An efficient route for the synthesis of chiral conduritol-derivative carboxamides via palladium-catalyzed aminocarbonylation of bromocyclohexenetetraols

A family of chiral conduritol-derivative carboxamides was synthesized through palladium-catalyzed aminocarbonylation of diastereoisomeric bromocyclohexenetetraols, previously prepared through biotransformation of bromobenzene by mutant strains of Pseudomonas putida F39/D. The coupling reactions of bromocyclohexenetetraols with CO and different amines, such as tert-butylamine, aniline, and piperidine, were performed in the presence of in situ generated Pd(0)/PPh3 catalyst. The methodology was applied to the corresponding iodo-cyclohexenetetraol derivative, using (L)-alanine and (L)-valine methyl ethers as N-nucleophiles. The resulting carboxamides were obtained in highly chemoselective reactions, isolated, and fully characterized.