Journal article

Regioselectivity of aryl radical attack onto isocyanates and isothiocyanates

Geethika K Weragoda, Rowan L Pilkington, Anastasios Polyzos, Richard AJ O'Hair



The combination of multistage mass spectrometry experiments employing the distonic radical approach together with DFT calculations are used to examine addition of the N-methyl-pyridinium-4-yl radical cation (γ-NMP) to iso(thio)cyanates in the gas-phase. The type of products formed depend on the nature of the iso(thio)cyanate: (1) hydrogen atom abstraction occurs for alkyl isocyanates; (2) aryl isocyanates undergo radical-ipso substitution; (3) radical attack occurs at the C[double bond, length as m-dash]C bond of allyl isocyanate; (4) radical attack occurs at the C[double bond, length as m-dash]S bond of isothiocyanates to generate S adducts of γ-NMP and isonitriles. DFT calculations provide..

View full abstract


Awarded by CSIRO

Funding Acknowledgements

GKW gratefully acknowledge CSIRO ResearchPlus PostDoctoral Fellowships program. RAJO and AP thank the Australian Research Council and the CSIRO for financial support (DP180101187 and CSIRO ResearchPlus Office). The DFT calculations were carried out using the HPC facility of The University of Melbourne (punim0255), the National Computing Infrastructure (da67) and the Ohio Supercomputer Center (we thank Prof. Anna D. Gudmundsdottir for access). We also thank Professors Allan Canty and Uta Wille and Dr Lars Goerigk for discussions regarding the DFT calculations.