title: Controlling the regioselectivity of the hydrosilylation reaction in carbon nanoreactors.
abstract: Hollow graphitized carbon nanofibres (GNF) are employed as nanoscale reaction vessels for the hydrosilylation of alkynes. The effects of confinement in GNF on the regioselectivity of addition to triple carbon-carbon bonds are explored. A systematic comparison of the catalytic activities of Rh and RhPt nanoparticles embedded in a nanoreactor with free-standing and surface-adsorbed nanoparticles reveals key mechanisms governing the regioselectivity. Directions of reactions inside GNF are largely controlled by the non-covalent interactions between reactant molecules and the nanofibre channel. The specific π-π interactions increase the local concentration of the aromatic reactant and thus promote the formation of the E isomer of the β-addition product. In contrast, the presence of aromatic groups on both reactants (silane and alkyne) reverses the effect of confinement and favours the formation of the Z isomer due to enhanced interactions between aromatic groups in the cis-orientation with the internal graphitic step-edges of GNF. The importance of π-π interactions is confirmed by studying transformations of aliphatic reactants that show no measurable changes in regioselectivity upon confinement in carbon nanoreactors.
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
authors.forename: William A
authors.initials: WA
authors.lastname: Solomonsz
authors.forename: Graham A
authors.initials: GA
authors.lastname: Rance
authors.forename: Mikhail
authors.initials: M
authors.lastname: Suyetin
authors.forename: Alessandro
authors.initials: A
authors.lastname: La Torre
authors.forename: Elena
authors.initials: E
authors.lastname: Bichoutskaia
authors.forename: Andrei N
authors.initials: AN
authors.lastname: Khlobystov