Chromium catalyzed acceptorless dehydrogenative (cross)coupling of primary amines to secondary imines

We present here acceptorless dehydrogenative coupling of primary amines to form secondary aldimines catalyzed by a complex of Earth-abundant chromium. The reaction is promoted by Cr(DAFO)(CO)4 (DAFO = 4,5-diazafluorene-9-one) without using any additives, base or oxidant generating NH3 and H2 as sole by-products. Dehydrogenative cross-coupling of primary amines with aniline derivatives to unsymmetrical secondary imines was also achieved with good to excellent yields. A probable mechanism is proposed based on the stoichiometric investigation and computational studies.

Reframing primary alkyl amines as aliphatic building blocks

While primary aliphatic amines are ubiquitous in natural products, they are traditionally considered inert to substitution chemistry. This review highlights historical and recent advances in the field of aliphatic deamination chemistry which demonstrate these moieties can be harnessed as valuable C(sp3) synthons. Cross-coupling and photocatalyzed transformations proceeding through polar and radical mechanisms are compared with oxidative deamination and other transition metal catalyzed reactions.

In situ transformation of a tridentate to a tetradentate unsymmetric Schiff base ligand via deaminative coupling in Ni(ii) complexes: crystal structures, magnetic properties and catecholase activity study

An N₂O donor reduced Schiff base in presence of Ni(ClO₄)₂·6H₂O and SCN⁻ transforms into N₂O₂ donor ligand via deaminative coupling. Metal complexes 1 and 3 exhibit catecholase like activity and antiferromagnetic coupling between the Ni(ii) ions.