"But what if a CH bond is in the middle of a desert, so to speakfar from the nearest functional group?" said Yu. "And what if it is also on the hard-to-access meta position, facing away from the nearest functional group in terms of geometry? How do you reach out so far and then around, to cut it?"
In the new study, Yu and his team showed just how to do this with a chemical structure that can deliver bond-breaking palladium to a relatively remote CH site, more than a dozen bonds distant from the nearest functional group. The lengthy, modifiable structure includes a nitrile (a carbon-nitrogen group) and has a flexibility that allows it to act like a crane swinging a wrecking ball. "It brings the palladium out and around to the CH bond at the meta position, and it has the right length and angle so that it will not touch any other positions," said Li.
"It overwhelms the intrinsic preference for other usually more reactive and accessible CH bonds," said Leow.
'Just a Small Sample of the Possibilities'
The team used the technique to quickly modify a variety of compounds, including the amino acid phenylalanine and the neurotransmitter-mimicking drug baclofen. "These are from compound classes that chemists use routinely to synthesize new candidate drugs and other useful
|Contact: Mika Ono|
Scripps Research Institute