scholarly journals Reactions of 5-cyano-1,4-diphenylpyridazino[4,5-a]indolizines with dimethyl acetylenedicarboxylate: regioselective formation of 1:2 Michael type adducts

1993 ◽  
Vol 71 (4) ◽  
pp. 529-533 ◽  
Author(s):  
Kiyoshi Matsumoto ◽  
Yukio Ikemi ◽  
Motoo Shiro ◽  
Takane Uchida ◽  
James William Lown
Keyword(s):  
Resonance Structure ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography ◽  
Michael Additions

Reactions of 5-cyano-1,4-diphenylpyridazino[4,5-a]indolizines with dimethyl acetylenedicarboxylate afforded the 1:2 adducts regioselectively and, unexpectedly, in a Michael fashion rather than in a 1,3-dipolar manner. The structure of the products was established by X-ray crystallography. Regiospecific formation of the observed product 3 can be explained by the higher nucleophilicity of the nitrogen at the 2 position than at the 3 position of the 5-cyano-1,4-diphenylpyridazino[4,5-a]indolizine 1 owing to the contribution of a resonance structure 5 to the hybrid. This favors two successive Michael additions to two equivalents of dimethyl acetylenedicarboxylate affording the observed 1:2 adducts 3.

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.

Applications of the ene reaction. Synthesis and properties of substituted α-methylene-γ-lactones

1981 ◽  
Vol 59 (2) ◽  
pp. 288-301 ◽  
Author(s):  
Alfred W. Hanson ◽  
Archibald W. McCulloch ◽  
A. Gavin McInnes
Keyword(s):  
Starting Material ◽  
Reaction Synthesis ◽  
Dimethyl Acetylenedicarboxylate ◽  
Ene Reaction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Nmr Data ◽  
Predominant Product ◽  
C Nmr

Substituted dimethyl 1,4-pentadiene-1,2-dicarboxylates (1 or 3) may be prepared by AlCl3-promoted or thermal ene reaction of olefins with dimethyl acetylenedicarboxylate. Lactonization of these adducts is catalyzed by acid. In the presence of 80% H2SO4 the predominant product (ca. 80%) is a (Z)-dihydro-3-carbomethoxymethylene-2(3H)-furanone (2 or 4). Cyclization with anhydrous HCl affords a mixture of products, the composition of which depends on the starting material; major products include the corresponding (E)- and δ-lactone isomers (6 and 7). Detailed 1H and 13C nmr data are reported for all compounds. The structures of the (E)-4,5,5-trimethyl-, (Z)-4,5,5-trimethyl-, and (Z)-4,4,5,5-tetramethyl furanone derivatives (6a, 2a, and 2b) have been established by X-ray crystallography. The properties of some of these lactones are discussed, as are possible methods of removal of the carbomethoxyl from 2.

Ritter Reactions. XIII Reactivity of Methyl Schiff Bases with Dimethyl Acetylenedicarboxylate and Mercaptoacetic Acid

1998 ◽  
Vol 51 (9) ◽  
pp. 799 ◽  
Author(s):  
Qinghong Lin ◽  
Djamal Djaidi ◽  
Roger Bishop ◽  
Donald C. Craig ◽  
Marcia L. Scudder
Keyword(s):  
Schiff Bases ◽  
New Products ◽  
Mercaptoacetic Acid ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography ◽  
Rearrangement Process ◽  
Ray Methods

Reactions of several methyl imines with dimethyl acetylenedicarboxylate and with mercaptoacetic acid have been studied to investigate further the capricious behaviour of this functionality. The 1 : 1 adduct of imine (1) and dimethyl acetylenedicarboxylate is confirmed as the pyrroloisoquinoline structure (7) by X-ray methods [C17H17NO5, P -1, a 9·037(2), b 9·276(2), c 10·033(2) Å, α 81·99(1), β 81·28(1), γ 64·9(2)°, Z 2, R 0·044]. New products from (2) and dimethyl acetylenedicarboxylate, the 1 : 1 adduct (10) which is readily converted into the known product (9), and the 1 : 2 adduct (12), are described. The structure of the last compound, which arises through a rearrangement process, was determined by X-ray crystallography [C27H36N2O9,P ca21, a 19· 083(4), b 15·217(3), c 9·669(2) Å, Z 4, R 0·038]. Methyl imines (1) and (4) undergo cyclocondensation with mercaptoacetic acid yielding thiazolidinone products but others are inert under similar conditions.

scholarly journals Utilization of 1-phenylimidazo[1,5-a]quinoline as partner in 1,4-dipolar cycloaddition reactions

2020 ◽  
Vol 75 (3) ◽  
pp. 259-267
Author(s):  
Areej M. Jaber ◽  
Jalal A. Zahra ◽  
Mustafa M. El-Abadelah ◽  
Salim S. Sabri ◽  
Monther A. Khanfar ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectral Data ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography

AbstractA Selected set of 2-(quinolin-2-yl)-1,3-oxazepino[7,6-b]indoles 4a–d and dihydroacenaphtho[1,2-f][1,3]oxazepine 5 have been prepared via 1,4-dipolar cycloaddition reaction involving 1-phenylimidazo[1,5-a]quinoline, dimethyl acetylenedicarboxylate, and N-(substituted)isatins or acenaphthoquinone. Structures of the new heterocycles 4a–d and 5 are supported by NMR and HRMS spectral data, and confirmed by single-crystal X-ray crystallography for 4c and 5.

Some 6,6-disubstituted 2,4-cyclohexadien-1-ones and the facial selectivity in their Diels–Alder reactions with dimethyl acetylenedicarboxylate

1989 ◽  
Vol 67 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Peter Yates ◽  
Anabela Gomes ◽  
D. Jean Burnell ◽  
Dong Dao Cong ◽  
Jeffery F. Sawyer
Keyword(s):  
Spectroscopic Method ◽  
Diels Alder ◽  
The Other ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
Product Ratio ◽  
X Ray Crystallography ◽  
Facial Selectivity ◽  
Chemical Correlation ◽  
The Individual

6,6-Disubstituted 2,4-cyclohexadien-1-ones can be prepared by dibromination–bisdehydrobromination of the corresponding 6,6-disubstituted 2,2-dibromocyclohexanones. Such dienes undergo Diels–Alder reactions with dimethyl acetylenedicarboxylate to give 3,3-disubstituted 5,6-di(methoxycarbonyl)bicyclo[2.2.2]octa-5,7-dien-2-ones; when the substituents at C-6 in the dienones are different, two diastereomers of the adducts are formed in a ratio dependent on the "facial selectivity" in the Diels–Alder reactions. For the cases where one of the 6-substituents is methyl and the other is methoxycarbonyl, acetoxymethyl, dibromomethyl, or dichloromethyl it has been established via X-ray crystallography and chemical correlation that the endo-3-methyl/exo-3-methyl product ratio is 3.0, 0.9, 8, and 6, respectively. The origin of these differences is discussed briefly and a spectroscopic method for the assignment of structures to the individual diastereomers is proposed. Keywords: Diels–Alderreactions, substituted 2,4-cyclohexadien-1-ones, facial selectivity, dimethyl acetylenedicarboxylate.

The Dimerization and Cyclotrimerization of Acetylenes Mediated by Phosphine Complexes of Cobalt(I), Rhodium(I), and Iridium(I).

1999 ◽  
Vol 52 (11) ◽  
pp. 1085 ◽  
Author(s):  
Leslie D. Field ◽  
Antony J. Ward ◽  
Peter Turner
Keyword(s):  
Metal Complexes ◽  
Stable Complex ◽  
Dimethyl Acetylenedicarboxylate ◽  
Crystal Data ◽  
Terminal Acetylene ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Phosphine Complexes ◽  
Benzene Solvate

The catalytic dimerization and cyclotrimerization of phenylacetylene, ethyl propiolate, and dimethyl acetylenedicarboxylate were studied by using the metal complexes [Co(PPh3)3Cl] (1), [Co(PPh3)2(CO)2Cl] (2), [Co(PMe3)3Cl] (3), [Co(PMe3)2(CO)2Cl] (4), [Rh(dppe)(CO)Cl] (5), [Rh(PPh2Me)2(CO)Cl] (6), [Ir(dppe)(CO)Br] (7), and [Ir(PPh2Me)2(CO)Cl] (8). For all complexes studied, with terminal acetylene substrates, there is competition between head-to-head dimerization to form 1,4-disubstituted butenynes and cyclotrimerization to form 1,3,5- or 1,2,4-trisubstituted benzenes. The metallocyclopentadiene [Ir(dppe)(CO)(L)Br] (L= 1,4- diethoxycarbonylbuta-1,3-diene-1,4-diyl) was formed in the reaction of diethyl acetylenedicarboxylate with [Ir(dppe)(CO)Br] (7), and this stable complex is a possible intermediate in the cyclotrimerization of the acetylene. The metallocyclopentadiene was fully characterized by X-ray crystallography. Crystal data for the benzene solvate of (33), C43H42BrIrO5P2 at 21°C: space group P21/c (No. 14), a 8.774(4), b 22.155(3), c 20.242(2) Å, β 92.46(2)˚, V 3931(1) Å3 , Z 4, No 4804, Nvar 469, R(F) 0.0411, Rw(F) 0.0483.

Synthesis of bis-thiazolidin-4-ones from N,N,N″-(1,ω-alkanediyl)bis(N″-organylthiourea) derivatives

2015 ◽  
Vol 70 (4) ◽  
pp. 243-248 ◽  
Author(s):  
Alaa A. Hassan ◽  
Kamal M.A. El-Shaieb ◽  
Amal S. Abd El-Aal ◽  
Stefan Bräse ◽  
Martin Nieger
Keyword(s):  
Single Crystal ◽  
Spectroscopic Data ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography ◽  
Elemental Analyses

AbstractA new series of (2Z,2′E)-dimethyl 2,2′-[(2Z,2′Z)-3,3′-(alkanediyl)bis(4-oxo-2-iminothiozolidin-3-yl-5-ylidene)]acetates has been synthesized by the reaction of N,N″-(1,ω-alkanediyl)bis(N′-organylthiourea) derivatives with dimethyl acetylenedicarboxylate. The structures were established by spectroscopic data, elemental analyses, and single crystal X-ray crystallography. A rationale for the formation of the products is presented.

Difference Fourier Analysis of Glucose Embedded and Frozen Hydrated Purple Membrane

1982 ◽  
Vol 40 ◽  
pp. 74-75
Author(s):  
Jules S. Jaffe ◽  
Robert M. Glaeser
Keyword(s):  
Purple Membrane ◽  
Data Set ◽  
High Resolution Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Fourier Techniques ◽  
Versus Protein ◽  
The Difference ◽  
Difference Fourier ◽  
Ideal Method

Although difference Fourier techniques are standard in X-ray crystallography it has only been very recently that electron crystallographers have been able to take advantage of this method. We have combined a high resolution data set for frozen glucose embedded Purple Membrane (PM) with a data set collected from PM prepared in the frozen hydrated state in order to visualize any differences in structure due to the different methods of preparation. The increased contrast between protein-ice versus protein-glucose may prove to be an advantage of the frozen hydrated technique for visualizing those parts of bacteriorhodopsin that are embedded in glucose. In addition, surface groups of the protein may be disordered in glucose and ordered in the frozen state. The sensitivity of the difference Fourier technique to small changes in structure provides an ideal method for testing this hypothesis.

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