Ru-Catalyzed aromatic C-H bond activation and functionalization have emerged as important topics because they have resulted in remarkable progress in organic synthesis. Both experimental and theoretical studies of their mechanisms are important for the design of new synthetic methodologies. In this review, a mechanistic view of the Ru-mediated C-H bond cleavage step is first given to reveal the C-H bond activation modes, including oxidative addition, metathesis and base-assisted deprotonation. In this process, directing groups play an important role in determining the reactivity of the C-H bond. The C-H bond activation generally leads to the formation of a Ru-C bond, which is further functionalized in the subsequent steps. The mechanisms of Ru-catalyzed arylation, alkylation, and alkenylation of arenes are summarized, and these transformations can be categorized into cross-coupling with electrophiles or oxidative coupling with nucleophiles. In addition, the mechanism of ortho-ruthenation-enabled remote C-H bond functionalization is also discussed.

Bacterial communities that enrich in high‐temperature Daqu are important for the Chinese maotai‐flavor liquor brewing process. However, the bacterial communities in three different types of high‐temperature Daqu (white Daqu, black Daqu, and yellow Daqu) are still undercharacterized. In this study, the bacterial diversity of three different types of high‐temperature Daqu was investigated using Illumina MiSeq high‐throughput sequencing. The bacterial community of high‐temperature Daqu is mainly composed of thermophilic bacteria, and seven bacterial phyla along with 262 bacterial genera were identified in all 30 high‐temperature Daqu samples. Firmicutes, Actinobacteria, Proteobacteria, and Acidobacteria were the dominant bacterial phyla in high‐temperature Daqu samples, while Thermoactinomyces, Staphylococcus, Lentibacillus, Bacillus, Kroppenstedtia, Saccharopolyspora, Streptomyces, and Brevibacterium were the dominant bacterial genera. The bacterial community structure of three different types of high‐temperature Daqu was significantly different (p < .05). In addition, the results of microbiome phenotype prediction by BugBase and bacterial functional potential prediction using PICRUSt show that bacteria from different types of high‐temperature Daqu have similar functions as well as phenotypes, and bacteria in high‐temperature Daqu have vigorous metabolism in the transport and decomposition of amino acids and carbohydrates. These results offer a reference for the comprehensive understanding of bacterial diversity of high‐temperature Daqu.

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