The photoredox conversion of organic functional groups into useful products without the reliance on expensive transition metal-based catalysts has been a major challenge. Here we report the photocatalytic conversion of N-hydroxy-carbamates into N-hydroxy-oxazolidinones using simple metal organic frameworks (MOFs) such as MIL-125-NH2 and UiO-66-NH2 as catalysts in aerobic conditions, with efficiencies and yields comparable to those performed using ground state catalysts. Through sampling increasingly complex structures of carbamates, we found that MOFs induce diasteroselectivities similar to those obtained in solution, which is pivotal in synthesizing natural products and pharmaceuticals, and that the photo-conversion occurred on or near the surface of MOF particles. To provide better mechanistic interpretations on these observations, kinetics studies, quantum yield measurements, and the determination of the photogenerated reactive species were performed. The temperature dependency in the kinetic studies enabled us to identify the photo-redox process as the rate-limiting step of the reaction, a trend that is consistent with using non-porous heterogeneous catalysts like TiO2. The structural traits of the studied MOFs explain how porosity and light absorption can be tuned for better photocatalysts for achieving high yields and selectivities.

An asymmetric synthesis of carbocyclic spiroindoline by sequential Michael reaction and [3 + 2]-cycloaddition is described. This protocol demonstrates excellent enantio- and diastereoselectivity with broad functional group tolerance. A diverse range of spiroindolines were prepared by this approach, and the products served as ideal substrates for C2 derivatization.

A highly stereoselective and scalable synthesis of l-allo-enduracididine from hydroxyproline derivative is described. Pyrrolidine oxidation and reductive ring opening are the key steps in the synthesis. Compared to previously reported approaches, the current route affords l-allo-enduracididine in 10 steps from 3 in 31% overall yield with >50:1 diastereoselectivity.

Selective O-benzoylation of hydroxamic acids is achieved by the treatment of BPO and DABCO. Aliphatic alcohols are not reactive under these conditions. Various radical or oxidation sensitive functional groups are compatible with this protocol, and no anhydrous reagents or solvents are required for the high yields of the benzoylations.

The photoredox conversion of organic functional groups into useful products without the reliance on expensive transition metal-based catalysts has been a major challenge. Here we report the photocatalytic conversion of N-hydroxy-carbamates into N-hydroxy-oxazolidinones using simple metal organic frameworks (MOFs) such as MIL-125-NH2 and UiO-66-NH2 as catalysts in aerobic conditions, with efficiencies and yields comparable to those performed using ground state catalysts. Through sampling increasingly complex structures of carbamates, we found that MOFs induce diasteroselectivities similar to those obtained in solution, which is pivotal in synthesizing natural products and pharmaceuticals, and that the photo-conversion occurred on or near the surface of MOF particles. To provide better mechanistic interpretations on these observations, kinetics studies, quantum yield measurements, and the determination of the photogenerated reactive species were performed. The temperature dependency in the kinetic studies enabled us to identify the photo-redox process as the rate-limiting step of the reaction, a trend that is consistent with using non-porous heterogeneous catalysts like TiO2. The structural traits of the studied MOFs explain how porosity and light absorption can be tuned for better photocatalysts for achieving high yields and selectivities.