Organometallic B₁₂ compounds are unique metal complexes having a cobalt-carbon s-bond present in biological systems. Cleavage of the metal-organic σ-bond initiates many B₁₂ dependent enzymatic reactions. Based on unique properties of B₁₂ enzymes, many B₁₂-inspired reactions were developed.^1-3 Here we report the visible light-driven B₁₂inspired reaction for the synthesis of base chemicals from carbon tetrahalides as C1 building block. The hybrid catalyst, B₁₂-Mg²⁺-TiO₂, composed of the B₁₂ derivative and titanium oxide modified with magnesium ion (Mg²⁺-TiO₂) was synthesized for the visible light-driven catalytic reaction (Figure 1). Carbon tetrachloride (CCl₄) was converted to N,N-diethylurea by the B₁₂-Mg²⁺-TiO₂ catalyst under the visible light irradiation (l>420 nm) with diethylamine (Et₂NH) in air at room temperature. Valuable ureas are synthesized from CCl₄ under mild condition. This photochemical catalytic reaction was applied to the synthesis of asymmetric ureas, carbamates, and carbonate ester via carbamoyl chloride in the presence of corresponding nucleophiles, RNH₂, R₂NH, ROH. Furthermore, the reactions were applied to carbon tetrabromide (CBr₄) as substrate. Carbon tetrabromide is a commercially available solid compound which is stable at room temperature and can be easily handled. Scope of substrate and detailed reaction mechanism will be reported in this presentation.

References

[1] H. Shimakoshi, Y. Hisaeda, Chem. Rec., 2021, 21, 2080.

[2] Z. Luo, H. Shimakoshi et al, J. Org. Chem., 2021, 86, 5983.

[3] K. Shichijo, M. Fujitsuka, Y. Hisaeda, H. Shimakoshi, J. Organomet. Chem., 2020, 907, 121058.