Saturated bicycles are becoming ever more important in the design and development of new pharmaceuticals. Here a new strategy for the synthesis of bicyclo[2.1.1]hexanes is described. These bicycles are significant because they have defined exit vectors, yet many substitution patterns are underexplored as building blocks. The process involves sensitization of a bicyclo[1.1.0]butane followed by cycloaddition with an alkene. The scope and mechanistic details of the method are discussed.

This work reports on the generation of a graphiteconjugated diimine macrocyclic Co catalyst (GCC-CoDIM) that is assembled at o-quinone edge defects on graphitic carbon electrodes. X-ray photoelectron spectroscopy and X-ray absorption spectroscopy confirm the existence of a new Co surface species with a coordination environment that is the same as that of the molecular analogue, [Co(DIM)Br 2 ] + . GCC-CoDIM selectively reduces nitrite to ammonium with quantitative Faradaic efficiency and at a rate that approaches enzymatic catalysis. Preliminary mechanistic investigations suggest that the increased rate is accompanied by a change in mechanism from the molecular analogue. These results provide a template for creating macrocycle-based electrocatalysts based on first-row transition metals conjugated to an extreme redox-active ligand.

A new strategy for the synthesis of highly versatile cyclobutylboronates via the photosensitized [2 +2]-cycloaddition of alkenylboronates and alkenes is presented. The process is mechanistically different from other processes in that energy transfer occurs with the alkenylboronate as opposed to the other alkene. This strategy allows for the synthesis of an array of diverse cyclobutylboronates. The conversion of these adducts to other compounds as well as their utility in the synthesis of melicodenine C is demonstrated.

We report an iron-based graphite-conjugated electrocatalyst (GCC-FeDIM) that combines the well-defined nature of homogeneous molecular electrocatalysts with the robustness of a heterogeneous electrode. A suite of spectroscopic methods, supported by the results of DFT calculations, reveals that the electrode surface is functionalized by high spin (S = 5/2) Fe­(III) ions in an FeN4Cl2 coordination environment. The chloride ions are hydrolyzed in aqueous solution, with the resulting cyclic voltammogram revealing a Gaussian-shaped wave assigned to 1H+/1e‑ reduction of surface Fe­(III)–OH surface. A catalytic wave is observed in the presence of NO3 –, with an onset potential of −1.1 V vs SCE. At pH 6.0, GCC-FeDIM rapidly reduces NO3 – to ammonium and nitrite with 88 and 6% Faradaic efficiency, respectively. Mechanistic studies, including in situ X-ray absorption spectroscopy, suggest that electrocatalytic NO3 – reduction involves an iron nitrosyl intermediate. The Fe–N bond length (1.65 Å) is similar to that observed in {Fe­(NO)}6 complexes, which is supported by the results of DFT calculations.

The mercury working electrode promotes electrocatalytic nitrate reduction by trans-Cr(cyclam)Cl2+.