Correction to: Nature Chemistry https://doi.org/10.1038/s41557-020-0489-1, published online 29 June 2020.

In the version of this Article originally published, in Table 1, the methyl group in compound 3af appeared in the wrong position. This incorrectly showed compound 3af to have the same structure as compound 3ag. This has been corrected in the online versions of this Article.