Electrophilic amination of Cu(I) catalyzed phenylmagnesium bromide with N,O-bis(Trimethylsilyl)hydroxylamine in THF:N-donor solvent. Control of C–N and C–O chemoselectivity

Publication date: Available online 31 July 2019Source: Journal of Organometallic ChemistryAuthor(s): Didem Kahya, Fatma EroğluAbstractReaction of PhMgBr with (Me3Si)HNO(SiMe3)[TMSHA] in the presence of CuI or CuCN catalysis (10–20 mol %) in THF:cosolvent (cosolvent = HMPA or TMEDA) at room temperature can provide an atom-economic and step-economic access for arylamine synthesis starting from aryl Grignard reagents. Chemoselectivity to yield C–N or C–O coupling can be controlled by changing reaction parameters. Cu(I) catalyzed reaction of PhMgBr in THF or in THF:HMPA (or TMEDA) affords both C–N and C–O coupling products, i.e. aniline and phenol (mol ratio ≥ 7:3), whereas uncatalyzed reaction of PhMgBr gives phenol. Mechanisms were proposed for the solvent dependence of chemoselectivity in the coupling of both uncatalyzed and Cu(I) catalyzed Grignard reagent with (TMS)HNO(TMS).Graphical abstract

Source: Journal of Organometallic Chemistry - August 1, 2019 Category: Chemistry Source Type: research