Half-Sandwich Iridium Complexes with Hydrazone Ligands: Synthesis and Catalytic Activity in N-Alkylation of Anilines or Nitroarenes with Alcohols via Hydrogen Autotransfer.

Here, we synthesize a series of hydrazone-based N,O-chelate half-sandwich iridium complexes through a facile route. All air-stable iridium complexes show high catalytic activity in N-alkylation of a broad scope of aniline derivatives and alcohols with liberating water as the sole byproduct. This reaction provides a smooth route to synthesize diverse monoalkylated amines in good to excellent yields at moderate temperature with a low catalyst loading. Moreover, the challenging N-alkylation process using nitroarene substrates as coupling partners is also carried out in this catalytic system. The mechanistic study shows that the present iridium catalysis process proceeds through a hydrogen borrowing mechanism. All iridium(III) complexes 1-4 are characterized by infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis.

[A review of clinical specifications of Scutellariae Radix pieces in ancient and modern literature].

Scutellariae Radix is a commonly used Chinese medicinal first recorded in the Shennong's Classic of Materia Medica. In the ancient books of traditional Chinese medicine(TCM), Scutellariae Radix is used in two specifications, solid one(Ziqin) and hollow one(Kuqin). In the current rules and regulations of Chinese medicine, Scutellariae Radix is used without the specific requirements for the specifications applied. To clarify the evolution of Scutellariae Radix specifications and analyze the current specifications of Scutellariae Radix pieces, the present study reviews the Scutellariae Radix from ancient literature, modern rules and regulations, and differences between Ziqin and Kuqin in composition, efficacy, and transformation mechanism. According to the research on ancient books, Kuqin is effective in clearing the fire of the upper energizer, and Ziqin in purging the heat of the lower energizer. Modern studies have revealed that Kuqin and Ziqin are significantly different in chemical components, and Ziqin and Kuqin target the colon and lung, respectively, which are consistent with the relevant records in ancient books. The review study suggests that the two specifications of Scutellariae Radix are reasonable since they can facilitate the precise treatment of Scutellariae Radix.