Reaction of Et 3 SiH + KO t Bu with diaryl ethers, sulfides and amines that feature an ortho alkyl group leads to rearrangement products. The rearrangements arise from formation of benzyl radicals, likely formed through hydrogen atom abstraction by triethylsilyl radicals. The rearrangements involve cyclisation of the benzyl radical onto the partner arene, which, from computation, is the rate determining step. In the case of diaryl ethers, Truce-Smiles rearrangements arise from radical cyclisations to form 5-membered rings, but for diarylamines, cyclisations to form dihydroacridines are observed.
The regioselective lithiation of 1,2,3-triazoles provides an opportunity to introduce additional functionality, however this simple functionalisation strategy using triazoles bearing electron-withdrawing N-substituents has not been investigated until now. Herein, we demonstrate that the lithiated triazole intermediates can readily decompose, even at −78 °C. In addition, lithiation-deuteration studies reveal lithiation can take place competitively on both the triazole and the electron-withdrawn aryl ring. Careful control of reaction conditions is therefore required to i) minimise decomposition pathways; and ii) facilitate regioselective functionalisation of the triazole.
The regioselective lithiation of 1,2,3-triazoles provides an opportunity to introduce additional functionality, however this simple functionalisation strategy using triazoles bearing electron-withdrawing N-substituents has not been investigated until now. Herein, we demonstrate that the lithiated triazole intermediates can readily decompose, even at À 78 °C. In addition, lithiation-deuteration studies reveal lithiation can take place competitively on both the triazole and the electronwithdrawn aryl ring. Careful control of reaction conditions is therefore required to i) minimise decomposition pathways; and ii) facilitate regioselective functionalisation of the triazole.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.