives ◽

X Ray

The 1,3-dipolar cycloaddition reaction of ethyl (2Z)-5-aryl-2-(2-methoxy-2-oxoethylidene)-7-methyl-2,3-dihydro-5H-thiazolo[3,2-a] pyrimidine-6-carboxylate and ethyl buta-2,3-dienoate catalysed by triphenylphosphine afforded novel spiro[cyclopent-2-ene-1,2′-[1,3] thiazolo[3,2-a]pyrimidine] and spiro[cyclopent-3-ene-1,2′-[1,3]thiazolo[3,2-a]pyrimidine] derivatives in moderate yields. The structures of all the products were characterised thoroughly by NMR, IR and HRMS together with X-ray crystallographic analysis.

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Quaternary structure of Limulus polyphemus hemocyanin

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081747 ◽

1978 ◽

Vol 36 (2) ◽

pp. 176-177

Author(s):

T. Wichertjes ◽

E.J. Kwak ◽

E.F.J. Van Bruggen

Keyword(s):

Electron Microscopy ◽

Functional Properties ◽

Horseshoe Crab ◽

Temperature Jump ◽

Quaternary Structure ◽

Crystallographic Analysis ◽

Limulus Polyphemus ◽

Oxygen Binding ◽

X Ray ◽

Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

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