The site-selective reaction of a multi-functional linear molecule requires a suitable catalyst possessing both a uniform narrow channel to limit the molecule rotation and a designed active site in the channel.Recently,nanoparticles(NPs)have been incorporated in metal–organic frameworks(MOFs)with the tailorable porosity and ordered nanochannel,which makes these materials(NPs/MOFs)highly promising candidates as catalytic nanoreactor in the field of heterogeneous catalysis.However,most of the catalytic reactions employing NPs/MOFs as catalyst focused on the size-or shape-selectivity of reactants and products,while the reaction of site-selectivity in one molecule remains a challenge,in spite of the significance of site-selectivity for the formation of a single product from multifunctional groups in the fields of catalysis and chemical synthesis.Herein,we developed a simple heterogeneous catalyst based on NPs/MOFs that exhibited site-selectivity for the oxidation of diols by restricting the random rotation of the molecule in the limited space of the MOF channel,thereby protecting the middle functional group via steric hindrance.This strategy is not limited to the oxidation of diols,but can be extended to the site-selective reaction of many similar multi-functional linear molecules,such as the reduction of alkadienes and unsaturated aldehydes.