Fig. 6. Proposed mechanism of the Fom3-catalyzed reaction. (A) HEP-CMP radical (41) is quenched by the transfer of methyl radical from Me-Cbl(iii) to give Cbl(ii), which is reduced to Cbl(i) in order to accept a new methyl group from SAM. (B) Transfer of methyl cation to HEP-CMP ketyl radical (47) followed by reduction and protonation of product radical (48).
