Novel densely functionalized β2,2-amino acids were obtained in almost enantiopure form using down to 20 ppm of a chiral phase-transfer catalyst.

A nickel-catalyzed asymmetric reductive hydroarylation of vinyl amides to produce enantioenriched a-arylbenzamides is reported. The use of a chiral bisimidazoline (BIm) ligand, in combination with diethoxymethylsilane and aryl halides, enables the regioselective introduction of aryl groups to the internal position of the olefin, forging a new stereogenic center a to the N atom. The use of neutral reagents and mild reaction conditions provides simple access to pharmacologically relevant motifs present in anticancer, SARS-CoV PLpro inhibitors, and KCNQ channel openers.

Graphical abstract

A detailed study of literature-known and novel S-containing pincer-type ligands for ruthenium-catalyzed homogeneous hydrogenation and dehydrogenation reactions was carried out. The scope and limitations of these catalysts were carefully investigated, and it was shown that simple bench-stable SNS−Ru complexes can be used to facilitate the hydrogenation of a variety of different substrates at a maximum H 2 pressure of 20 bar under operationally simple, easy to scale up, gloveboxfree conditions by using starting materials and reagents that do not require any special purification prior to use. It was also shown that such complexes can be used to catalyze the dehydrogenative coupling of alcohols and amines to get amides as well as for the dehydrogenative dimerization of alcohols to esters.

The use of electrophilic cyanide-transfer reagents has become a versatile strategy to access important structural motives in a complementary way compared to other methods.