Synthesis of Chiral α-Aryl Ketones by Photoredox/Nickel-Catalyzed Enantioconvergent Acyl Cross-Coupling with Organotrifluoroborate.

Photoredox/nickel-catalyzed enantioconvergent acyl cross-coupling of carboxylic derivatives with racemic secondary organotrifluoroborate was developed for the synthesis of an enolizable chiral α-aryl ketone under mild neutral conditions. Moderate to high yields and good enantioselectivities were achieved.

Nickel/Titanocene-Catalyzed Electrophilic Acylation Coupling of Styrene Oxides.

The cross-coupling of epoxides with acyl chlorides or anhydrides by a nickel/titanocene dual catalytic system is established. A variety of synthetically useful ß-hydroxy ketones were obtained in good to high yields by using modified pyridine-oxazoline ligand. The reaction proceeds via the cooperation of titanocene-catalyzed ring-opening of epoxides and nickel-catalyzed acylation of the benzylic radical intermediate.

Ni-Catalyzed enantioselective reductive arylcyanation/cyclization of N-(2-iodo-aryl) acrylamide.

A Ni/(S,S)-BDPP-catalyzed intramolecular Heck cyclization of N-(2-iodo-aryl) acrylamide with 2-methyl-2-phenylmalononitrile was developed to give oxindoles with good enantioselectivities. We found that utilizing such an electrophilic cyanation reagent could tackle the deleterious effect of the coordinative cyanide ion in the asymmetric alkene arylcyanation.

Nickel-catalyzed regio- and diastereoselective hydroarylative and hydroalkenylative cyclization of 1,6-dienes.

An unprecedented nickel-catalyzed hydroarylative and hydroalkenylative cyclization of unsymmetrically substituted 1,6-dienes with organoboronic acid was developed by using MeOH as the hydrogen source and employing commercially available Ni(η2-1,5-cyclooctadiene)2 as the catalyst. A series of biologically interesting cyclic products were afforded in moderate to excellent yields with high regio- and diastereoselectivities.

Selective catalytic two-step process for ethylene glycol from carbon monoxide.

Upgrading C1 chemicals (for example, CO, CO/H2, MeOH and CO2) with C-C bond formation is essential for the synthesis of bulk chemicals. In general, these industrially important processes (for example, Fischer Tropsch) proceed at drastic reaction conditions (>250 °C; high pressure) and suffer from low selectivity, which makes high capital investment necessary and requires additional purifications. Here, a different strategy for the preparation of ethylene glycol (EG) via initial oxidative coupling and subsequent reduction is presented. Separating coupling and reduction steps allows for a completely selective formation of EG (99%) from CO. This two-step catalytic procedure makes use of a Pd-catalysed oxycarbonylation of amines to oxamides at room temperature (RT) and subsequent Ru- or Fe-catalysed hydrogenation to EG. Notably, in the first step the required amines can be efficiently reused. The presented stepwise oxamide-mediated coupling provides the basis for a new strategy for selective upgrading of C1 chemicals.