Hydrocarboxylation of alkynes with formic acid over multifunctional ligand modified Pd-catalyst with co-catalytic effect

Photocatalytic deuterocarboxylation of alkynes with oxalate

Herein, a catalytic photoredox-neutral strategy for alkyne deuterocarboxylation with tetrabutylammonium oxalate as the carbonyl source and D2O as the deuteration agent was described. For the first time, the oxalic salt acted as both the reductant and carbonyl source through single electron transfer and subsequential homolysis of the C-C bond. The strongly reductive CO2 radical anion species in situ generated from oxalate played significant roles in realizing the global deuterocarboxylation of terminal and internal alkynes to access various tetra- and tri-deuterated aryl propionic acids with high yields and deuteration ratios.

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).

Visible-light-promoted regioselective hydrocarboxylation of allenes with formate salt and CO2

Visible-light-promoted hydrocarboxylation of allenes with formate salt and CO2 was developed for the first time using commercially available [Ir(ppy)2(dtbbpy)]PF6 as a photocatalyst. This strategy provides an efficient and practical method to access β,γ-unsaturated linear carboxylic acids in moderate yields with complete regioselectivity.

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.