Reactions of Epoxides Derived From 2′-(3″-Methylbut-2″-enyl)trifluoroacetanilides

1990 ◽  
Vol 43 (3) ◽  
pp. 609 ◽  
Author(s):  
KD Raner ◽  
BW Skelton ◽  
AD Ward ◽  
AH White

The intramolecular nucleophilic ring opening of the epoxides derived from 2′-(3″-methylbut-2″-enyl) trifluoroacetanilides has been investigated under both acidic and basic conditions. Boron trifluoride caused rearrangement of the epoxides to a ketone but no cyclization. Potassium carbonate in methanol caused regiospecific opening of the epoxides and generated dihydroindole products. The formation of a five-membered ring was confirmed by a single-crystal X-ray study of one of the products. The epoxides hydrolysed very readily in acidic conditions; the structure of one of the diol products was confirmed by a single-crystal X-ray study.

1995 ◽  
Vol 50 (12) ◽  
pp. 1811-1817 ◽  
Author(s):  
Max Herberhold ◽  
Christian Köhler ◽  
Wolfgang Milius ◽  
Bernd Wrackmeyer

N,N′-Dialkyl sulfur diimides (1), R(NSN)R [R = Me (a), Et (b), nPr (c), nBu (d)] react with cyclic bis(amino)stannylenes such as 1,3-di-tert-butyl-4,4-dimethyl-1,3,4,2λ2-diazasilastannetedine (2) or 1,3-di-tert-butyl-4,4,5,5-tetramethyl-1,3,4,5,2λ2-diazadisilastannolidine (3) in a 2:1 ratio to give the new spiro-tin(IV) compounds 5a-d, 6b and 6c, built from the respective cyclic bis(amino)stannylene and a seven-membered ring in which the two sulfur diimide groups are coupled via a N-N bond and across the tin atom. A 1:1 adduct 4 is proposed as an intermediate which is the final product 4e in the case of R = tBu (1e). The products were characterized by multinuclear magnetic resonance (1H, 13C, 15N, 29Si, 119Sn NMR), and in the case of 5c the molecular structure was determined by single crystal X-ray structure analysis [monoclinic, space group C2/c ; a = 1504.1(3), b = 1393.3(3), c = 1688.6(3) pm; β = 115.71(3)°].


2007 ◽  
Vol 11 (01) ◽  
pp. 31-41 ◽  
Author(s):  
Yuliya V. Morozova ◽  
Dmitry V. Yashunsky ◽  
Zoya A. Starikova ◽  
Gelii V. Ponomarev

Base-assisted ring opening in 1,2-oxazinochlorin derivatives led selectively to the corresponding meso-cyanohydroxychlorin derivatives. The latter could then undergo acid-mediated carbocation formation followed by nucleophilic treatment to give different products, depending on the nature of the nucleophile reagent. Treatment of (E)- and/or (Z)-2-ethylidene-3-hydroxy-5-cyano-3,7,8,12,13,17,18-heptaethylchlorin nickel complex with a mixture of 5% trifluoroacetic acid and dichloromethane yielded a novel type porphyrin-porphyrin dimer with a condensed cyclohexane ring in an almost quantitative yield. The structure of this dimer was determined by single crystal X-ray analysis.


2001 ◽  
Vol 56 (8) ◽  
pp. 711-718 ◽  
Author(s):  
Stefan D. Nogai ◽  
Annette Schier ◽  
Hubert Schmidbaur

The four ternary gallium(III) chalcogenide halides GaEX with E = S, Se and X = Cl, Br can be prepared a) from the binary gallium(III) chalcogenides Ga2E3 and halides Ga2X6, b) from gallium(I) tetrahalogallates(III) GafGaX4] and the chalcogen E, and c) from gallium metal and the dichalcogen dihalides E2X2. The new method c) was shown to be the most convenient preparation. The products are readily soluble in pyridine to give trinuclear molecular complexes [GaEX·Py]3 which are not volatile without decomposition, but can be purified by crystallization. The structures have been determined by single crystal X-ray diffraction techniques. The two chlorides are isostructural and show twisted tub-form six-membered ring molecules with the pyridine donors in axial positions. The two bromides are also isostructural, but with the pyridine ligands in two axial and one equatorial positions


1981 ◽  
Vol 34 (10) ◽  
pp. 2243 ◽  
Author(s):  
SR Hall ◽  
S Nimgirawath ◽  
CL Raston ◽  
A Sittatrakul ◽  
S Thadaniti ◽  
...  

The crystal structure of zerumbone, C15H22O, extracted from the rhizomes of Zingiber zerumbet Smith, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.051 for 925 'observed' reflections. Crystals are monoclinic, space group P21/c, a 9.036(3), b 9.712(5), c 15.643(6) �, β 97.19(3)�, Z = 4. Although the molecule has no chiral centre, the presence of the three trans double bonds confers considerable distortion and rigidity on the eleven-membered ring and renders the whole molecule chiral and potentially resolvable.


IUCrData ◽  
2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Rui Li ◽  
Xin-E Duan ◽  
Wei Cao ◽  
Xue-Hong Wei

The title compound, C14H20N4Si2 or [(Apy)2(μ-SiMe)2], systematic name 2-[2,2,4,4-tetramethyl-3-(pyridin-2-yl)-1,3,2,4-diazadisiletidin-1-yl]pyridine, was obtained as a side product from the reaction of 2-amino-pyridine with LiBu n followed by the addition of Me2NMe2SiCl in hexane. The compound was characterized by single-crystal X-ray diffraction analysis and NMR spectroscopy. The title compound lies about an inversion center at the centroid of the cyclodisilazane ring. The four-membered Si2N2 core is strictly planar with the two pyridyl rings placed centrosymmetrically on either side of the Si2N2 plane and are almost coplanar with the central four-membered ring.


2021 ◽  
Vol 18 ◽  
Author(s):  
Mohammed M. Abadleh ◽  
Ahmad H. Abdullah ◽  
Jalal A. Zahra ◽  
Salim S. Sabri ◽  
Firas F. Awwadi ◽  
...  

: A set of triethylammonium 4-oxo-6-pyridinethiolate–1,3,4-thiadiazoline hybrids (3a-e) were prepared via the reaction of ethyl 2-chloro-6-cyclopropyl-3- nitro-4-oxothieno[2,3-b]pyridine- 5-carboxylate (2) with the appropriate thiobenzoyl- hydrazide (1a-e) in acetonitrile and triethylamine. These hybrids were readily converted, under neutral mild conditions, into the corresponding 4-hydroxy-6-thioxopyridine –thiadiazoline hybrids (5a-e). The structures of the latter set are supported by HRMS, 1H NMR and 13C NMR spectral data and further confirmed by single-crystal X-ray diffraction studies. Alkylation of these hybrids in the presence of triethylamine occurred exclusively at the 6-thioxosulfur, yielding the respective 6-sulfanyl derivatives (6a-c).


2015 ◽  
Vol 11 ◽  
pp. 1632-1638 ◽  
Author(s):  
Maximilian Koy ◽  
Hagen J Altmann ◽  
Benjamin Autenrieth ◽  
Wolfgang Frey ◽  
Michael R Buchmeiser

The novel dicationic metathesis catalyst [(RuCl2(H2ITapMe2)(=CH–2-(2-PrO)-C6H4))2+ (OTf−)2] (Ru-2, H2ITapMe2 = 1,3-bis(2’,6’-dimethyl-4’-trimethylammoniumphenyl)-4,5-dihydroimidazol-2-ylidene, OTf− = CF3SO3 −) based on a dicationic N-heterocyclic carbene (NHC) ligand was prepared. The reactivity was tested in ring opening metathesis polymerization (ROMP) under biphasic conditions using a nonpolar organic solvent (toluene) and the ionic liquid (IL) 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [BDMIM+][BF4 −]. The structure of Ru-2 was confirmed by single crystal X-ray analysis.


2018 ◽  
Vol 22 (07) ◽  
pp. 562-572
Author(s):  
Ruoshi Li ◽  
Matthias Zeller ◽  
Christian Brückner

We describe the oxidative ring opening of octaethyl-2-oxochlorin using two different oxidation methods, both providing a mixture of all possible regioisomeric products (8-[Formula: see text] through 8-[Formula: see text]. While isomers 8-[Formula: see text], 8-[Formula: see text], and 8-[Formula: see text] formed in isolable yields and relative ratios that varied with the oxidation method used, isomer 8-[Formula: see text] was invariably formed in trace amounts only. The three major products were spectroscopically characterized (IR, MS, 1D- and 2D NMR spectroscopy) and their configurations were deduced by NMR spectroscopy. The spectroscopic findings correlated well with the single crystal X-ray structure of the novel cleavage product 8-[Formula: see text] and the known compound of 8-[Formula: see text]. The work broadens the number of octaethylporphyrin-derived biliverdin derivatives available and presents a methodology of controlling the biliverdin backbone configuration by introduction of a [Formula: see text]-ketone functionality into select positions.


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