To complement the toxicological assessment for the Ni foam system, we identified the byproducts formed in the ECH of 1b (Scheme 8). We identified cyclohexanol 3b, 1,1-diethoxycyclohexane 4, and 3ethoxycyclohexanone 5 as byproducts in less than 0.5%, 0.5%, and 1.8%, respectively. Their concentrations were determined by GC-MS-FID using a calibration curve (see the Supporting Information, Section S8 and Scheme S5). None of these compounds represents a toxicological hotspot in comparison with other components in the reaction mixture. Recognizing the greater abundance of nickel compared to palladium, the Ni-foam system holds promise as a potential alternative to the conventional Pd system, and thus we proceeded to explore the scope and limitations when applied to a variety of mono-, di-, and trisubstituted alkenes (Scheme 7). Pt counter electrode and ethanol were used for the scope due to their robustness and availability, respectively. Unfunctionalized and electron-rich para-substituted benzylidene acetones gave the corresponding products 2c-2f in yields ranging from 55 to 77%. Alkene 1g, with a para-bromide substituent on the aryl group, gave reduced 2g in 42% yield. meta-Substituted benzylidene acetones showed an unusual reactivity. The meta-methyl-substituted derivative gave the desired product 2h in a good 61% yield, but a significant drop in performance was observed for the corresponding methoxy, hydroxy, and bromo derivatives. The products 2i-2k and were obtained in 23, 44, and 21% yields, respectively. The influence of steric hindrance was confirmed by the poor performance of ortho-substituted benzylidene acetones 1l and 1m (24 and 33% yields, respectively). Hindrance on the -carbon of the enone was relatively well tolerated, as shown in the hydrogenation of tert-butyl ketone 1n (63% yield). Interestingly, the hydrogenation of both the alkene and the nitro groups in 1o took place when the acidity was increased slightly, yielding 2o was obtained in 40% yield. The presence of a para-substituted pyridine and an ester group were tolerated, and the corresponding saturated derivative 2p was obtained in 62% yield. meta-Pyridinyl analog 1q reacted in a significantly lower yield of 20%.