Solar-Driven Incorporation of Carbon Dioxide into α-Amino Ketones

Naoki Ishida, Yasuhiro Shimamoto, and Masahiro Murakami
Angew. Chem. Int. Ed.
DOI: 10.1002/anie.201206166

Preparation of cyclic carbonates by incorporation of CO₂ into strained cyclic systems is well known and widely exploited. A standard synthesis of these compounds is through addition of epoxide into CO₂ followed by ring expansion. Murakami and co-workers take a similar approach in cyclic carbonate synthesis in order to demonstrate a process involving 2 goals in green chemistry: CO₂ incorporation, and sunlight activation.

The authors show that azetidine derivatives can be prepared from α-methylaminoketones through irradiation with sunlight alone. These high energy intermediates are relatively stable and their stored solar energy can be released in reaction with CO₂ under mild conditions. The reaction can tolerate various aryl groups, but chain length is fixed as a hydroxypyrrolidine derivative is too stable to undergo ring opening.