- Azirine and Aziridine Chemistry
- Heterocyclic Chemistry
- Mechanistic Studies
- Peptides and Thiopeptides
- Photochemistry
- Ring Enlargement
- Selenium Containing Heterocycles
- Stereoselective Synthesis
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Research Topics
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The research interrests of H. Heimgartner
The research activities of H. Heimgartner range from photochemistry and mechanisms of organic reactions to the preparation of heterocyclic compounds and the synthesis and conformation of peptides.
At present, the main interest is directed towards studies of the reactivity of 3-amino-2H-azirines and their use in preparative organic chemistry. These strained three-membered heterocycles react with a variety of acidic compounds to give novel N-heterocycles by ring enlargement. It has been shown that the azirine is inserted in the new ring as an a-amino acid moiety.
The development of the azirine/oxazolone method as a general route for the introduction of a,a-disubstituted glycines into linear and cyclic peptides render the synthesis of model peptides with restricted conformations, as well as some naturally occurring membrane modifying peptaibols, possible. A convenient lactone formation via direct amide cyclization has been elaborated. With this new strategy, cyclic depsipeptides with potential ionophoric activities may be synthesized.
The synthesis of enantiomerically pure 3-amino-2H-azirines as synthons for chiral a,a-disubstituted glycines is a challenging goal of the present work. Addition reactions with the exocyclic C=S bond of 1,3-thiazole-5(4H)-thiones, especially their regioselectivity, are being studied in detail. With diazo compounds, thiocarbonyl ylides are formed as reactive intermediates. Similarly, addition of organic azides leads to the scarcely known imides and, via a novel sulfur-transfer reaction, to thiocarbonyl sulfides. The reactivities of these 1,3-dipoles with a central S-atom will be the subject of future investigations.
In recent years, new approaches to selenium containing heterocycles received attention. A research program was started to overcome the major drawbacks of the known routes to this class of compounds: instability and toxicity. New routes were found using the easily accessible and less toxic isoselenocyanates.
The Following Groups of Problems are under Investigation:
Synthesis of novel 3-amino-2H-azirines
- Synthons for enantiomerically pure alpha,alpha-disubstituted glycines
- Synthons for alpha,alpha-heterocyclic alpha-amino acids
- Dipeptide synthons
Use of aminoazirines in the synthesis of peptides and depsipeptides
- azirine/oxazolone-method
- Synthesis of peptaibols such as Trichotoxin, Trichovirin, Antiamoebin, Zervamicin
- Synthesis of oligopeptides containing alpha,alpha-heterocyclic a-amino acids
- Synthesis of cyclic peptides containing alpha,alpha-disubstituted glycines
- Synthesis of cyclic depsipeptides
Synthesis of endothiopeptides containing alpha,alpha-disubstituted glycines
- Synthesis of endothiooligopeptides
- Thiopeptide antibiotics with thiazole rings as produced by Streptomyces species
Synthesis of heterocycles using 3-amino-2H-azirines
- Cyclic oxosulfonamides
- Regioselectivity of ring enlargements
- 1,3-dipolar cycloadditions
- 1,3-dipoles with a central Sulfur atom
- Synthesis of 1,3-oxathiolanes
New approaches to selenium-containing heterocycles
- 1,3-Selenazoles
- 1,2,3-Selenadiazoles
- Fused heterocyclic selones
Research Projects as PDF-document (90 kB).
Addition reactions with 1,3-thiazole-5(4H)-thiones; Synthesis of spirocyclic and fused bicyclic sulfur heterocycles
H. Heimgartner: Phosphorus, Sulfur and Silicon 1991, 58, 281.
A Ring Enlargement Reaction Yielding 1,2,5-Benzothiadiazonin-6-one 1,1-Dioxide A. S. Orahovats, A. Linden, H. Heimgartner: Helv. Chim. Acta 1992, 75, 2515.
Synthesis of a novel heterospirocyclic 3-(N-methyl-N-phenylamino)-2H-azirine and its use as an amino-acid equivalent in the preparation of a model peptide
J. M. Villalgordo, H. Heimgartner: Tetrahedron 1993, 49 , 7215.
Umsetzung von Di(tert-butyl)- und Diphenyldiazomethan mit 1,3-Thiazol-5(4H)-thionen: Isolierung und Kristall-Struktur des primären Cycloadduktes
G. Mloston, M. Petit, A. Linden, H. Heimgartner: Helv. Chim. Acta 1994, 77, 435.
Novel Heterospirocyclic 3-Amino-2H-azirines as Synthons for Heterocyclic alpha-Amino Acids
C. Strässler, A. Linden, H. Heimgartner: Helv. Chim. Acta, 1997, 80, 1528.
Reactions of 2-Unsubstituted 1H-Imidazole 3-Oxides with Heterocumulenes and Dimethyl Acetylenedicarboxylate
G. Mloston, T. Gendek, H. Heimgartner: Tetrahedron 2000, 56, 5405.
New Optically Active 2H-Azirin-3-amines as Synthons for Enantiomerically Pure 2,2-Disubstituted Glycines
K.A. Brun, A. Linden, H. Heimgartner: Helv. Chim. Acta 2001, 84, 1756.
Synthesis of the Endothiopeptide BOC-Trp-Ile-Ala-Aib-Ile-Val[CSNH]Aib-Leu-Aib-Pro-OMe by a Variation of the 'Azirine/Oxazolone Method'
J. Lehmann, A. Linden, H. Heimgartner: Tetrahedron 1998, 54, 8721.
Synthesis of 16-Membered Cyclic Depsipeptides via Direct Amide Cyclization
K.N. Koch, A. Linden, H. Heimgartner: Helv. Chim. Acta 2000, 83, 233.
1,3-Oxazol-5(4H)-ones as Intermediates in the Formation of Macrolides, Cyclodepsipeptides and Cyclopeptides
H. Heimgartner, F.S. Arnhold, S.P. Fritschi, K.N. Koch, J.E.F. Magirius, A. Linden: J. Heterocycl. Chem. 1999, 36, 1539.
Ring Enlargement of Eight- and Nine-Membered Cyclic Sulfonamide Derivatives in Reactions with 3-Amino-2H-azirines
T.R. Mihova, A. Linden, H. Heimgartner: Heterocycles 1998, 49, 215.
Stereochemical Course of the Reaction between Thiocarbonyl Compounds and Oxiranes: Reaction with cis- and trans-2,3-Dimethyloxirane
M. Blagoev, A. Linden, H. Heimgartner: Helv. Chim. Acta 2000, 83, 3163.
1,3-Oxathiole and Thiirane Derivatives from the Reactions of Azibenzil and alpha-Diazo Amides with Thiocarbonyl Compounds
M. Kägi, A. Linden, G. Mloston, H. Heimgartner: Helv. Chim. Acta 1998, 81, 285.
Selenium-Containing Heterocycles from Isoselenocyanates: Synthesis of 1,3-Selenazoles from Phenylimidoyl Isoselenocyanates
Y. Zhou, A. Linden, H. Heimgartner: Helv. Chim. Acta 2000, 83, 1576.
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