Non-thermal reaction triggered by a stimulated Raman process using 5-fs laser pulses in the electronic ground state: Claisen rearrangement of allyl phenyl ether

The vibrational populations of allyl phenyl ether were excited by a broadband visible 5-fs laser pulse by the stimulated Raman process to promote a ‘non-thermal’ Claisen rearrangement reaction in the electronic ground state. Analyses of the time-resolved vibrational spectra observed in the subpicosecond region has shown that the Claisen rearrangement proceeds in the following three-step pathway: (1) weakening of the C3O bond to generate a bis-allyl intermediate, (2) formation of the weak C1C5 bond results in the generation of a six-membered structure, and (3) simultaneous processes of C3O breaking and C1C5 formation leading to the generation of a keto-intermediate.