One-Step Process for the Regiodivergent Double Hydrocyanation of 1,3-Butadiene

In industry, the two important nitrile starting materials, adiponitrile and 2-methylglutaronitrile, are primarily manufactured through the well-known DuPont process, which consists of a tandem sequence including first hydrocyanation, isomerization and second hydrocyanation. However, this mature process has the intrinsic defects of step efficiency and regioselectivity. Herein, we report a nickel-catalyzed divergent, one-step double hydrocyanation of 1,3-butadiene to produce either adiponitrile or 2-methylglutaronitrile in high regioselectivity. The key to this success lies in the highly tunable binding pockets of the bidentate phosphite ligands, which creates a geometrically defined coordination space around the nickel center. The first hydrocyanation that produces either the linear or branched alkenyl nitrile was identified as the selectivity-determining step. Organometallic studies confirm the formation of well-defined diphosphite nickel diene complexes in solution, and the role of ligands in dictating regioselectivity was further rationalized by DFT computations. This result provides the first example of a highly selective nickel-catalyzed synthesis of adiponitrile and 2-methylglutaronitrile from butadiene, and it also represents a high-level of catalyst-controlled regioselectivity via the fine-tuning of ligand pocket geometry.

Pd-catalysed synthesis of oxomalonamides through adjacent triple carbonylation of tertiary amines

The monocarbonylation and dicarbonylation reactions are well-established reactions in carbonylation chemistry. This work reports unusual oxidative adjacent triple carbonylation of the tertiary amine towards oxomalonamide synthesis using a Pd catalyst. The protocol involves the use of inert tertiary amines as an active reservoir of secondary amines through sp3 C-N bond activation using O2 as an ideal oxidant.

A Selective and General Cobalt-Catalyzed Hydroaminomethylation of Olefins to Amines

A new cobalt catalyst is presented for the domino hydroformylation-reductive amination reaction of olefins. The optimal Co-tert-BuPy-Xantphos catalyst shows good to excellent linear-to-branched (n/iso) regioselectivity for the reactions of aliphatic alkenes with aromatic amines under mild conditions. This system is far more selective than traditional cobalt(I) catalysts and even better than most known rhodium catalysts.