were also suitable coupling partners in the process. When the substrate contains both an aldehyde and ketone functional group (3k), the reaction is completely selective for aldehydes, leaving the ketone unchanged. We next demonstrated the generality of this protocol with respect to the trifluoromethyl alkenes 2a-t (Table ). Under these mild and base-free conditions, various 1,1trifluoromethylstyrenes featuring either electron-rich (4a-4e) or electron-deficient (4g-4k) substituents underwent the transformation smoothly, affording the corresponding products in good yields (71-93%). Notably, this reductive protocol is tolerant of a wide range of functionality on the alkene coupling partner, such as esters (4i), amides (4j), sulfonyl groups (4k), nitriles (4l), and sulfides (4m). Furthermore, heterocycles including quinolone (4o), benzofuran (4p), benzothiophene (4q), dibenzofuran (4r), and carbazole (4s), are also readily compatible. It is noteworthy that beyond the aryl and heteroaryl system, mono-substituted alkenes, such as To showcase the robustness and practicality of our method, a 5-mmol-scale experiment was conducted under an inert atmosphere using a benchtop setup without glovebox manipulations to provide 1.5 g of the desired product 3a in 73% yield using only 2 mol% catalyst loading (Scheme 2A). Additionally, the protocol was also expanded to include a-trifluoromethyl enoates. As shown in Scheme 2B, subjecting methyl 4,4,4-trifluorocrotonate (5) to this catalytic system exclusively provided the defluorinative alkylation product 6 in high yield, illustrating that the trifluoromethyl group directs regiochemistry of the addition in analogy to the examples provided in Tables and. Alkyl-substituted trifluoromethyl alkene (7), however, did not participate in the process, and A related chromium-catalyzed method for the addition of ketyl radicals to trifluoromethyl alkene intermediates was recently described by Wang. Notably, the use of nickel catalysis was described in that study as ineffective in promoting the reaction, illustrating the unique effectiveness of the ligand/additive/reductant combination developed herein. ICP analysis illustrated that trace levels of chromium (0.4 ppm) are present in the commercial samples of NiCl 2 (DME) that were used in this study. Control experiments, however, illustrated that CrCl 3 , used in the method of Wang, has little effect on rates or outcomes of our optimal nickel-catalyzed conditions, suggesting that co-catalysis with trace chromium is not involved in the method describe herein (see supporting information for details). Notably, our recent report of aldehyde couplings with redox-active esters illustrated that stoichiometric Ni(COD) 2 in the absence of Zn or Mn reductants led to high yields of product, suggesting that the catalytic process involves catalyst turnover by the terminal reductant and that reduction of intermediates that precede product formation are not strictly required. In couplings of trifluoromethyl alkenes, however, the use of stoichiometric Ni(COD) 2 in the absence of a terminal reductant led only to trace product formation (7 % isolated yield). This outcome suggests that the reduction of Ni(II) species I to Ni(I) intermediate II is likely required in the current protocol.