1a could be selectively deuterated by D2 in the presence of 5 mol % of [Ni(CO)(Cp*)]2 (Cp* = C5Me5) (Scheme 2). After 20 hours at 80 °C, the 1 H NMR spectrum showed the partial deuteration with formation of d-1a (82 % D-incorporation), as well as formation of H2 and HD. After three recharges with D2 near complete conversion was observed and d-1a was isolated in 90 % yield (>95 % Dincorporation). Under similar conditions, the analogue 1b instead underwent a selective dehydrocoupling to yield 3 and H2 (Scheme 3). The transformation could be performed catalytically with 10 mol% of [Ni(CO)Cp]2, giving 53 % in situ yield to complex 3. Improved in situ yields were obtained using [Ni(CO)(Cp*)]2 as a catalyst with 10, 5 and 2.5 mol% loadings leading to 82, 75 and 52 % yield of 3 after 20 h at 80 ºC. Using the highest catalyst loading 3 could be obtained as a crystalline colourless solid in 75% isolated yield. 2 is catalytically competent in the dehydrocoupling process but forms the product in lower yield (35 % vs 53%) than [Ni(CO)Cp]2 when applied at the same loading. The reaction could be effectively inhibited by addition of TEMPO but not 9,10-dihydroanthracene. Nickel(0) complexes including [Ni(COD)2] and [{Ni(PCy3)}2--N2] proved less effective for catalysis leading to formation of 3 in a maximum of 40% in situ yield at 10 mol% loading of Ni. The overall reaction to form 3 from 1b releasing dihydrogen is calculated to be exergonic with ΔG°298K = -14.6 kcal mol -1 and the reverse transformation, hydrogenation of 3, does not occur when [Ni(CO)(Cp*)]2 was employed as the catalyst.