Hydrocarboxylation of Terminal Alkenes in Supercritical Carbon Dioxide

Pd-Catalyzed Regioselective Branched Hydrocarboxylation of Terminal Olefins with Formic Acid

A regioselective Pd-catalyzed hydrocarboxylation of terminal olefins with HCOOH is described. A wide variety of branched carboxylic acids can readily be obtained with high regioselectivities under mild reaction conditions. The reaction is operationally simple and requires no handling of toxic CO. The ligand and LiCl are important factors for reaction reactivity and selectivity.

Photophysical Properties of Simple Palladium(0) Complexes Bearing Triphenylphosphine Derivatives

Pd(0) complexes with monodentate phosphine ligands, [Pd(P)_n] (n = 3, 4), are well-known catalysts. However, the nature of the Pd(0) complex, especially the basic photophysical properties of the Pd(0) complexes, has not been extensively explored. In this work, we measured the general photophysical properties and crystal structures of Pd(0)-bearing PPh₃ derivatives in the solid state and in solution. In the solid state, four-coordinated Pd(0) complexes exhibited blue-yellow emission. On the other hand, three-coordinated Pd(0) complexes displayed yellow-orange emission. In solution, orange emission of three-coordinated complexes was observed, and prompt fluorescence was detected using time-resolved emission spectroscopy, which suggests a thermally activated delayed fluorescence mechanism. Density functional theory (DFT) and time-dependent DFT calculations show that the difference in the transition mechanism between the [Pd(PPh₃)₄] and [Pd(PPh₃)₃] complexes explains the different emission colors. The emitting states of both complexes have metal-to-ligand charge-transfer character, but the metal-centered d → p transition is considerably incorporated for emission of the tris complex.

Construction of All-Carbon Chiral Quaternary Centers through CuI -Catalyzed Enantioselective Reductive Hydroxymethylation of 1,1-Disubstituted Allenes with CO2

A catalytic enantioselective construction of all-carbon chiral quaternary centers through reductive hydroxymethylation of 1,1-disubstituted allenes with CO₂ has been developed. In the presence of a copper/Mandyphos catalyst, CO₂ is transformed into an alcohol oxidation level by an asymmetric reductive C-C bond formation with allenes by using hydrosilane (HSi(OMe)₂ Me) as a reductant. The resulting chiral homoallylic alcohols are versatile synthetic intermediates and can be conveniently converted into a variety of useful chiral chemicals.

An easy access to carboxylic acids via Pd-catalyzed hydrocarboxylation of olefins with HCOOLi as a CO surrogate under mild conditions

This paper describes an easy access to carboxylic acids via Pd-catalyzed hydrocarboxylation of olefins with HCOOLi and Ac₂O under mild conditions without using external CO gas.

Carboxylic acid derivatives via catalytic carboxylation of unsaturated hydrocarbons: whether the nature of a reductant may determine the mechanism of CO2incorporation?

Advances and recent breakthroughs in catalytic synthesis of carboxylic acids and their derivatives starting from unsaturated hydrocarbons are discussed.

An atom-economic approach to carboxylic acids via Pd-catalyzed direct addition of formic acid to olefins with acetic anhydride as a co-catalyst

An effective Pd-catalyzed hydrocarboxylation of olefins using formic acid with acetic anhydride as a co-catalyst is described.