Henrik Stephensen

Solid-phase synthesis of N-hydroxyindoles and benzo[c]isoxazoles by C-arylation of substituted acetonitriles and 1,3-dicarbonyl compounds with polystyrene-bound aryl fluorides

The reaction of different carbon nucleophiles with resin-bound 4-fluoro-3-nitrobenzoic acid and the chemistry of the resulting products has been investigated. Treatment of Wang resin bound 4-fluoro-3-nitrobenzoic acid with 1,3-dicarbonyl compounds or acceptor-substituted acetonitriles, followed by reduction of the nitro group and cleavage from the support, led to substituted 1-hydroxy-6-indolecarboxylic acids. Treatment of polystyrene-bound 4-fluoro-3-nitrobenzoic acid amides with arylacetonitriles led to 4-aroyl-3-nitrobenzoic acid derivatives, which upon reduction with tin(II) chloride yielded benzo[c]isoxazoles.

Sequential Nucleophilic Substitution: A Powerful Strategy for the Solid-Phase Production of Diverse Compound Libraries.

Polyfunctionalized, unprotected reagents (e.g. amines and thiols) can be used in the production of highly diverse compound libraries by performing sequential nucleophilic substitutions on support-bound polyelectrophiles (see scheme). The procedure reported here enables the efficient preparation of new beta-alanine derivatives which are suitable for lead discovery. E*=polyelectrophile, *=solid support.

Intermolecular N-alkylation of amines under conditions of the Mitsunobu reaction: a new solid-phase synthesis of tertiary benzylamines

Abstract Support-bound secondary aliphatic amines can be N -benzylated with benzyl alcohols under the standard conditions of the Mitsunobu reaction if the amine is converted into the corresponding ammonium iodide salt prior to Mitsunobu reaction.

Direct conversion of Fmoc-protected amines into O-alkyl carbamates by the Mitsunobu reaction: a practical strategy for the solid-phase synthesis of carbamates

Abstract Support-bound, Fmoc-protected amines react with aliphatic alcohols in the presence of ADDP, PBu 3 , and DIPEA to yield O -alkyl carbamates. The reaction presumably proceeds via O -alkylation of an intermediate carbamate anion.