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Université de Neuchâtel

Photochemical Cycloadditions to 5,6-Dihydro-4-pyridones

Guerry, Philippe ; Neier, Reinhard

In: Chimia, 1987, vol. 41, no. 10, p. 341-342

5,6-Dihydro-4-pyridones (3a-3c) undergo photochemical [2 + 2]-cycloaddition with olefins activated by an electron withdrawing group. Alkyi substituted double bonds could only be brought to react in the intramolecular cases 3d and 3e.

Université de Neuchâtel

The chemical synthesis of porphobilinogen an important intermediate of the biosynthesis of the "pigments of life"

Bobal, Pavel ; Neier, Reinhard

In: Trends in Organic Chemistry, 1997, vol. 6, p. 125-144

Porphobilinogen is the second dedicated intermediate in the biosynthesis of «pigments of life». Only very few alkylpyrroles have been isolated from natural sources so far. The absence of stabilising substituents confers to porphobilinogen a high reactivity. The chemical synthesis of porphobilinogen had to take its sensitivity into account. The published synthesis of this unusual pyrrole are...

Université de Neuchâtel

L’histoire de l’Institut de chimie de l’Université de Neuchâtel entre 1875 et 1962

Vanbergue, Chantal ; Neier, Reinhard

In: Bulletin de la Société Neuchâteloise des Sciences Naturelles, 2001, vol. 124, p. 161-178

L'histoire des institutions, et surtout des instituts académiques, est étroitement liée aux professeurs qui y enseignent. L'Institut de chimie de l'Université de Neuchâtel n'est pas une exception à cette règle. C'est en la suivant que nous essaierons de retracer l'histoire de l'enseignement et de la recherche en chimie à Neuchâtel, à l'aide des biographies des professeurs de chimie. Les...

Université de Neuchâtel

La préparation des nitriles à partir des chlorures d'acide

Chaperon, André ; Fernandez, Maria ; Bobillier Neier, Christiane ; Vilches, Maria Theresa ; Neier, Reinhard

In: Bulletin de la Société Neuchâteloise des Sciences Naturelles, 1996, vol. 119, p. 111-121

Eine neuartige Methode um Saurechloride in einer Eintopf-Reaktion in die entsprechenden Nitrile umzuwandein ist entwickelt worden. Die Reaktionsbedingungen fur diese Umwandiung, bei der Hexamethyldisilazan und Trimethyliodosilan als Reagenzien verwendet werden, wurden optimiert. 29-NMR Studien erlaubten es den Mechanismus teilweise aufzuklären.

Université de Neuchâtel

rac-Ethyl 2-bromo-2-[(3R,5R)-3-bromo-5-methyltetrahydrofuran-2-ylidene]acetate

Loiseau, François ; Neier, Reinhard ; Labat, Gael ; Stoeckli-Evans, Helen

In: Acta Crystallographica Section C, 2006, vol. 62, no. 11, p. o636-o638

In the title compound, C9H12Br2O3, a (tetrahydrofuran-2-ylidene)acetate, the double bond has the Z form. In the tetrahydrofuran group, the relative configuration of the Br atom in the 3-position and the methyl group in the 5-position is anti. The compound crystallizes with two independent molecules per asymmetric unit and, in the crystal...

Université de Neuchâtel

rac-(R)-2-[(2R,5R)-5-Methyl­tetra­hydro­furan-2-yl]propanoic acid

Loiseau, François ; Neier, Reinhard ; Stoeckli-Evans, Helen

In: Acta Crystallographica Section E, 2006, vol. E, no. 62, p. o3407-o3409

In the crystal structure of the title compound, C8H14O3, the 2,5-tetra­hydro­furan ring junction is cis. The relative configuration of position 2 in the propanoic acid group was found to be the same as that in positions 2 and 5 in the tetra­hydro­furan ring. In the crystal structure, symmetry-related mol­ecules are linked by O***HO hydrogen bonds to form...

Université de Neuchâtel

Synthesis of Substituted 1-Thiocyanatobutadienes and their Application in a Diels-Alder/[3,3] Sigmatropic Rearrangement Tandem Reaction

Lanaspèze, Sébastien ; Neier, Reinhard

In: Monatshefte für Chemie / Chemical Monthly, 2005, vol. 136, no. 4, p. 597-607

The retrosynthetic analysis of Ibogamine, a natural psychotropic alkaloid with exceptional anti-addictive properties found in both enantiomeric forms, requires an efficient access to a racemic cyclohexene. This cyclohexene can be obtained via the sequence Diels-Alder/[3,3] sigmatropic rearrangement reaction starting from substituted 1-thiocyanatobutadienes. An efficient synthesis of the...

Université de Neuchâtel

Amino-Claisen Rearrangements and Diels-Alder Reactions of Ketene N,O-Acetals: Reactivity Studies. On the Way to a Novel Tandem Process?

Neuschütz, Klaus ; Simone, Jean-Mary ; Thyrann, Thomas ; Neier, Reinhard

In: Helvetica Chimica Acta, 2000, vol. 83, no. 10, p. 2712 - 2737

We report the synthesis of N-benzyl-N-[(E)-buta-1,3-dienyl]propanamide (6) and its corresponding O-silyl-substituted ketene N,O-acetal 7 and their Diels-Alder reaction. Propanamide 6 reacted smoothly, whereas the yield obtained from 7 was low, probably due to polymerization of the dienophile induced by electron transfer. The ketene...

Université de Neuchâtel

Malonylation/Decarbalkoxylation of Furan Derivatives as Key Steps for the Preparation of Nonactic Acid Derivatives. Part II [1]

Simone, Jean-Mary ; Loiseau, François ; Carcache, David ; Bobal, Pavel ; Jeanneret-Gris, Julie ; Neier, Reinhard

In: Monatshefte für Chemie / Chemical Monthly, 2007, vol. 138, no. 2, p. 141-147

A malonylation/decarbalkoxylation sequence from 2-substituted furans was investigated in view of developing a scalable synthesis of hydrophobic nonactic acid analogues.

Université de Neuchâtel

Electrochemiluminescent hybridization chip with electric field aided mismatch discrimination

Spehar-Deleze, Anna-Maria ; Schmidt, Laurette ; Neier, Reinhard ; Kulmala, Sakari ; de Rooij, Nico ; Koudelka-Hep, Milena

In: Biosensors and Bioelectronics, 2006, vol. 22, no. 5, p. 722-729

This paper describes a heterogeneous DNA-hybridization assay based on electrochemiluminescence (ECL) detection on gold electrodes. Short, 15-mer oligonucleotides were conjugated with a synthesized electrochemiluminescent label, bis(2,2′-bipyridine)-5-isothiocyanato-1,10-phenanthroline ruthenium(II) at the amino-modified 5′-end. Gold electrodes were derivatized with 15-mer oligonucleotide...