The present invention relates to compounds which are suitable for use in electronic devices, and to electronic devices, in particular organic electroluminescent devices, comprising these compounds. The compounds have a dibenzofuran, dibenzothiophene or a fluorene group substituted in the 1-position, either directly or through a linking group, to a carbon atom of a heteroaromatic group with one or two nitrogen atoms in a bicyclic 6/6 core, or to a carbon or nitrogen atom of a heteroaromatic group with two nitrogen atoms in a bicyclic 5/6 core and is further substituted with a group selected from dibenzofuran, dibenzothiophene, fluorene or carbazole.