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 ◽  
...  

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.

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 ◽  
...  

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.


1992 ◽  
Vol 45 (7) ◽  
pp. 1155 ◽  
Author(s):  
GA Bowmaker ◽  
D Camp ◽  
RD Hart ◽  
PC Healy ◽  
BW Skelton ◽  
...  

The 1 : 1 complexes of the substituted triphenylphosphine ligands mesityldiphenylphosphine and dimesitylphenylphosphine with copper(1) chloride, bromide and iodide have been the subject of single-crystal X-ray structure determinations at 295 K. All six complexes crystallize as air-stable dimeric molecules, [(PPh2Mes)CuX]2 and [ (PPhMes2)CUX]2 with each copper atom in a distorted trigonal PCuX2. coordination environment. Crystals of [(PPh2Mes)CuCl]2 (1) are monoclinic, P21/n, a 9.961(3), b 18.687(6), c 11.009(7) Ǻ, β 114.63(4)°; R was 0.049 for 2450 'observed' reflections. [(PPh2Mes)CuBrI2 (2) is monoclinic, P21/n, a 9.939(2), b 18.832(6), c 11.238(6) Ǻ, β 115.36(3)°; R was 0.046 for 1803 'observed' reflections. [(PPh2Mes)CuI]2.4/3 C6H6 (3) is rhornbohedral, R3, a 36.877(8), c 9.047(5) A; R was 0.039 for 2537 'observed' reflections. Crystals of [(PPhMes2)CuCl]2.2MeCN (4) are triclinic, Pi, a 15.783(7), b 9.570(4), c 8.914(4) Ǻ, α 72.43(3), β 76.37(3), γ 74.03(3)°; R was 0.045 for 3341 'observed' reflections. [(PPhMes2)CuBr]2.3C6H6 (5) is monoclinic, C2/c, a 9.694(6), b 30.15(2), c 20.66(2) Ǻ, β 98.00(7)°; R was 0.047 for 2117 'observed' reflections. [(PPhMes2)CuI]2.2MeCN (6) is orthorhombic, PP1nb, a 11.694(8), b 14.77(1), c 29.76(3) Ǻ; R was 0.049 for 3447 'observed' reflections. Cu-P bond lengths are: 2.196(2) A (1); 2.198(3) Ǻ (2); 2.222(5) and 2.226(5) Ǻ (3); 2.202(1) Ǻ (4); 2.197(3) A (5); 2.201(4) and 2.264(5) Ǻ (6). The geometries of the LCuX2 and CuX2Cu units are compared with data reported for other monomeric and dimeric compounds for both phosphorus- and nitrogen-based ligands L.


1990 ◽  
Vol 43 (10) ◽  
pp. 1657 ◽  
Author(s):  
LM Engelhardt ◽  
BW Skelton ◽  
RV Stick ◽  
DMG Tilbrook ◽  
AH White

A variety of approaches towards the synthesis of lincosamine, a derived portion of the antibiotic lincomycin , are reported. Initial approaches involved the intramolecular delivery of a nitrogen atom ( trichloroacetimidate , trichloroacetylcarbamate , carbamate, 2-amino-2- phenylacetate ) attached to O4 onto C6 of a 6,7-anhydrooctoside. Later approaches, albeit more direct but again largely unsuccessful, involved the Sharpless titanium(IV)-mediated nucleophilic opening of a suitable 6,7-anhydrooctose, and the Sharpless oxyamination and the aziridination of suitable octenoses . As an aid to the structure elucidation of several compounds encountered in this work, single-crystal X-ray structure determinations are reported for methyl 6,7-anhydro-2,3-di-O-benzyl-8-deoxy-α-D-threo-D-galacto-octopyranoside , methyl 6,7-anhydro-2,3-di-O-benzyl-8-deoxy-α-D-threo-D-gluco-octopyranoside and 7-azido-7-deoxy-1,2:3,4-di-O-isopropylidene-β-L-erythro-Dgalacto-octose.


2020 ◽  
Author(s):  
Viktoria Leonhardt ◽  
Stefanie Fimmel ◽  
Ana-Maria Krause ◽  
Florian Beuerle

<div><div><div><p>A trigonal-bipyramidal covalent organic cage compound serves as an efficient host to form stable 1:1-complexes with C60 and C70. Fullerene encapsulation has been comprehensively studied by NMR and UV/Vis spectroscopy, mass spectrometry as well as single-crystal X-ray diffraction. Exohedral functionalization of encapsulated C60 via threefold Prato reaction revealed high selectivity for the symmetry-matched all-trans-3 addition pattern.</p></div></div></div>


1975 ◽  
Vol 30 (5-6) ◽  
pp. 462-464 ◽  
Author(s):  
R. Haegele ◽  
W. Verscharen ◽  
D. Babel

The parameters of complete X-ray structure determinations are given for the fluoridesRb2NaFeF6 and Rb2KFeF6 (cubic), Cs2NaCrF6 and Cs2NaFeF6 (hexagonal-rhom-bohedral) and Cs2LiGaF6 (hexagonal). Space group and lattice constants of the monoclinic cyanides Cs2BFe(CN)6 (B = Na, K, Rb) are reported as well.


1995 ◽  
Vol 48 (9) ◽  
pp. 1511 ◽  
Author(s):  
SG Pyne ◽  
J Safaei-G ◽  
BW Skelton ◽  
AH White

The 1,3-dipolar cycloaddition reactions of the chiral oxazolidinone (1) and nitrones are highly regioselective and only 5,5-disubstituted isoxazolidine adducts are formed. These reactions occur under equilibrating conditions to give the more stable adducts that result from addition to the exocyclic methylene of (1) from the sterically more hindered π-face. The endo adducts are generally thermodynamically favoured. In one case the novel azetidine (21) was formed from the treatment of the adduct (4a) with palladium hydroxide on carbon under a hydrogen atmosphere. The major adducts from the reaction of (1) and nitrile oxides (16a,b) had the expected stereochemistry, addition of the 1,3-dipole having occurred from the less hindered π-face of the exocyclic methylene of (1). The stereochemistry of many of these products has been elucidated by single-crystal X-ray structural determinations.


1979 ◽  
Vol 32 (9) ◽  
pp. 1931 ◽  
Author(s):  
H Becker ◽  
K Gustafsson ◽  
CL Raston ◽  
AH White

Single-crystal X-ray diffraction structure determinations are reported for three reaction products and photoisomers formed from reactions between an o-diphenoquinone valence isomer and primary and secondary amines, namely: 3,5-di-t-butyl-7-(3,5-di-t-butyl-2-hydroxyphenyl)-1-methyl-2,3-dihydro-1H-azepin-2-one (8; R1 = R2 = But, R3 = Me), its photochemical isomerization product 4,6-di-t-butyl-1-(3,5-di-t-butyl-2-hydroxyphenyl)-2-methyl-2-azabicyclo[3,2,0]hept-6-en-3-one (9; R1 = R2 = But, R3 = Me) and 4',5,7-tri-t-butyl-3'-(2,2-dimethylpropionyl)-1'-methylspiro[benzofuran-3(2H)-2'- pyrrolidinel-2,5'-dione (12; R1 = R2 = But, R3 = Me).


2015 ◽  
Vol 69 (7) ◽  
Author(s):  
Alaa A. Hassan ◽  
Fathy F. Abdel-Latif ◽  
Mohamed Abdel Aziz ◽  
Sara M. Mostafa ◽  
Stefan Bräse ◽  
...  

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.


2016 ◽  
Vol 71 (3) ◽  
pp. 231-239 ◽  
Author(s):  
Roumaissa Belguedj ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Ali Belfaitah ◽  
Aissa Chibani ◽  
...  

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.


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