Chemists in New Jersey have identified a new carbon–carbon bond-forming reaction by using an automated, high-throughput method to test more than 1,000 combinations of chemicals.

Many important discoveries in chemistry have been accidental, so David MacMillan and his colleagues at Princeton University decided to harness serendipity to look for new and unusual chemical reactions. They combined functional organic groups that they did not expect to react with one another and exposed them to light-activated catalysts.

The method paid off, revealing a reaction that activates a carbon atom bonded to nitrogen in an amine, and adds another carbon to it. The researchers used the reaction to generate, under mild conditions, a variety of benzylic amines, which are found in many pharmaceutical compounds.

Science 334, 1114–1117 (2011)