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Stoeckli-Evans, Helen
Nom
Stoeckli-Evans, Helen
Affiliation principale
Email
helen.stoeckli-evans@unine.ch
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Voici les éléments 1 - 10 sur 33
- PublicationMétadonnées seulementPreparation of N-alkylketene-N-butadienyl-N,O-silyl acetals(1996)
; The synthesis of a series of dienamides 5a-j using Oppolzer's method is described. Using Rathke's method the ketene N,O-silyl acetals 6a-j can be obtained in good yield from the corresponding dienamides. The ketene acetals are obtained free of base and free of salts. They are stable and can be stored at - 20 degrees C. The new dienes are useful reagents for tandem reactions. - PublicationMétadonnées seulementApplication of the novel tandem process Diels-Alder reaction/Ireland-Claisen rearrangement to the synthesis of rac-juvabione and rac-epijuvabione(2000-1-12)
; The novel tandem process Diels-Alder reaction/Ireland-Claisen rearrangement shows a high diastereoselectivity for the Ireland-Claisen rearrangement starting from the endo-product of the Diels-Alder reaction. Based on this mechanistic knowledge, the novel tandem process could be applied to the synthesis of rac-juvabione. - PublicationMétadonnées seulementrac-(R)-2-[(2R,5R)-5-Methyltetrahydrofuran-2-yl]propanoic acid(2006)
; In the crystal structure of rac-(R)-2-[(2R,5R)-5-methyltetrahydrofuran-2-yl]propanoic acid, C8H14O3, the 2,5-THF ring junction is cis. The relative configuration of position 2 in the propanoic acid group is the same as that in positions 2 and 5 in the THF ring. In the crystal structure, symmetry-related mols. are linked by O-H...O H bonds to form centrosym. dimers. Crystallog. data are given. [on SciFinder(R)] - PublicationMétadonnées seulement2,2'-(Propane-2,2-diyl)bis(1H-pyrrole)2,2'-(Propane-2,2-diyl)bis(1H-pyrrole), C11H14N2, crystd. with 2 independent mols. (A and B) in the asym. unit. The 2 mols. differ only slightly, with the pyrrole rings being inclined to 1 another at a dihedral angle of 87.67(8)° in mol. A and 88.09(7)° in mol. B. In the crystal, there are no classical H bonds, but the 2 pyrrole NH groups of 1 mol. are involved in N-H···? interactions with the pyrrole rings of the other mol. In this manner, a compact box-like arrangement of the 2 independent mols. is formed. Crystallog. data are given. [on SciFinder(R)]
- PublicationMétadonnées seulement4-Methoxybenzoyl-meso-octamethylcalix[2]pyrrolidino[2]pyrrole: an acyl chloride derivative of a partially reduced calix[4]pyrroleIn the title compd., C36H50N4O2, the two pyrrolidine rings have envelope conformations. The conformation of the macrocycle is stabilized by N-H···N H bonds and a C-H···N interaction. The benzoyl ring is inclined to an adjacent pyrrole ring by 6.76(9)°, with a centroid-to-centroid distance of 3.6285(10) Å. In the crystal, apart from a C-H···O and a C-H···? interaction, mols. are linked via an N-H···O H bond, giving helical chains propagating along [010]. Crystallog. data and at. coordinates are given. [on SciFinder(R)]
- PublicationMétadonnées seulementSynthesis and Reactions of 2-[1-Methyl-1-(pyrrolidin-2-yl)ethyl]-1H-pyrrole and Some Derivatives with Aldehydes: Chiral Structures Combining a Secondary-Amine Group with an 1H-Pyrrole Moiety as Excellent H-Bond Donor(2012)
; ; ; The synthesis of compd. I (R = H) and its derivs. I (R = CF3, CO2Me) combining a pyrrolidine ring with an 1H-pyrrole unit is described. Their attempted usability as organocatalysts was not successful. Reacting these simple pyrrolidine derivs. with (E)-cinnamaldehyde led to tricyclic products. The final, major products were the pyrroloindolizidine tricycles, e.g. II, obtained via the iminium ion reacting intramolecularly with the nucleophilic ?-position of the 1H-pyrrole moiety. [on SciFinder(R)] - PublicationMétadonnées seulement2,2'-[(2S*,6R*)-Piperidine-2,6-diyl]dipropan-2-olIn the title compd., C11H23NO2, the piperidine ring has a chair conformation. The two hydroxy H atoms are disordered over two positions with fixed occupancy ratios of 0.57:0.43 and 0.63:0.37. In the mol., there are two short N-H···O interactions. In the crystal, four symmetry-related mols. are linked by O-H···O H bonds to form a cage-like arrangement, centered about the point of intersection of three 2-fold axes. These cages stack along the [100] direction. Crystallog. data and at. coordinates are given. [on SciFinder(R)]
- PublicationMétadonnées seulementSynthesis, structure, and complexation properties of partially and completely reduced meso-octamethylporphyrinogens (calix[4]pyrroles)(2009)
; Calixpyrroles bind anions efficiently and can be transformed into transition-metal complexes only under forcing conditions. Reducing the macrocycle creates a ligand that easily forms classical Werner complexes with Cu, Ni, and Pd ions. The metal complexes present an array of four directed H bonds, which specifically bind the counterions. [on SciFinder(R)] - PublicationMétadonnées seulement4-Meth-oxy-benzoyl-meso-octa-methyl-calix[2]pyrrolidino[2]pyrrole: an acyl chloride derivative of a partially reduced calix[4]pyrroleIn the title compound, C(36)H(50)N(4)O(2), the two pyrrolidine rings have envelope conformations. The conformation of the macrocycle is stabilized by N-H(midline ellipsis)N hydrogen bonds and a C-H(midline ellipsis)N inter-action. The benzoyl ring is inclined to an adjacent pyrrole ring by 6.76 (9)°, with a centroid-to-centroid distance of 3.6285 (10) Å. In the crystal, apart from a C-H(midline ellipsis)O and a C-H(midline ellipsis)? inter-action, mol-ecules are linked via an N-H(midline ellipsis)O hydrogen bond, leading to the formation of helical chains propagating along [010].
- PublicationMétadonnées seulement1,4-Bis(hexyloxy)-2,5-diiodobenzene(2010)
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