Cyano-borrowing: titanium-catalyzed direct amination of cyanohydrins with amines and enantioselective examples

The direct amination was developed of cyanohydrins with amines via catalytic cyano-borrowing reaction based on the use of a titanium catalyst supported by quinine and (S)-BINOL ligands.

Titanium-based phenoxy-imine catalyst for selective ethylene trimerization: effect of temperature on the activity, selectivity and properties of polymeric side products

A thermal switch of selectivity for a phenoxy-imine titanium catalyst was studied by combining kinetic studies and a “polymer-to-catalyst” approach.

Hydroaminoalkylation of Allenes

The first examples of early-transition-metal-catalyzed hydroaminoalkylation reactions of allenes are reported. Initial studies performed with secondary aminoallenes led to the identification of a suitable titanium catalyst and revealed that under the reaction conditions, the initially formed hydroaminoalkylation products undergo an unexpected titanium-catalyzed rearrangement to form the thermodynamically more stable allylamines. The assumption that this rearrangement involves a reactive allylic cation intermediate provides a simple explanation of the fact that no successful early-transition-metal-catalyzed hydroaminoalkylations of allenes have previously been reported. As a result of the generation of the corresponding cation, the titanium-catalyzed intermolecular hydroaminoalkylation of propa-1,2-diene unexpectedly gives an aminocyclopentane product formed by incorporation of two equivalents of propa-1,2-diene.