Omar Karam

A novel, facile route to beta-fluoroamines by hydrofluorination using superacid HF-SbF(5).

A range of unsaturated amines and sulfonamides were converted to beta-fluoro nitrogen analogues after hydrofluorination in superacid HF-SbF(5), based on the formation of highly reactive electrophilic intermediates.

Fluorinated pyrrolidines and piperidines incorporating tertiary benzenesulfonamide moieties are selective carbonic anhydrase II inhibitors.

Abstract A series of substituted pyrrolidines and piperidines were synthesized using superacid HF/SbF5 chemistry. Investigated as inhibitors of several human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms, i.e. the cytosolic hCA I and II as well as the tumor-associated transmembrane isoforms hCA IX and XII, these compounds showed a never yet reported selectivity toward the human carbonic anhydrase hCA II. In the tertiary benzenesulfonamide family, this class of inhibitors points out a new mechanism of action for human carbonic anhydrase II inhibition.

Nucleophilic para-fluorination of 4-alkylphenols by hypervalent iodine reagent and pyridinium polyhydrogen fluoride (PPHF) : a novel route to 4-fluorocyclohexa-2,5-dienones

Abstract Ipso-fluorination of 4-alkylphenols with C 6 H 5 -I(OCOCF 3 ) 2 -pyridinium polyhydrogen fluoride (PPHF) yields 4—fluorocyclohexa-2,5-dienones.

Synthesis of hydroindolenones and hydroquinolenones by hypervalent iodine oxidation of mono or bicyclic phenols

Abstract Methoxy or fluoro hydroindolenones and hydroquinolenones can be obtained by oxidation of the corresponding 4-substituted open-chain phenolds with C 6 H 5 I(OCOCF 3 ) 2 with methanol or pyridinium polyhydrogen fluoride followed by an intramolecular conjugate addition. The corresponding cyclo 2,5-hexadienones can be obtained directly by a similar oxidation of the bicyclic phenols.

Ipso-chlorination of 4-alkylphenols ethers a novel route to 4-chlorocyclohexa-2,5-dienones.

Abstract Selective chlorination of 4-alkylphenols ethers with SbF5/CH2Cl2 (CHCl3, CCl4) yields 4-chlorocyclohexa-2,5-dienones; no α-chlorination to a carbonyl group is observed in the reaction conditions.

An efficient synthesis of 6-hydroxymelatonin, a human metabolite of melatonin

Abstract A four-step synthesis of 6-hydroxymelatonin 5 , major human metabolite of melatonin 1 , is reported starting from melatonin. The synthesis involves in the keys steps a regioselective Friedel–Crafts acylation followed by a Baeyer–Villiger oxidation. The overall yield is 48%.