With optimal reaction conditions for the CAA process to form a-branched secondary amines in hand, we explored the scope of the transformation with respect to the primary amine component in combination with representative linear and abranched aldehydes (2a-b) and isopropyl iodide (3a) (Figure ). We report assay yields alongside isolated yields for all reaction products in order to accurately represent the reaction efficiency. A range of functionalized primary alkylamines were found to be compatible with the CAA process and produced generally good yields of a-branched secondary alkylamines (4) after isolation. Beyond the optimization substrate derived from benzylamine (4b), a series of linear primary alkylamines (4c-e), a-amino acids (4f), and amines containing electrondeficient (4g-h) and electron-rich heteroaryl (4i) groups all worked well in the CAA reaction. Throughout the course of our studies, we found that substrates featuring basic heterocycles typically benefitted from employing HFIP in cosolvent quantities (4:1 CH2Cl2/HFIP): imidazole-containing product 4h was formed in quantitative yield under these conditions. The use of TMSCl was also of particular importance in this case; omission of TMSCl, or use of the standard equivalency of HFIP, resulted in low yields. Further observations of this CAA process include the accommodation of unprotected, potentially-competitive two-electron nucleophiles (4c -furan; 4i -indole) in the primary alkylamine component. a-Branched primary amines were also good substrates and delivered the corresponding products that displayed a-branching on both substituents on the nitrogen atom of the secondary alkylamine (4j-l). An aromatic primary amine was also a competent substrate (4m). Importantly, a-tertiary primary alkylamines are competent substrates in this CAA reaction, the use of which forges extremely hindered secondary alkylamines in good yields (4no). The synthesis of this type of product via classical carbonyl reductive amination would require forcing conditions for the imine formation step because of the steric hinderance in both a-tertiary primary amine and a-branched dialkyl ketone components, which may preclude the incorporation of more delicate functionality. Finally, we found that Hantzsch dihydropyridine and steroid-derived alkylamine-containing pharmaceuticals were effective substrates for the CAA reaction, delivering the corresponding products in good yield (4p-q). It is particularly notable that the CAA reaction tolerates the presence of unprotected protic functionality (4d, 4i, 4j, 4p) which would be incompatible with organometallic approaches to these structures.