Generation and Trapping Reactions of a Formal 1:1 Complex between Singlet Carbon and 2,2′-Bipyridine

The structural element of a protonated imidazolium system was realized for the first time in the synthesis of 1 from 2,2'-bipyridine and a novel methylenating agent. Reversible deprotonations proceed via 2 to lead to carbene 3, a formal 1:1 complex between singlet carbon and 2,2'-bipyridine which is stable in solution and can be trapped. For 1 and 2, unusual hybridizations of the bridging C atom were found experimentally.