Chemists have created a variant of the ubiquitous and synthetically important molecule indole, substituting a boron-nitrogen unit for the pair of carbons that bridge the compound’s two fused rings (J. Am. Chem. Soc., DOI: 10.1021/ja107312u). Eric R. Abbey, Lev N. Zakharov, and Shih-Yuan Liu of the University of Oregon say the molecule is the first of a new class of compounds dubbed BN-fused indoles, which can be expected to broaden the chemistry of indole-type species that are crucial to drug discovery. “These BN-substituted biomolecules may provide scientists with a unique marker for tracing biological pathways, or impart unique chemical and spectroscopic properties to classic structural motifs used in chemical biology and drug discovery,” Liu tells C&EN. The researchers synthesized the tert-butyl BN indole shown and confirmed its structure via X-ray crystallography. They found that the BN indole is even more nucleophilic than its natural indole analog in undergoing regioselective electrophilic aromatic substitution.