Griffith Zhu (lizardroast0)

Difluoromethyl-containing or propargylic stereocenter-bearing molecules find extensive application in pharmaceuticals and agrochemicals, with 12-functionalization of olefins serving as a crucial method for their simultaneous introduction. Terminal alkynes, when forming propargylic stereocenters, frequently necessitate the use of bases. Difluoromethylating agents with high reduction potentials, unfortunately, often decompose when subjected to basic conditions due to their acidity, whereas those with low reduction potentials, though stable, present difficulty in undergoing the desired single electron transfer (SET) reduction. By leveraging the linear relationship between reduction potential differences (E) and Hammett substituent constants (σ) for difluoromethyl aryl sulfones, we successfully addressed the discrepancy between the acidities and reduction potentials of difluoromethylating reagents. The first enantioselective difluoromethylation-alkynylation of olefins with difluoromethyl 4-chlorophenyl sulfone is reported herein, with high enantioselectivity exceeding 90% ee. The asymmetric fluoroalkylation-alkynylation reaction was further developed by the introduction of various fluoroalkyl sulfones, thus enabling efficient integration of trifluoromethyl, difluoroalkyl, difluorobenzyl, (benzenesulfonyl)-difluoromethyl, and monofluoromethyl groups into the product molecules. In terms of appearance, black-bone fowl differ substantially from ordinary broilers, and their nutritional properties are considered robust and substantial. Despite this, the metabolism of pharmaceutical agents in black-bone fowl is currently unclear. To ascertain the rate of trimethoprim and sulfachloropyridazine tissue residue elimination in Yugan black-bone fowl, a five-day regimen of oral administration at 4 mg/kg body weight per day for trimethoprim and 20 mg/kg body weight per day for sulfachloropyridazine was implemented, and withdrawal times were calculated. Samples of the following tissues (liver, kidney, muscle, and skin/fat) were collected at the stated time points after multiple oral administrations: 1, 3, 5, 7, 9, 16, 20, 30, and 40 days. Employing a novel LC-MS/MS method, the concentrations of trimethoprim and sulfachlorpyridazine were determined in target tissues. Broiler metabolism swiftly eliminated sulfachloropyridazine, resulting in no residue being found in any tissue three days post-treatment. Trimethoprim exhibits its highest concentration level in the skin and fat tissues of black-bone fowl, with a slow metabolic rate. The trimethoprim concentration in skin and fat, 40 days later, is still remarkably high at 1401580 grams per kilogram, a figure that exceeds the maximum residue limit. To guarantee consumer health, the withdrawal period for TMP in Yugan black-bone fowl should be 69 days. The classification of semiconductors as having either direct or indirect band gaps is predicated upon the comparative positioning of the top of the valence band and the bottom of the conduction band in the crystal momentum (k) space. The application of k as a quantum number to characterize band structure in quantum-confined nanocrystalline systems, whose behavior can make the distinction between direct and indirect gap semiconductors unclear, is a matter of ongoing discussion. Adjusting the x-value within bulk III-V semiconductor alloys, such as In1-xGaxP, enables a continuous shift in the band structure's energy gap, progressing from direct to indirect. The system's direct-to-indirect transition, when subjected to intense quantum confinement, remains unevaluated. This is largely due to the ongoing shortage of high-quality colloidal nanocrystal specimens. An optimized molten-salt In-to-Ga cation exchange protocol was central to this systematic investigation of ternary III-V nanocrystals, resulting in the production of exceptionally bright In1-xGaxP/ZnS core-shell particles with photoluminescence quantum yields surpassing 80%. To as