12 Cyclisations of substrates based on hydroamination of Boc-tetrahydropyridine 5c with glycine ester 6a were also successful, in line with our previous construction of diazabicyclo [3.3.1]nonanes: the simple Cbz and POC-protected scaffolds 6f/g were returned in higher yield than the corresponding [4.2.1] products 6c-e, which may be indicative of the relative degrees of strain in the products (vide infra). The incorporation of backbone substituents on the coupling partners 5 and 8 was also probed: use of an αsubstituted amino ester (ethyl phenylalaninate 8c) led to a mixture of diastereomers in the hydroamination step, only one of which cyclised to give a modest yield of the desired bicyclic product 6h (relative configuration determined by NOE studies, Supporting Information). Pleasingly, hydroamination using Boc 3-methyltetrahydropyridine 5d led ultimately to bridgeheadsubstituted bicycle 6i in a notably higher yield than for 6f, perhaps reflecting a lower energy penalty to access the reactive conformation for lactamisation: again, this substitution pattern would not be available through routes based upon reductive amination chemistry. Larger ring systems containing diazabicyclo[4.3.1]decanes could be accessed either through hydroamination of Boc tetrahydropyridine 5c with ethyl aminopropionate 8b, or as an isomeric lactam through the coupling of the dehydroazepine 5e with ethyl glycinate 8a. Regardless of the location of the amide (in the six-or seven-membered ring in 6j and 6k respectively), the cyclisations occurred in good yield, as was also seen in the cyclisation to give the homologous diazabicyclo[4.4.1]undecane 6l.