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RESEARCH PRODUCT

Synthesis, reactions and structural features of monofluorinated cyclopropanecarboxylates

Günter HaufeRoland FröhlichKari RissanenOliver MeyerThomas C. Rosen

subject

CyclopropanationOrganic ChemistryIntermolecular forceEnantioselective synthesisSolid-stateOxazolineBiochemistryMedicinal chemistryInorganic Chemistrychemistry.chemical_compoundEnantiopure drugchemistryEnvironmental ChemistryMethanolPhysical and Theoretical ChemistryEnantiomeric excess

description

Abstract Monofluorinated cyclopropanecarboxylates are available in racemic or optically active form by transition metal-catalyzed reactions of vinylfluorides with diazoacetates. From α-fluorostyrene and tert-butyl diazoacetate in the presence of 2 mol% of an enantiopure bis(oxazoline) copper complex, a 81:19 mixture of tert-butyl trans- and cis-2-fluoro-2-phenylcyclopropanecarboxylates was obtained with high enantiomeric excess (ee) of 93 or 89%, respectively. The corresponding racemic ethylesters were used as starting materials for the synthesis of carboxamides, of the cis- and trans-isomers of analogues of tranylcypromine, an anti-depressive drug and several of its homologous fluorinated cyclopropylmethyl and cyclopropylethyl amines. Corresponding enantiopure cyclopropylmethanols and several of their derivatives were synthesized also. Solid state structures of a selection of these compounds were examined by X-ray crystallography. Particularly, the cis-configurated fluorinated phenylcyclopropane derivatives showed extremely close intermolecular CH⋯FC contacts. The shortest of such distances (2.17 A) was found in the N-(4-bromophenyl)carbamate of (1S,2R)-(2-fluoro-2-phenylcyclopropyl)methanol.

https://doi.org/10.1016/s0022-1139(02)00040-4