Correction: Metal-free oxidative ring contraction of benzodiazepinones: an entry to quinoxalinones

Abstract

Correction for ‘Metal-free oxidative ring contraction of benzodiazepinones: an entry to quinoxalinones’ by Hasan Mtiraoui, et al., Org. Biomol. Chem., 2017, 15, 3060–3068.

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The authors regret that there were errors in some of the structures. The reactions to obtain compounds 2h and 2i were in fact carried out from 7-methoxy-benzodiazepinones 1h and 1i, and not from the regioisomer 8-methoxy-benzodiazepinones as reported. Consequently, the 6-methoxyquinoxalinones 2h and 2i were formed (and not the regioisomer 7-methoxyquinoxalinones). Subsequent compounds 5, 6 and 8 (Fig. 2, and Scheme 4) prepared from 2i should be modified accordingly.

The correct structures and corrected Fig. 2 and Scheme 4 are shown below.

Fig. 2 (a) Preparation of the hydroxyl-containing quinoxalinone 5. (b) Fluorescence emission spectrum of quinoxalinone 2i (λ_ex 366 nm, λ_em 475 nm) in PBS 7.4 at 25 °C, before (dashed line) and after (black line) the addition of NaBH₄.

Scheme 4 Application to the preparation of the fluorescently labelled cholesterol derivative 8.

In addition, compounds 2h, 2i, 5, 6 and 8 were named incorrectly in the Experimental section and should also be amended accordingly.

The original ESI has been updated with a corrected version showing the corrected structures and including 2D NMR data in support of the formation of 6-methoxyquinoxalinones 2h and 2i.

The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.

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Footnotes

† Electronic supplementary information (ESI) available: ¹H and ¹³C NMR, 2D NMR data in support of the formation of 6-methoxyquinoxalinones 2h and 2i, photophysical data for all new compounds, and X-ray crystallographic data (CIF files) for compound 2a. CCDC 1519664. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7ob00205j

‡ These authors contributed equally to this work.

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