Sodium triacetoxyborohydride (NaBH(OAc)3, STAB-H) serves as a popular reducing reagent for direct reductive amination (DRA), alongside sodium cyanoboronhydride (NaBH3(CN)). In comparison to NaBH3(CN), STAB-H offers several advantages. Firstly, STAB-H is a safer reagent because it does not release toxic cyanide ions. Secondly, STAB-H exhibits high reactivity in various aprotic solvents, including DCE, THF, and dioxane. Thirdly, it can facilitate the reaction between weakly basic amines and nonbasic amines with the corresponding aldehydes/ketones. Consequently, it has gained widespread acceptance as a general reagent for reductive amination. The chart summarizes the reaction profiles and commonly used conditions for different types of substrates.
Reference:
Abdel-Magid, A. F.; Carson, K. G.; Harris, B. D.; Maryanoff, C. A.; Shah, R. D., Reductive Amination of Aldehydes and Ketones with Sodium Triacetoxyborohydride. Studies on Direct and Indirect Reductive Amination Procedures1. J. Org. Chem. 1996, 61, 3849-3862.