Direct amidation of metallaaromatics: access to -functionalized osmapentalynes a 1,5-bromoamidated intermediate.

The direct C-H amidation or imidation of metallaaromatics with -bromoamides or imides has been achieved under mild conditions and leads to the formation of a family of -functionalized metallapentalyne derivatives. A unique 1,5-bromoamidated species has been identified, and can be viewed as a σ-adduct intermediate in a nucleophilic aromatic substitution. The 1,5-addition of both electrophilic and nucleophilic moieties into the metallaaromatic framework demonstrates a novel pathway in contrast to the typical radical process of arene C-H amidation involving -haloamide reagents.