Flexible Strategy for Differentially 3,5‐Disubstituted 4‐Oxypyridin‐2(1H)‐ones Based on Site‐Selective Pd‐Catalyzed Cross‐Coupling Reactions.

Abstract

The products are relevant for the preparation of various bioactive compounds. -(CONREAUX, D.; BOSSHARTH, E.; MONTEIRO, N.; DESBORDES, P.; VORS, J.-P.; BALME*, G.; Org. Lett. 9 (2007) 2, 271-274; Lab. Synth. Organomet. Mol. Bioact., Univ. Claude Bernard Lyon, F-69622 Villeurbanne, Fr.; Eng.) -R. Steudel 20-128

Synthetic Studies on FNC-RED and Its Analogues Containing an All syn-Cyclopentanetetrol Moiety

“…17,18 The selective stepwise bromination and iodination gave the desired coupling precursor 11 in high yield. 19 With the requisite coupling precursors in hand, we went on to investigate the palladium catalyzed coupling reaction between the cyclopentenone derivative and the hydroxy-2pyridinone core. Initially, we examined the Heck-type reaction between the cyclopentenone 5 and 4-hydroxy-2-pyridinone 11.…”

“…The Balme group developed the site-selective Suzuki coupling reaction of 3bromo-5-iodo-2-pyridone, resulting from the lower capability of the C−Br bond to oxidative addition to palladium than the C−I bond. 19 The Cho group and the Sarpong group reported that the regioselective Stille coupling reactions of 3,5-dibromo-2-pyrone depend on the reaction conditions. 21,22 All our initial attempts to carry out the Heck-type reaction failed to produce the desired coupling product in a reasonable yield.…”