Identification of a lead candidate in the search for carbene-stabilized homoaromatics

The effect of carbenes as Lewis donor groups on the homoaromaticity of mono- and bicyclic organic molecules is surveyed. The search for viable carbene-stabilized homoaromatics resulted in a large amount of rejected candidates as well as nine promising candidates that are further analyzed for their homoaromaticity using a number of metrics. Of these, five appeared to show modest homoaromaticity, while another compound showed a level of homoaromaticity comparable with the homotropylium cation benchmark compound. Isoelectronic analogues and constitutional isomers of the lead compound were investigated, however, none of these showed comparable homoaromaticity. The implications of these calculations on the design of donor-stabilized homoaromatics are discussed.