Photocatalytic C(sp3)-O/N Cross-Couplings by NaI-PPh3/CuBr Cooperative Catalysis: Computational Design and Experimental Verification

Photocatalytic coupling reactions have developed rapidly in the field of organic synthesis. However, highly efficient, broad-spectrum, low-cost, and energy-saving catalytic systems are urgently needed. Herein a desirable alternative combining NaI-PPh3 photoredox catalyst and Cu(I) catalyst was theoretically designed and evaluated from photophysical processes and potential energy surfaces. This metallaphotoredox catalysis could achieve C(sp(3))-O/N cross-couplings of alkyl N-hydroxyphthalimide esters with phenols/secondary amines via a radical mechanism merging photoexcited radical decarboxylation and a low-valent Cu-I-Cu-II-Cu-I cycle. More importantly, a series of target reactions can be realized with high yield (>= 90%) at room temperature under only irradiation with 10 W blue light-emitting diodes for 4 h without additional precious photocatalysts, which is mild, convenient, and environmentally friendly. Thus, this synthesis strategy combining theory and experiment can provide a facile and economic route and a clear mechanistic understanding for C(sp(3))-X cross-coupling reactions.

Automated summary

Photocatalytic coupling reactions have rapidly developed in the field of organic synthesis. A novel metallaphotoredox catalysis utilizing a NaI-PPh3 photoredox catalyst and Cu(I) catalyst was designed and evaluated, achieving high yields of C(sp(3))-O/N cross-couplings of alkyl N-hydroxyphthalimide esters with phenols/secondary amines under mild conditions with only blue light irradiation. This strategy provides a facile and economic route for C(sp(3))-X cross-coupling reactions while also offering a clear mechanistic understanding.