Visible-Light-Mediated Synthesis of Pyrazines from Vinyl Azides Utilizing a Photocascade ProcessThis work was supported by the German Science Foundation (DFG) (GRK 1626, Chemical Photocatalysis)
Received: 30 June 2017
Accepted after revision: 09 August 2017
16 August 2017 (eFirst)
Dedicated to Professor Albert Padwa on the occasion of his 80th birthday
Published as part of the ISHC Conference Special Section
A convenient method for the synthesis of substituted pyrazines from vinyl azides has been developed. This method is enabled by a dual-energy and electron-transfer strategy by visible-light photocatalysis. Initially, vinyl azides are activated by a triplet sensitization process from an excited ruthenium photocatalyst in the presence of water to form dihydropyrazines, followed by a single-electron-transfer (SET) process under oxygen (air) atmosphere that leads to the tetrasubstituted pyrazines in good to excellent yields.