The generation of free radical VI from RAE 2 is depicted (Figure ) as involving Ni(I) species IV in analogy to studies from Baran in the coupling of anhydrides with redox-active esters. 11a The efficiency of product formation in the absence of zinc (Table ) illustrates that the nickel catalyst is competent in mediating the decomposition of redox-active esters. We observed that zinc and Et3SiCl rapidly promotes the decomposition of RAE 2, however, the presence of the nickel catalyst has a protective effect as previously described by Baran, slowing the rate of consumption of 2 compared to control experiments where the nickel catalyst is omitted (see SI). Recent studies from Rousseaux have provided evidence in reductive arylation reactions that TMSCl and Zn promote the formation of free radicals. Our studies, which potentially involve effects of the silyl chloride in several steps including aldehyde activation and/or redox-active ester decomposition, have not clearly elucidated the active agent in mediating radical formation from the redox-active ester. Finally, the role of 1,5-hexadiene is not illustrated in the mechanistic scheme since the 4-and 5coordinate complexes II and III cannot accommodate the bidentate coordination of this additive. Coordination of this additive likely prevents catalyst decomposition and/or inhibits competing side reactions that lie off the productive catalytic pathway. active esters has been developed. The procedure is broad in scope, tolerant of a wide array of functional groups, high-yielding, experimentally simply, and scalable. This process was extended to include the reductive cross-coupling of alkyl tosylates or epoxides with aliphatic aldehydes, thus providing a broad range of precursors derived from carboxylic acids, alcohols, or alkenes. Preliminary mechanistic experiments on this aldehyde -redox-active ester coupling are consistent with initial aldehyde activation to produce a-silyloxyalkylnickel species as a key intermediate that is captured by free radicals generated from the redox-active ester. Future work will include efforts to further study the mechanism of these transformation and expand the scope in increasingly complex applications.