Chemoselective formation of cyclo-aliphatic and cyclo-olefinic 1,3-diols via pressure hydrogenation of potentially biobased platform molecules using Knölker-type catalysts

The hydrogenative conversions of the biobased platform molecules 4-hydroxycyclopent-2-enone and cyclopentane-1,3-dione to their corresponding 1,3-diols are established using a pre-activated Knölker-type iron catalyst. The catalyst exhibits a high selectivity for ketone reduction, and does not induce dehydration. Moreover, by using different substituents of the ligand, the cis-trans ratio of the products can be affected substantially. A decent compatibility of this catalytic system with various structurally related substrates is demonstrated.