The activation of molecules possessing homonuclear bonds (i.e., X–X, where X = Br, O, S, or C) using a stable N,N′-diamidocarbene (DAC) is described. Exposing bromine to the DAC at 25 °C afforded a substituted tetrahydropyrimidinium salt in good yield (70%). In contrast, treatment of the DAC with benzoyl peroxide or various disulfides afforded the corresponding diamidoketal or diamidothioketal products, respectively, under mild conditions (25 °C) and in good yield (60–80%). Mechanistic and kinetic studies of the latter reactions were consistent with a concerted process involving the nucleophilic attack of the DAC on the aforementioned substrates. While the diamidoketal decomposed to the corresponding urea (91% yield) at 25 °C, the diamidothioketals produced a thiolate which induced rearrangement to the corresponding ring-opened thioesters (78–90% yield) at elevated temperatures (60 °C). The DAC also inserted into the C(O)–C(O) bond of cyclic and acyclic diones as well as the C(O)–CR bond of a cyclopropenone under mild conditions (25–60 °C); the corresponding products were subsequently isolated in good yield (75–90%).
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