Robert McDonald

Cu-catalyzed domino N / O -arylation of triiodoarenes with primary amides enables regioselective access to 7-iodobenzo[ d ]oxazoles in high yields; docking and MD studies identify 7g and 7e as promising, stable ER _β -binding scaffolds for future study.

This study reports that the well-known Co(III) precursor Co(η⁵-Cp*)I₂(CO) (1) is an effective precatalyst for dehydrocoupling reactions of phosphines. Reaction monitoring by NMR, complemented by ESI-MS and EPR, suggests that Co(III) complexes containing secondary and primary phosphine ligands play an important role in this catalysis but that redox chemistry is also facile for these complexes, resulting in paramagnetic species. Representative examples of the mono(phosphine) complexes Co(η⁵-Cp*)I₂(PR₂H) (2) and Co(η⁵-Cp*)I₂(PRH₂) (4) and bis(phosphine) complexes [Co(η⁵-Cp*)I(PR₂H)₂] I (3) have been prepared. The characterization of these complexes through structural, computational, spectroscopic, and electrochemical analysis is reported and serves as a foundation for considering their mechanistic significance in the observed catalytic dehydrocoupling chemistry.

A direct and highly regioselective method for synthesizing 2,6-diiodophenylethanol is presented. In silico analysis shows compounds 7a, 7p, 7t, and 7z interact favourably with IDO/TDO receptors, highlighting their unmatched anticancer potential.

We report a general method for the desymmetrization of 6,13-pentacenequinone to access ethynylated pentacene ketones, namely, 13-hydroxy-13-(ethynylated)pentacene-6(13H)-ones. These pentacene ketones ("pentacenones") serve as divergent intermediates to unsymmetrically 6,13-disubstituted pentacenes, commonly used for studying singlet fission processes and charge transport phenomena in organic field effect transistors. We report a synthetic method to access pentacenones, which utilizes a precipitation/crystallization from the crude mixture to enable facile purification on a multigram scale. X-ray crystallographic analysis of the pentacenones reveals key noncovalent interactions that contribute to the crystallization, specifically, hydrogen bonding between the ketone and alcohol functional groups as well as pi-pi-stacking and dipole-dipole interactions.

Treating [Ru(PPh₃)₃Cl₂] with the amine 2-picolylamine (Picam) ligand in a 1:1 molar ratio, the Ru(II) complex trans-Ru(PPh₃)₂(Picam)Cl₂ (1) is obtained in methylene chloride and can be isolated as a pure solid compound. The single-crystal structure of 1 was determined by X-ray crystallography. The geometry at the Ru metal center is a distorted octahedral environment with a trans arrangement of the two chlorides. A trans effect of the bond lengths was observed within the structure. Similarly, treating [Ru(PPh₃)₃Cl₂] with 1:1:1 molar ratios of 2-picolylamine (Picam) and 1,1′-bis(diphenylphosphine)ferrocene (DPPF) ligands yielded the Ru(II) complex trans-Ru(DPPF)(Picam)Cl₂ (2). In identical conditions, the homogeneous hydrogen transfer catalytic reactivity of complexes 1 and 2 has been tested in a basic 2-propanol solution and they indicate different catalytic activity. It was discovered that monodentate and bidentate phosphine ligands of Ru(II) complexes, as well as cis- and trans-chloro configuration display different catalytic properties from our experimental data, in agreement with literature data. Based on DFT calculations, the relative molecular catalytic reactivity of all available experimental data is understood from the relative calculated molecular energy.

Three oxygen donor gallium(III) halide complexes, [GaX₃(O=P(TMP)₃] (TMP = trimethoxylphenyl and X = Cl⁻ (1), Br⁻ (2) and I⁻ (3)), are prepared by oxidation in mixed solvents from their phosphine adducts of [GaX₃(P(TMP)₃]. Three crystalline compounds are obtained from the solutions and their crystal structures are determined in the solid state. It is rare to generate a crystalline phase for metal–adduct compounds of this bulky ligand; in this paper, three new crystal structures are presented.

We report a re-examination of Trofimenko’s original protocol for the preparation of the acid form of his hydrotris(pyrazolyl)borates, H(TpR,R′), by the treatment of M(TpR,R′) with glacial acetic acid. It is concluded that the protocol is effective as long as the 3-substituent of the pyrazolyl moiety is sufficiently bulky to provide steric protection to the acidic N–H proton. The solid-state structure of H(TptBu,Me), the acid form of the popular TptBu,Me ligand is also presented.

An efficient and unprecedented synthesis of 2,3-diiodinated N-aryl carbamate derivatives through highly regioselective Ullmann-type C–N arylation reactions of 5-substituted-1,2,3-triiodobenzenes and primary carbamates is described. Remarkably, the amination reactions proceeded exclusively at the terminal positions, the less sterically hindered, and the most regioactive positions. The highest yields were isolated from a combination between electron poor 1,2,3-triiodoarenes and ethyl carbamates. The optimized conditions were found to be suitable for many functional groups. This report discloses the first and unprecedented method to make 2,3-diiodinated N-aryl carbamates that is efficient, general in scope, highly regioselective and gives truly remarkable precursors for other transformations.