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"Through space" metal/hydrogen shift constitutes one of the efficient elementary step in organometallic chemistry to achieve selective remote C−H bond functionalization. Compared with the relatively extensive exploration on 1,4‐palladium migration, the processes on corresponding 1,5‐palladium translocation are far less explored. Based on our understanding on related research areas, we summarized the advances achieved in remote C−H bond activation through a key step of 1,5‐palladium migration in this minireview. The background, reaction scope, and more importantly, the mechanistic rationale of each transformation was discussed. We hope by reading through this minireview, one could get a general perspective on direct C−H bond activation via 1,5‐palladium/hydrogen shift, and could understand why such a process is less common when compared with the process going through 1,4‐palladium/hydrogen migration, and eventually could be inspired to develop practical ways for the synthesis of valuable molecules, which could not be prepared easily through other traditional approaches. [ABSTRACT FROM AUTHOR]

Abstract: Trametenolic acid B (TAB), the bioactive component in the Trametes lactinea (Berk.) Pat, was reported to possess cytotoxic activities and thrombin inhibiting effects. This study was performed to investigate the effects of TAB on H+/K+-ATPase and gastric cancer. The H+/K+-ATPase inhibitory activity was determined by gastric parietal cells. Compared to the normal control group, TAB (10, 20, 40 and 80μg/mL) inhibited the H+/K+-ATPase activity by 15.97, 16.96, 24.86 and 16.25%, respectively. In the study, 36 Kunming mice were randomly divided into six groups: control, model, TAB-L (TAB, 5mg/kg/day, i.g.), TAB-M (TAB, 20mg/kg/day, i.g.), TAB-H (TAB, 40mg/kg/day, i.g.) and omeprazole (OL, 10mg/kg/day, i.g.). All mice except the control group were administrated with anhydrous alcohol (5.0mL/kg, i.g.) for induced gastric-ulcer 1h after the 5th day. At the same time, the control mice were given the same volume of physiological saline. After 4h, TAB was evaluated for H+/K+-ATPase inhibitory activities of ulcerative gaster, gastric ulcer index and ulcer inhibition. In vitro, the anti-proliferation effect of TAB to gastric cancer cell (HGC-27) in acid environment was detected by MTT, and the apoptosis morphological changes were also observed by Hoechst 33258 dye assay. The results indicated that TAB inhibited moderately H+/K+-ATPase activity in vitro. Compared to the model group, TAB showed anti-ulcer effects in gastric tissue with the dosages of 20 and 5mg/kg in vivo. Apart from that, TAB could selectively inhibit gastric cancer cell viability and reduce cell apoptosis against HGC-27 cells at low doses in acid environment. [Copyright &y& Elsevier]

"Through space" palladium/hydrogen shift is an efficient strategy to achieve selective functionalization of a specific remote C-H bond. Compared with relatively extensive exploited 1,4-palladium migration process, the relevant 1,5-Pd/H shift was far less investigated. We herein report a novel 1,5-Pd/H shift pattern between a vinyl and an acyl group. Through the pattern, rapid access to 5-membered-dihydrobenzofuran and indoline derivatives has been achieved. Further studies have unveiled an unprecedented trifunctionalization (vinylation, alkynylation and amination) of a phenyl ring through 1,5-palladium migration relayed decarbonylative Catellani type reaction. A series of mechanistic investigations and DFT calculations have provided insights into the reaction pathway. Notably, it was unveiled that the 1,5-palladium migration in our case prefers a stepwise mechanism involving a Pd IV intermediate., (© 2023 Wiley-VCH GmbH.)

Here, we describe a highly selective Pd-catalyzed C(sp 3 )-H biarylation of 2-methylbenzaldehydes using cyclic diaryliodonium salts as arylation reagents. The key strategy is the employment of tert -leucine as a bidentate transient directing group for the proximity-driven metalation to achieve reactivity and selectivity in C-H activation. Various functionalized biaryls bearing both aldehyde and iodine functional groups were prepared successfully, which could be further transformed into a wide range of compounds with potential applications in pharmaceutical chemistry and materials science.

In the title compound, C(15)H(24)O(4), the six-membered ring shows a distorted chair conformation and the five-membered ring adopts an envelope conformation with the C atom bearing the methyl and OH groups as the flap. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into chains running along the a-axis direction.