Apart from the synthesis of the ligand (Naph 2 carbH, 1) and the phosphine oxides, all products described were treated with rigorous exclusion of air and water using standard air-sensitive handling techniques which included bench-top operations (Schlenk line) and glove-box techniques. NMR samples of air and moisture sensitive compounds were prepared using glove box techniques and contained in Young's tap modified borosilicate glass NMR tubes. NMR **data** were collected on either a Bruker DPX300, DPX400, AV400, AV(III)400, AV(III) 400HD or AV(III)600 spectrometer. Chemical shifts are quoted in ppm relative to TMS ( 1 H, 13 C{ 1 H}) and H 3 PO 4 ( 31 P, 31 P{ 1 H}). Reaction progress was monitored by quantitative 31 P, 31 P{ 1 H} NMR spectroscopy (inverse gated decoupled) of samples prepared in dry, non-deuterated toluene, with a C 6 D 6 insert for locking. Apart from the substrates employed in Entries 8-9, Table 2, which were prepared following reported procedures; [77] all reagents were used as received. Magnetic moments were calculated through the Evans method at 298 K, employing C 6 D 6 as solvent. Diamagnetic corrections were calculated according to Pascal's constants. [78] CCDC 1874664-1874672 contain the supplementary **data** for 3-9, 4-CO and 20 a. These **data** can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif. Safety warnings: 1-Naphthylamine is highly toxic and is suspected to be a carcinogen; great care must be taken during synthesis and adequate handling of waste should be procured. Carbon monoxide is an extremely toxic and flammable gas, good ventilation within a fumehood should be procured when running a Schlenk line with this gas as source, away from open flames and with a carbon monoxide detector operating at all times.