Accessing enriched amines often demands security and deprotection procedures alterations, and purification processes that increase cost and waste, restricting applicability. When diastereomers can be shaped, one isomer is achievable. We show that nitriles viewed as reactive, can be transformed to multifunctional unprotected amines by addition of a nucleophile and diastereodivergent reduction of the consequent ketimine. Successful implementation requires that catalysts be present simultaneously and the slower-forming and reactive one engages first. This challenge was addressed by incorporation of a nonproductive side cycle, fueled by inexpensive additives, to delay the role of the catalyst that was more active. The usefulness of this approach is highlighted by its application to the efficient preparation of the anticancer agent (+)-tangutorine.