Despite the ready availability and ease of synthesis, primary phosphines remain underutilized as synthons in preparation of value-added organophosphines. Herein, we report the catalytic synthesis of phospholes with an iron catalyst CpFe(CO)2Me (Cp = ?5-C5H5). Reaction of primary aryl or alkyl phosphines with either diene or 2 equiv. of alkyne yields the corresponding phosphole in modest to high yields. This work provides a compliment to recent reports of catalytic phosphole syntheses with palladium by use of an earth-abundant catalyst and avoiding pre-fabricated P�C bonds in the substrate as well as previous work where electrophilic, metal-supported phosphinidenes allowed stoichiometric access to phospholes. The observed reactivity is most akin to a-elimination, or the extrusion of a low-valent fragment. Indeed, reaction of primary phosphine with catalytic CpFe(CO)2Me in the absence of unsaturated substrate afford dehydrocoupling products. Exploration of catalysis scope and mechanism will be presented.

Iron-catalyzed synthesis of phospholes from primary phosphines

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.