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Precisely controlling the product selectivity of a reaction is an important objective in organic synthesis. α‐Ketoamides are vital intermediates in chemical transformations and privileged motifs in numerous drugs, natural products, and biologically active molecules. The selective synthesis of α‐ketoamides from feedstock chemicals in a safe and operationally simple manner under mild conditions is a long‐standing catalysis challenge. Herein, an unprecedented TBD‐switched Pd‐catalyzed double isocyanide insertion reaction for assembling ketoamides in aqueous DMSO from (hetero)aryl halides and pseudohalides under mild conditions is reported. The effectiveness and utility of this protocol are demonstrated by its diverse substrate scope (93 examples), the ability to late‐stage modify pharmaceuticals, scalability to large‐scale synthesis, and the synthesis of pharmaceutically active molecules. Mechanistic studies indicate that TBD is a key ligand that modulates the Pd‐catalyzed double isocyanide insertion process, thereby selectively providing the desired α‐ketoamides in a unique manner. In addition, the imidoylpalladium(II) complex and α‐ketoimine amide are successfully isolated and determined by X‐ray analysis, confirming that they are probable intermediates in the catalytic pathway. [ABSTRACT FROM AUTHOR]

Trifluoromethyl cationic carbyne (CF 3 C + :) possessing dual carbene-carbocation behavior emulated as trifluoromethyl metal-carbynoid (CF 3 C + =M) has not been explored yet, and its reaction characteristics are unknown. Herein, a novel α-diazotrifluoroethyl sulfonium salt was prepared and used in Rh-catalyzed three-component [2+1+2] cycloadditions for the first time with commercially available N-fused heteroarenes and nitriles, yielding a series of imidazo[1,5-a] N-heterocycles that are of interest in medicinal chemistry, in which the insertion of trifluoromethyl Rh-carbynoid (CF 3 C + =Rh) into C=N bonds of N-fused heteroarenes was involved. This strategy demonstrates synthetic applications in late-stage modification of pharmaceuticals, construction of CD 3 -containing N-heterocycles, gram-scale experiments, and synthesis of phosphodiesterase 10A inhibitor analog. These highly valuable and modifiable imidazo[1,5-a] N-heterocycles exhibit good antitumor activity in vitro, thus demonstrating their potential applications in medicinal chemistry., (© 2024 Wiley-VCH GmbH.)

Objective: The study was conducted to evaluate the stability of commercial coated lipase (CT-LIP) in vitro ., Methods: The capsules were tested under different conditions with a range of temperature, pH, dry heat treatment and steaming treatment, simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) in this work, respectively. Free lipase (uncoated lipase, UC-LIP) was the control group. Lipase relative activities measured in various treatments were used as a reference frame to characterize the stability., Results: The lipase activities were decreased with increasing temperatures (p<0.05), and there was a markedly decline (p<0.01) in lipase comparative activities of UC-LIP at 80°C compared with CT-LIP group. Higher relative activities of lipase were observed in CT-LIP group compared with the free one under acidic ambient (pH 3 to 7) and an alkaline medium (pH 8 to 12). Residual lipase activities of CT-LIP group were increased (p<0.05) by 5.67% and 35.60% in dry heat and hydrothermal treatments, respectively. The lipase relative activity profile of CT-LIP was raised at first and dropped subsequently (p<0.05) compared with constantly reduced tendency of UC-LIP exposed to both SGF and SIF., Conclusion: The results suggest that the CT-LIP possesses relatively higher stability in comparison with the UC-LIP in vitro . The CT-LIP could retain the potential property to provide sustained release of lipase and thus improved its bioavailability in the gastrointestinal tract.