Quinone-mediated hydrogen anode for non-aqueous reductive electrosynthesis.

Electrochemical synthesis can provide more sustainable routes to industrial chemicals. Electrosynthetic oxidations may often be performed 'reagent-free', generating hydrogen (H) derived from the substrate as the sole by-product at the counter electrode. Electrosynthetic reductions, however, require an external source of electrons.

Benzoquinone Cocatalyst Contributions to DAF/Pd(OAc)-Catalyzed Aerobic Allylic Acetoxylation in the Absence and Presence of a Co(salophen) Cocatalyst.

Palladium(II)-catalyzed allylic acetoxylation has been the focus of extensive development and investigation. Methods that use molecular oxygen (O) as the terminal oxidant typically benefit from the use of benzoquinone (BQ) and a transition-metal (TM) cocatalyst, such as Co(salophen), to support oxidation of Pd during catalytic turnover. We previously showed that Pd(OAc) and 4,5-diazafluoren-9-one (DAF) as an ancillary ligand catalyze allylic oxidation with O in the absence of cocatalysts.

Multichannel gas-uptake/evolution reactor for monitoring liquid-phase chemical reactions.

The design of a headspace pressure-monitoring reactor for measuring the uptake/evolution of gas in gas-liquid chemical transformations is described. The reactor features a parallel setup with ten-reactor cells, each featuring a low working volume of 0.2-2 ml, a pressure capacity from 0 to 150 PSIa, and a high sensitivity pressure transducer.

Experimental and Computational Investigation of the Aerobic Oxidation of a Late Transition Metal-Hydride.

The rational development of homogeneous catalytic systems for selective aerobic oxidations of organics has been hampered by the limited available knowledge of how oxygen reacts with important organometallic intermediates. Recently, several mechanisms for oxygen insertion into late transition metal-hydride bonds have been described. Contributing to this nascent understanding of how oxygen reacts with metal-hydrides, a detailed mechanistic study of the reaction of oxygen with the Ir hydride complex (Phebox)Ir(OAc)(H) () in the presence of acetic acid, which proceeds to form the Ir complex (Phebox)Ir(OAc)(OH) (), is described.

Operando Spectroscopic and Kinetic Characterization of Aerobic Allylic C-H Acetoxylation Catalyzed by Pd(OAc)/4,5-Diazafluoren-9-one.

Allylic C-H acetoxylations are among the most widely studied palladium(II)-catalyzed C-H oxidation reactions. While the principal reaction steps are well established, key features of the catalytic mechanisms are poorly characterized, including the identity of the turnover-limiting step and the catalyst resting state. Here, we report a mechanistic study of aerobic allylic acetoxylation of allylbenzene with a catalyst system composed of Pd(OAc) and 4,5-diazafluoren-9-one (DAF).

Dichlorido(η(6)-p-cymene)(eth-oxy-diphenyl-phosphane)ruthenium(II).

The title compound, [RuCl2(C10H14)(C14H15OP)], is an Ru(II) complex in which an η(6)-p-cymene ligand, two chloride anions and the P atom of an ethoxydiphenylphosphane ligand form a piano-stool coordination environment about the central Ru(II) atom.

2,2'-(Propane-2,2-di-yl)dibenzothia-zole.

The two symmetry-independent mol-ecules in the asymmetric unit of the title compound, C(17)H(14)N(2)S(2), have similar geometry; the dihedral angles between the least-squares planes of the benzothia-zole groups in the two mol-ecules are 83.93 (3) and 81.26 (3)°.

Investigation of the reactivity of Pt phosphinito and molybdocene nitrile hydration catalysts with cyanohydrins.

Aldehyde- and ketone-derived cyanohydrins were reacted with the nitrile hydration catalysts [PtCl(PR(2)OH){(PR(2)O)(2)H}] (1) and Cp(2)Mo(OH)(OH(2))(+) (2) under a variety of hydration reaction conditions. In general, the cyanohydrins were hydrated to the amides rather slowly using these catalysts, but no subsequent hydrolysis of the amide products occurred. Catalyst 2 was much less reactive than catalyst 1, showing at best trace amounts of amide product.