A Two-Catalyst Photochemistry Route to Homochiral Rings

+ See all authors and affiliations

Science  25 Apr 2014:
Vol. 344, Issue 6182, pp. 368-369
DOI: 10.1126/science.1252965

You are currently viewing the summary.

View Full Text


Many biologically active compounds used in medicine and agriculture are still produced as a racemic mixture, even though only one isomer is actually active. The presence of the inactive isomer can lead to unwanted side effects. The efficient synthesis of only one stereoisomer—homochiral molecules—is a key goal in organic synthesis (1). Synthesizing homochiral molecules with light and a photocatalyst has been an unmet challenge for many years (2), yet the combination of light and catalysis to create chiral products is a hallmark of photosynthesis. On page 392 of this issue, Du et al. (3) report an efficient chiral selection by combining a transition-metal photocatalyst with a stereocontrolling cocatalyst. They obtained four-membered rings in good yields and with excellent enantioselectivity. This approach avoids the problems associated with the noncatalyzed background reaction, which hampers most photocatalytic processes.