🇪🇺 EMA Q&A Rev. 16 EMA/409815/2020 - MAJOR UPDATE

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Please do not miss the post from @ccdw regarding activating feature ‘Methyl group bonded to beta-carbon’

CPCA - Methyl group bonded to beta carbon (cyclic/acyclic) (activating factor)

One of the NITWG identified activating features in the CPCA approach (Table 4 of Annex 2 of EMA Q&A Rev. 16) is the beta-methyl activating feature (methyl group bound to beta carbon, cyclic or acyclic): [pic1] The NS OEG has clarified: The beta-methyl has to do with theoretic motivations of carbocation stabilization, just a chemical-mechanistic reason (theoretical). A more stable carbocation is more likely to form. (cf. 1,2-methyl shifts and 1,2-hydride shifts) What do you think about such …