The high nitrogen content and diverse reactivity of malononitrile are widely harnessed to access nitrogen-rich fine chemicals. Although the facile substitutions of malononitrile can give structurally diverse quaternary carbons, their access to enantioenriched molecules, particularly chiral amines that are prevalent in bioactive compounds, remains rare. Here we report a cobalt-catalysed desymmetric reduction of disubstituted malononitriles to give highly functionalized β-quaternary amines. The pair of cobalt salt and sodium borohydride is proposed to generate a cobalt-hydride intermediate and initiate the reduction. Meanwhile, the enantiocontrol of the dinitrile is achieved through a tailored bisoxazoline ligand with two large flanks that create a narrow gap to host the bystanding nitrile and thus restrict the C(ipso)−C(α) bond rotation of the complexed one. Combined with the extensive derivatization possibilities of all substituents on the quaternary carbon, this asymmetric reduction unlocks pathways from malononitrile as a bulk chemical feedstock to intricate, chiral nitrogen-containing molecules.

丙二腈的高氮含量和多种反应性被广泛用于获得富含氮的精细化学品。尽管丙二腈的简单取代可以产生结构多样的季碳，但它们获得对映体富集分子的机会，特别是生物活性化合物中普遍存在的手性胺，仍然很少见。在这里，我们报道了二取代丙二腈的钴催化不对称还原，得到高度官能化的 β-季铵胺。提出钴盐和硼氢化钠对生成钴氢化物中间体并引发还原。同时，二腈的对映体控制是通过定制的双恶唑啉配体实现的，该配体具有两个大侧面，形成一个狭窄的间隙来承载旁通的腈，从而限制络合物的 C（ipso）−C（α） 键旋转。结合季碳上所有取代基的广泛衍生化可能性，这种不对称还原解锁了从丙二腈作为本体化学原料到复杂的含手性氮分子的途径。