title: Carbonylation reactions of intramolecular vicinal frustrated phosphane/borane Lewis pairs.
abstract: The intramolecular frustrated Lewis pair (FLP) Mes2PCH2CH2B(C6F5)2 4 adds cooperatively to carbon monoxide to form the five-membered heterocyclic carbonyl compound 5. The intramolecular FLP 7 contains an exo-3-B(C6F5)2 Lewis acid and an endo-2-PMes2 Lewis base functionality coordinated at the norbornane framework. This noninteracting FLP adds carbon monoxide in solution at -35 °C cooperatively to yield a five-membered heterocyclic FLP-carbonyl compound 8. In contrast, FLP 7 is carbonylated in a CO-doped argon matrix at 25 K to selectively form a borane carbonyl 9 without involvement of the adjacent phosphanyl moiety. The free FLP 7 was generated in the gas phase from its FLPH2 product 10. A DFT study has shown that the phosphonium hydrido borate zwitterion 10 is formed exergonically in solution but tends to lose H2 when brought into the gas phase.
authors.affiliation: Organisch-Chemisches Institut, Westfälische Wilhelms-Universität , Corrensstraße 40, 48149 Münster, Germany.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Sajid
authors.forename: Arunlibertsen
authors.initials: A
authors.lastname: Lawzer
authors.forename: Weishi
authors.initials: W
authors.lastname: Dong
authors.forename: Christoph
authors.initials: C
authors.lastname: Rosorius
authors.forename: Wolfram
authors.initials: W
authors.lastname: Sander
authors.forename: Birgitta
authors.initials: B
authors.lastname: Schirmer
authors.forename: Stefan
authors.initials: S
authors.lastname: Grimme
authors.forename: Constantin G
authors.initials: CG
authors.lastname: Daniliuc
authors.forename: Gerald
authors.initials: G
authors.lastname: Kehr
authors.forename: Gerhard
authors.initials: G
authors.lastname: Erker