In terms of RAE scope, alkyl groups that are prone to isomerization (i.e., not bearing a stabilizing a-heteroatom), bridgehead, strained, and αheteroatom containing systems can all be employed. One striking finding relative to other aryl-alkyl couplings of any kind is the low levels of isomerization observed in the cross coupling of tertiary cyclic substrates relative to our previous reported conditions and to other reported methods (employing alkyl bromides). For the aryl scope, a broad range of aryl and heteroaryl partners are competent in this coupling to deliver synthetically useful quantities of product. While the yields in some cases may be modest (ca. 20% yield) there are currently no other viable options for such direct couplings. The reaction appears to be quite general across a range of coupling partners as documented with the synthesis of molecules . The mildly reductive nature of the reaction tolerates numerous functional groups, such as esters, ketones, amides, nitriles, ethers, Boc/Cbz protecting groups, aryl halides, aryl thioethers, cyclopropanes, oxetanes, and azetidines. Products bearing an ortho-substituent on the arene, such as 37 and 52, are also accessible. In terms of limitations, 2-halo pyridines and 2-halo pyrimidines are unreactive. This can be exploited in the case of