New method for the preparation of dibenzo[b, f][1,4]thiazepines

Electrophotocatalytic hydrogenation of imines and reductive functionalization of aryl halides

The open-shell catalytically active species, like radical cations or radical anions, generated by one-electron transfer of precatalysts are widely used in energy-consuming redox reactions, but their excited-state lifetimes are usually short. Here, a closed-shell thioxanthone-hydrogen anion species (3), which can be photochemically converted to a potent and long-lived reductant, is generated under electrochemical conditions, enabling the electrophotocatalytic hydrogenation. Notably, TfOH can regulate the redox potential of the active species in this system. In the presence of TfOH, precatalyst (1) reduction can occur at low potential, so that competitive H2 evolution can be inhibited, thus effectively promoting the hydrogenation of imines. In the absence of TfOH, the reducing ability of the system can reach a potency even comparable to that of Na0 or Li0, thereby allowing the hydrogenation, borylation, stannylation and (hetero)arylation of aryl halides to construct C-H, C-B, C-Sn, and C-C bonds.

Review of the Syntheses and Activities of Some Sulfur-Containing Drugs

Background:

Sulfur-containing compounds represent an important class of chemical compounds due to their wide range of biological and pharmaceutical properties. Moreover, sulfur-containing compounds may be applied in other fields, such as biological, organic, and materials chemistry. Several studies on the activities of sulfur compounds have already proven their anti-inflammatory properties and use to treat diseases, such as Alzheimer’s, Parkinson’s, and HIV. Moreover, examples of sulfur-containing compounds include dapsone, quetiapine, penicillin, probucol, and nelfinavir, which are important drugs with known activities.

Objective:

This review will focus on the synthesis and application of some sulfur-containing compounds used to treat several diseases, as well as promising new drug candidates.

Results:

Due to the variety of compounds containing C-S bonds, we have reviewed the different synthetic routes used toward the synthesis of sulfur-containing drugs and other compounds.

Iridium-catalyzed asymmetric hydrogenation of dibenzo[b,f][1,4]thiazepines

Highly enantioselective hydrogenation of substituted dibenzo[b,f][1,4]thiazepines was achieved with up to 96 % ee (enantiomeric excess) using [Ir(COD)Cl]2/(R)-SynPhos complex as catalyst in the presence of iodine. This method provides an efficient access to optically active 11-substituted-10,11-dihydrodibenzo[b,f][1,4]thiazepines.