Metal-free photochemical silylations and transfer hydrogenations of benzenoid hydrocarbons and graphene.

ABSTRACT: The first hydrogenation step of benzene, which is endergonic in the electronic ground state (S₀), becomes exergonic in the first triplet state (T₁). This is in line with Baird's rule, which tells that benzene is antiaromatic and destabilized in its T₁ state and also in its first singlet excited state (S₁), opposite to S₀, where it is aromatic and remarkably unreactive. Here we utilized this feature to show that benzene and several polycyclic aromatic hydrocarbons (PAHs) to various extents undergo metal-free photochemical (hydro)silylations and transfer-hydrogenations at mild conditions, with the highest yield for naphthalene (photosilylation: 21%). Quantum chemical computations reveal that T₁-state benzene is excellent at H-

SUBMITTER: Papadakis R 

PROVIDER: S-EPMC5059713 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature