Titanium‐Catalyzed Intermolecular Hydroaminoalkylation of Alkenes with Tertiary Amines

The first cationic titanium catalyst system for the intermolecular hydroaminoalkylation of alkenes with various tertiary alkylamines is presented. Corresponding reactions which involve the addition of the α‐C−H bond of a tertiary amine across the C−C double bond of an alkene take place at temperatures close to room temperature with excellent regioselectivity to deliver the branched products exclusively. Interestingly, for selected amines, α‐C−H bond activation occurs not only at N‐methyl but also at N‐methylene groups. Tertiary amines can be used as substrates for the highly regioselective intermolecular hydroaminoalkylation of alkenes in the presence of a cationic titanium catalyst generated in situ from tetrabenzyltitanium and Ph3C[B(C6F5)4]. While in most cases, the involved C−H bond activation reaction occurs at N‐methyl groups, N‐methylazepane and N‐methylpyrrolidine also undergo alkylation at the methylene group in position α to the nitrogen atom.