A major contributor to global warming and a cause of acid rain, carbon dioxide, is on the other hand a promising C₁ building block for fuels and chemicals through reductive transformations.

During their study using transition metals to reduce CO₂ with BH₃, Tsutomu Mizuta and colleagues, Hiroshima University, Higashi-Hiroshima, Japan, discovered a more straightforward route to serve that purpose. When they treat commercially available BH₃•THF solution stabilized with 0.5 mol% NaBH₄ with 1 atm CO₂ at room temperature, they obtain trimethoxyboroxine in 87 % yield. The reaction is presumably catalyzed by the BH₄^– anion.

As a new preparation method for trimethoxyboroxine, a common electrolyte additive, this process only requires inexpensive commercial reagents, and does not necessitate any catalyst, making it both convenient and atomically economic.

• Reduction of CO₂ to Trimethoxyboroxine with BH₃ in THF,
  Koji Fujiwara, Shogo Yasuda, Tsutomu Mizuta,
  Organometallics 2014.
  DOI: 10.1021/om5008488