Stereo- and Regiocontrolled Syntheses of Exomethylenic Cyclohexane Beta-Amino Acid Derivatives

Cyclohexane analogues of the antifungal icofungipen [(1R,2S)-2-amino-4-methylenecy clopentanecarboxylic acid] were selectively synthesized from unsaturated bicyclic beta-lactams by transformation of the ring olefinic bond through three different regio- and stereocontrolled hydroxylation techniques, followed by hydroxy group oxidation and oxo-methylene interconversion with a phosphorane. Starting from an enantiomerically pure bicyclic beta-lactam obtained by enzymatic resolution of the racemic compound, an enantiodivergent procedure led to the preparation of both dextro- and levorotatory cyclohexane analogues of icofungipen

A de novo Synthetic Route to 1,2,3,4-Tetrahydroisoquinoline Derivatives

A novel synthetic approach was developed for the construction of the 1,2,3,4-tetrahydroisoquinoline framework possessing varied functions. The synthetic strategy was based on oxidative ring opening of some indene derivatives through their C=C bond, followed by double reductive amination of the dicarbonyl intermediates with various primary alkyl- or fluoroalkylamines

Stereocontrolled Synthesis of Functionalized Azaheterocycles from Carbocycles through Oxidative Ring Opening/Reductive Ring Closing Protocols

Fluorine-containing organic scaffolds are of significant interest in medicinal chemistry. The incorporation of fluorine into biomolecules can lead to remarkable changes in their physical, chemical, and biological properties. There are already many drugs on the market, which contain at least one fluorine atom. Saturated functionalized azaheterocycles as bioactive substances have gained increasing attention in pharmaceutical chemistry. Due to the high biorelevance of organofluorine molecules and the importance of N-heterocyclic compounds, selective stereocontrolled procedures to the access of new fluorine-containing saturated N-heterocycles are considered to be a hot research topic. This account summarizes the synthesis of functionalized and fluorine-containing saturated azaheterocycles starting from functionalized cycloalkenes and based on oxidative ring cleavage of diol intermediates followed by ring expansion with reductive amination

Stereocontrolled Synthesis of Functionalized Azaheterocycles from Carbocycles through Oxidative Ring Opening/Reductive Ring Closing Protocols

Fluorine-containing organic scaffolds are of significant interest in medicinal chemistry. The incorporation of fluorine into biomolecules can lead to remarkable changes in their physical, chemical, and biological properties. There are already many drugs on the market, which contain at least one fluorine atom. Saturated functionalized azaheterocycles as bioactive substances have gained increasing attention in pharmaceutical chemistry. Due to the high biorelevance of organofluorine molecules and the importance of N-heterocyclic compounds, selective stereocontrolled procedures to the access of new fluorine-containing saturated N-heterocycles are considered to be a hot research topic. This account summarizes the synthesis of functionalized and fluorine-containing saturated azaheterocycles starting from functionalized cycloalkenes and based on oxidative ring cleavage of diol intermediates followed by ring expansion with reductive amination

Functionalized Dialdehydes as Promising Scaffolds for Access to Heterocycles and beta-Amino Acids: Synthesis of Fluorinated Piperidine and Azepane Derivatives

Functionalized dialdehydes are considered important substrates that can be transformed into various substituted heterocyclic, alicyclic, and polysubstituted compounds. Here, we report a robust stereocontrolled procedure for the synthesis of novel functionalized trifluoromethyl-containing piperidine and azepane derivatives, based on oxidative ring cleavage of the C=C bond of diversely substituted cycloalkenes, followed by reductive ring closure of the diformyl intermediates in the presence of fluorine-containing amines

Stereo- and Regiocontrolled Syntheses of Exomethylenic Cyclohexane β-Amino Acid Derivatives

Cyclohexane analogues of the antifungal icofungipen [(1R,2S)-2-amino-4-methylenecyclopentanecarboxylic acid] were selectively synthesized from unsaturated bicyclic β-lactams by transformation of the ring olefinic bond through three different regio- and stereocontrolled hydroxylation techniques, followed by hydroxy group oxidation and oxo-methylene interconversion with a phosphorane. Starting from an enantiomerically pure bicyclic β-lactam obtained by enzymatic resolution of the racemic compound, an enantiodivergent procedure led to the preparation of both dextro- and levorotatory cyclohexane analogues of icofungipen