THE ASYMMETRIC-SYNTHESIS OF CYCLOPENTANE DERIVATIVES BY PALLADIUM-CATALYZED COUPLING OF PROCHIRAL ALKYLBORON COMPOUNDS

Treatment of the prochiral triflate 2a with Pd-2(dba)(3). CHCl3, (S)-( R)-BPPFOAc and K2CO3, in THF at 40 degrees C, gave the cyclopentane de rivative 10 in 58% yield and in 28% ee after oxidative work-up and ben zoylation. Moreover, reaction of the prochiral triflate 2c with Pd-2(d ba)(3). CHCl3, (S)-(R)-PPFA and K2CO3, in THF at 40 degrees C, afforde d the cyclopentane derivative 3b, with a quaternary carbon center, in 42% yield and in 31% ee after oxidative work-up. (C) 1998 Elsevier Sci ence Ltd. All rights reserved.