X-RAY ANALYSIS OF PYRROLIZIDINES SYNTHESIZED BY DIASTEREOSELECTIVE α-CYCLISATION OF CAPTODATIVE OR PUSH-PULL ENAMINES WITH DIMETHYL ACETYLENEDICARBOXYLATE

2010 ◽  
Vol 104 (6) ◽  
pp. 397-400 ◽  
Author(s):  
B. Tinant ◽  
J. Feneau-Dupont ◽  
J. P. Declercq ◽  
B. De Boeck ◽  
S. Jiang ◽  
...  
Keyword(s):  
Dimethyl Acetylenedicarboxylate ◽  
X Ray

Heterocyclisation of substituted ylidenethiocarbonohydrazides using dimethyl acetylenedicarboxylate

2015 ◽  
Vol 69 (7) ◽  
Author(s):  
Alaa A. Hassan ◽  
Fathy F. Abdel-Latif ◽  
Mohamed Abdel Aziz ◽  
Sara M. Mostafa ◽  
Stefan Bräse ◽  
...  
Keyword(s):  
Single Crystal ◽  
Condensation Reaction ◽  
Dimethyl Acetylenedicarboxylate ◽  
Rapid Procedure ◽  
X Ray

AbstractA facile and rapid procedure for the synthesis of dimethyl-2-[3-amino-5-(2-methoxy-2-oxoethylidene)- 4-oxothiazolidin-2-ylidenehydrazono]succinate, dimethyl {[2-alkylidenehydrazono)-5-(2-methoxy- 2-oxoethylidene)-4-oxothiazolidin-3-yl)amino]succinate and methyl (4-amino-5-oxo-3- thioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-yl)acetate affording yields of 61-54 %, 22-18 % and 14- 11 %, respectively, via a condensation reaction of dimethyl acetylenedicarboxylate (DMAD) with (substituted ylidene)thiocarbonohydrazides. One of the products was conclusively confirmed by single-crystal X-ray analysis. A mechanism for the formation of the products is presented.

Synthesis and crystal structures of three novel benzimidazole/benzoindolizine hybrids

2016 ◽  
Vol 71 (3) ◽  
pp. 231-239 ◽  
Author(s):  
Roumaissa Belguedj ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Ali Belfaitah ◽  
Aissa Chibani ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimethyl Maleate

AbstractThree benzoindolizine derivatives, 1, 2, and 3, were obtained via 1,3-dipolar cycloaddition. The reaction of 1-(2′-benzimidazolylmethyl)isoquinolinium ylides with dimethyl acetylenedicarboxylate gave a mixture of pyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (1) and 1,10b-dihydropyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (2) derivatives containing a benzimidazole moiety. The reaction of this isoquinolinium N-ylide with dimethyl maleate gave an unexpected 2,3-dihydropyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (3). The structures of all reported compounds have been examined by X-ray crystallography, mass spectrometry, and NMR spectroscopy.

ChemInform Abstract: X-Ray Analysis of Pyrrolizidines Synthesized by Diastereoselective . alpha.-Cyclization of Captodative or Push-Pull Enamines with Dimethyl Acetylenedicarboxylate.

ChemInform ◽  
2010 ◽  
Vol 26 (37) ◽  
pp. no-no
Author(s):  
B. TINANT ◽  
J. FENEAU-DUPONT ◽  
J. P. DECLERCQ ◽  
B. DE BOECK ◽  
S. JIANG ◽  
...  
Keyword(s):  
Dimethyl Acetylenedicarboxylate ◽  
X Ray

Einfache Synthese von 2,2-Diethoxy-2,5-dihydrofuranen, 2(5 H)Furanonen und 2-Ethoxy-furanen.Kristall-und Molekülstruktur eines Barrelenon Diels-Aider Produktes [1] / Convenient Synthesis of 2,2-Diethoxy-2,5-dihydrofurans, 2(5 H)Furanones and 2-Ethoxyfurans.Crystal and Molecular Structure of a Barrelenone Diels-Alder Product [1]

1994 ◽  
Vol 49 (3) ◽  
pp. 389-406 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Wieland Hafner ◽  
Joachim Markmann ◽  
Andreas Welch ◽  
Karl Peters ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Maleic Anhydride ◽  
Structure Analysis ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Reaction Conditions ◽  
X Ray ◽  
Convenient Synthesis

AbstractReaction of 1,2-hydroxyketones 5 with (2,2-diethoxyvinylidene)triphenylphosphorane (2) or (2,2-diethoxyvinyl)triphenylphosphonium tetrafluoroborates 6 yields the 2,2-diethoxy- 2.5-dihydrofurans 9. Depending on the reaction conditions used, the orthoesters 9 can be hydrolized to give 2(5 H)furanones 10 and 2-ethoxyfurans 11, respectively. 4,5-Dimethyl- 5.6-dihydro-2-pyranone (20) and 8-methoxycoumarin (23) are prepared, starting from (2,2-diethoxyvinyl)triphenylphosphonium tetrafluoroborate (6 a) and 1-hydroxy-2-methyl- 3-butanone (16) or 2-hydroxy-3-methoxy-benzaldehyde (21). The 2-ethoxyfuranes 11 readily undergo Diels-Alder reactions with 2-chloracrylonitrile (24), maleic anhydride (26), N-phenyl-1,2,4-triazoline-3,5-dione (28) and dimethyl acetylenedicarboxylate (30) to give the corresponding Diels-Alder products 25, 27, 29 and 31, respectively. Contrary to 2-ethoxyfuran 11b , 11a reacts with two equivalents of acetylene 30, to yield barrelenone 34. The structure of 34 unequivocally is established by X-ray structure analysis.

Corroles in 1,3-dipolar cycloaddition reactions

2009 ◽  
Vol 13 (03) ◽  
pp. 358-368 ◽  
Author(s):  
Luís S. H. P. Vale ◽  
Joana F. B. Barata ◽  
Carla I. M. Santos ◽  
Maria G. P. M. S. Neves ◽  
Maria A. F. Faustino ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Dimethyl Fumarate ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dipolar Cycloadditions ◽  
Pyridine Complex

The azomethine ylide generated from the reaction of a corrole-3-carbaldehyde and N-methylglycine was trapped with dimethyl fumarate, dimethyl acetylenedicarboxylate and fullerene C60 in 1,3-dipolar cycloadditions. A similar azomethine ylide generated from a corrole-2-carbaldehyde was trapped with 1,4-naphthoquinone, yielding the expected dehydrogenated 1,3-dipolar cycloadduct and a quinone-fused corrole derivative. A detailed synchrotron single-crystal X-ray diffraction analysis of the gallium(III)(pyridine) complex of 5,10,15-tris(pentafluorophenyl)corrole-3-carbaldehyde is also presented.

Spiro fused β-lactam cyclopropenes

1992 ◽  
Vol 70 (12) ◽  
pp. 2967-2971 ◽  
Author(s):  
Michel Zoghbi ◽  
John Warkentin
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
Strain Energy ◽  
High Strain ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray Diffraction ◽  
Cyclopropene Ring ◽  
X Ray ◽  
Lactam Ring ◽  
High Strain Energy

Δ3-1,3,4-Oxadiazolines (1) that share their C2 with C4 of a β-lactam ring in a spiro fusion were prepared. The structures were established through single crystal X-ray diffraction of 1a and by infrared, 1H, and 13C nuclear magnetic resonance spectroscopies. Thermolysis of 1 at 100 °C, in benzene containing dimethyl acetylenedicarboxylate, afforded spiro-fused β-lactam cyclopropene 12 in 33% yield. Similar thermolysis of 1b in the presence of ethyl phenylpropiolate gave spiro-fused β-lactam cyclopropene 13 (32%). The molecular structure of 12, determined by single crystal X-ray diffraction, has the two ester carbonyl carbons out of the plane of the cyclopropene ring by about 0.17 Ǻ, indicating substantial nonbonded steric interactions and suggesting unusually high strain energy. At 154.5 °C, 12 underwent isomerization to 19, presumably through a vinyl carbene intermediate.

scholarly journals Two-Carbon Ring Enlargement of Five-, Six-, and Seven-Membered 1-Aza-2-vinylcycloalk-2-enes with Dimethyl Acetylenedicarboxylate and Subsequent Thermal Isomerization Reactions

2006 ◽  
Vol 61 (4) ◽  
pp. 385-395 ◽  
Author(s):  
Gerhard Maas ◽  
Robert Reinhard ◽  
Hans-Georg Herz
Keyword(s):  
Elevated Temperatures ◽  
Alder Reaction ◽  
Thermal Isomerization ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
Ring Enlargement ◽  
Diels Alder Reaction ◽  
Carbon Ring ◽  
Electrocyclic Reaction

2-Aminodienes, in which the enamine function is incorporated in a five-, six-, or seven-membered ring, react with dimethyl acetylenedicarboxylate in a sequence of [2+2] cycloaddition and electrocyclic ring-opening to form the two-carbon ring expanded unsaturated heterocycles, i.e., 3,4- dicarboxylate substituted 6,7-dihydro-1H-azepines 3, 8 and 21, 1,6,7,8-tetrahydroazocines 22, and 6,7,8,9-tetrahydro-1H-azonines 13. Similarly, 2-[(2-thienyl)ethynyl]-4,5,6,7-tetrahydro-1H-azepine 9 is converted into 2-[(2-thienyl)ethynyl]-6,7,8,9-1H-azonine-3,4-dicarboxylate 10 which was characterized by X-ray structure determination. The eight- and nine-membered azaheterocycles 22 and 13, which have not been isolated, undergo thermal isomerization at elevated temperatures. Thus, ring contraction by a 6π-electrocyclic reaction takes place for N-methyl substituted azonine 13, while the N-allyl moiety of azocines 22 engages in an intramolecular Diels-Alder reaction or a 1,7- electrocyclization reaction

Cycloaddition Reactions of 3-Dimethylamino-1-methyl-1,2,4-triazinium-5-olates With Dimethyl Acetylenedicarboxylate

1995 ◽  
Vol 48 (6) ◽  
pp. 1175 ◽  
Author(s):  
RP Musgrave ◽  
NW Jacobsen ◽  
G Bourne ◽  
CHL Kennard ◽  
G Smith ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Single Crystal ◽  
Cycloaddition Reactions ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
Structure Determinations ◽  
Mechanism Of The Reaction

The cycloaddition reactions of some 3-dimethylamino-1-methyl-1,2,4-triazinium-5-olates (1) with dimethyl acetylenedicarboxylate ( dmad ) were studied. The products in all cases were found tobe dimethyl 4-dimethylamino-1-methyl-6-oxo-1,3a,6,6a-tetrahydropyrrolo[3,4-c]pyrazole-3,3a-dicarboxylate derivatives (2). The structure determinations were carried out by 1H and 13C n.m.r. and mass spectrometry, and for one derivative by single-crystal X-ray diffractometry. The mechanism of the reaction is also discussed.

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