Palladium-catalyzed Regiodivergent Decarboxylative Hydrothiocarbonylation of Vinylarenes using Oxalic Acid Monothioesters

Pd-Catalyzed Regioselective Hydrocarboxylation of Alkyl Terminal Olefins with Oxalic Acid

A Pd-catalyzed regioselective hydrocarboxylation of alkyl terminal olefins with oxalic acid is described. A wide variety of linear carboxylic acids can be readily obtained in good yields and high l/b (linear/branched) ratios with Pd2(dba)3 and (p-ClPh)3P under mild conditions. The reaction process is operationally simple and requires no handling of toxic CO. In addition, branched carboxylic acids can also be formed in good regioselectivities with PdCl2 and (2',6'-dimethoxy-[1,1'-biphenyl]-2-yl)diphenylphosphine (L1).

Pd-Catalyzed Regiodivergent Hydrocarboxylation of Olefins with Oxalic Acid: A Remarkable Effect of the Counteranion on Regioselectivity

A regioselective Pd-catalyzed hydrocarboxylation of vinyl arenes with oxalic acid is described. A wide variety of either linear or branched carboxylic acids can be readily obtained with high regioselectivities under mild reaction conditions. The reaction process is operationally simple and requires no handling of toxic CO. Besides the ligand, the counteranion of the Pd catalyst system plays an important role in the regioselectivity.

Visible Light-Accelerated Palladium-Catalyzed Thiocarbonylation Using Oxalic Acid Monothioester with Aryl/Alkenyl Sulfonium Salts

Herein, we present a decarboxylative thiocarbonylation of aryl and alkenyl sulfonium salts with oxalic acid monothioethers (OAMs), which can be achieved by visible light-accelerated palladium catalysis. Sulfonium salts are widely available, and OAM is an easily accessible and stored reagent; this mild reaction method can also be used for the synthesis of different types of thioester compounds. The reaction represents a new application of visible light-accelerated palladium catalysis in catalytic decarboxylative cross-couplings.

Orthogonal Access to α-/β-Branched/Linear Aliphatic Amines by Catalyst-Tuned Regiodivergent Hydroalkylations

Linear, α-branched, and β-branched aliphatic amines are widespread in pharmaceuticals, agrochemicals, and fine chemicals. Thus, the development of direct and efficient methods to these structures in a tunable manner is highly desirable yet challenging. Herein, a catalyst-controlled synthesis of α-branched, β-branched and linear aliphatic amines from Ni/Co-catalyzed regio- and site-selective hydroalkylations of alkenyl amines with alkyl halides is developed. This catalytic protocol features the reliable prediction and control of the coupling position of alkylation to provide orthogonal access to α-branched, β-branched and linear alkyl amines from identical starting materials. This platform unlocks orthogonal reactivity and selectivity of nickel hydride and cobalt hydride chemistry to catalytically repurpose three types of alkyl amines under mild conditions.