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Nanocatalysis is swiftly mounting in various catalyzed organic reactions. Nowadays a wide variety of nano sized species such as nanoparticles or nanocomposites are effectively employed as catalyst. Conventionally noble metals such as Pt, Pd, Rh and Au are used in various heterogeneous catalytic reductions in organic chemistry. Heterogeneous hydrogenation catalysis is highly desirable since in this stage the important enantio-differentiating step is happening at the metal surface. In this review, we try to underscore the recent development of using the traditional noble metals in their nano forms as nanocatalysts in the reduction of nitroarenes such as 4-nitrophenol (4-NP) and related compounds to their corresponding amino derivatives.

Three C 3 symmetric macrolactams were very efficiently cyclized from their linear precursors. Adequately located substituents are responsible for the enhancement of reactivity that is not observed in the unsubstituted parent. DFT calculations show that the properly folded cyclization precursor, the reactive conformer, is more populated than other conformers, leading to a decrease of free energy of activation. The crystal structure of the ring substituted with three very bulky esters indicates that tubular stacking is preserved.

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