Catalytic Chan-Lam coupling using a 'tube-in-tube' reactor to deliver molecular oxygen as an oxidant.

A flow system to perform Chan-Lam coupling reactions of various amines and arylboronic acids has been realised employing molecular oxygen as an oxidant for the re-oxidation of the copper catalyst enabling a catalytic process. A tube-in-tube gas reactor has been used to simplify the delivery of the oxygen accelerating the optimisation phase and allowing easy access to elevated pressures. A small exemplification library of heteroaromatic products has been prepared and the process has been shown to be robust over extended reaction times.

Preparation of dicationic palladium catalysts for asymmetric catalytic reactions.

The synthesis of Pd(OTf)(2)·2H(2)O is described. This was used to generate two different types of chiral dicationic palladium complexes for highly enantioselective addition of aromatic amines to α, β-unsaturated conjugate alkenes ([(R-BINAP)Pd(OH(2))(2)][OTf](2) and [(R-BINAP)Pd(μ-OH)](2)[OTf](2)). The resulting optically active N-arylated β-amino acid derivatives are valuable synthetic intermediates for the synthesis of biologically active molecules and peptidomimetics.

Delineating origins of stereocontrol in asymmetric Pd-catalyzed alpha-hydroxylation of 1,3-ketoesters.

Systematic studies of reaction conditions and subsequent optimization led to the identification of important parameters for stereoselectivity in the asymmetric alpha-hydroxylation reaction of 1,3-ketoesters. Enantioselectivities of up to 98% can be achieved for cyclic substrates and 88% for acyclic ketoesters. Subsequently, the combination of cyclic/acyclic ketoester, catalyst, and oxidant was found to have a profound effect on reaction rates and turnover-limiting steps.

Palladium-catalysed enantioselective alpha-hydroxylation of beta-ketoesters.

Highly enantioselective alpha-hydroxylation of cyclic and acyclic 1,3-ketoesters can be achieved with up to 98% ee using a dicationic palladium(ii) catalyst and dimethyldioxirane as oxidant.