In contrast to the wealth of asymmetric transformations for generating central chirality from alkyl radicals, the enantiocontrol over the allenyl radicals for forging axial chirality represents an ...uncharted domain. The challenge arises from the unique elongated linear configuration of the allenyl radicals that necessitates the stereo‐differentiation of remote motifs away from the radical reaction site. We herein describe a copper‐catalyzed asymmetric radical 1,4‐carboalkynylation of 1,3‐enynes via the coupling of allenyl radicals with terminal alkynes, providing diverse synthetically challenging tetrasubstituted chiral allenes. A chiral N,N,P‐ligand is crucial for both the reaction initiation and the enantiocontrol over the highly reactive allenyl radicals. The reaction features a broad substrate scope, covering a variety of (hetero)aryl and alkyl alkynes and 1,3‐enynes as well as radical precursors with excellent functional group tolerance.
A copper‐catalyzed asymmetric radical 1,4‐carboalkynylation of 1,3‐enynes is realized, providing diverse tetrasubstituted chiral allenes. The utilization of the copper/chiral N,N,P‐ligand is crucial for the enantiocontrol over the allenyl radicals, which is difficult due to their elongated linear configuration that necessitates the stereo‐differentiation of remote motifs away from the reaction site.
We have described a copper-catalyzed radical 1,2-carbotrifluoromethylselenolation of alkenes using the readily available alkyl halides and (Me
N)SeCF
salt. Critical to the success is the use of a ...proline-based N,N,P-ligand to enhance the reducing capability of copper for easy conversion of diverse alkyl halides to the corresponding radicals via a single-electron transfer process. The reaction features a broad substrate scope, including various mono-, di-, and trisubstituted alkenes with many functional groups.
A copper-catalyzed intermolecular three-component asymmetric radical 1,2-carboalkynylation of alkenes has been developed, providing straightforward access to diverse chiral alkynes from readily ...available alkyl halides and terminal alkynes. The utilization of a cinchona alkaloid-derived multidentate N,N,P-ligand is crucial for the efficient radical generation from mildly oxidative precursors by copper and the effective inhibition of the undesired Glaser coupling side reaction. The substrate scope is broad, covering (hetero)aryl-, alkynyl-, and aminocarbonyl-substituted alkenes, (hetero)aryl and alkyl as well as silyl alkynes, and tertiary to primary alkyl radical precursors with excellent functional group compatibility. Facile transformations of the obtained chiral alkynes have also been demonstrated, highlighting the excellent complementarity of this protocol to direct 1,2-dicarbofunctionalization reactions with C(sp 2/sp 3)-based reagents.
In contrast to the wealth of asymmetric transformations for generating central chirality from alkyl radicals, the enantiocontrol over the allenyl radicals for forging axial chirality represents an ...uncharted domain. The challenge arises from the unique elongated linear configuration of the allenyl radicals that necessitates the stereo‐differentiation of remote motifs away from the radical reaction site. We herein describe a copper‐catalyzed asymmetric radical 1,4‐carboalkynylation of 1,3‐enynes via the coupling of allenyl radicals with terminal alkynes, providing diverse synthetically challenging tetrasubstituted chiral allenes. A chiral N,N,P‐ligand is crucial for both the reaction initiation and the enantiocontrol over the highly reactive allenyl radicals. The reaction features a broad substrate scope, covering a variety of (hetero)aryl and alkyl alkynes and 1,3‐enynes as well as radical precursors with excellent functional group tolerance.
A copper‐catalyzed asymmetric radical 1,4‐carboalkynylation of 1,3‐enynes is realized, providing diverse tetrasubstituted chiral allenes. The utilization of the copper/chiral N,N,P‐ligand is crucial for the enantiocontrol over the allenyl radicals, which is difficult due to their elongated linear configuration that necessitates the stereo‐differentiation of remote motifs away from the reaction site.
We have described a copper-catalyzed radical 1,2-carbotrifluoromethylselenolation of alkenes using the readily available alkyl halides and (Me4N)SeCF3 salt. Critical to the success is the use of a ...proline-based N,N,P-ligand to enhance the reducing capability of copper for easy conversion of diverse alkyl halides to the corresponding radicals via a single-electron transfer process. The reaction features a broad substrate scope, including various mono-, di-, and trisubstituted alkenes with many functional groups.
To the Editor： Capillary hemangioma （CH）, as a benign tumor of blood vessels, commonly appears in the skin or other superficial soft tissue throughout the body among pediatric population. Spinal ...intradural extramedullary capillary hemangioma （IDEMCH） is rare. According to the recent review by Bouali et al., only forty cases have been reported in English literature,N and the size of the existing masses are generally around one vertebral length on the magnetic resonance imaging （MRI）. In this paper, we report the first case of CH in the cauda equina that extends over two vertebral bodies, and discuss the diagnosis and treatment associated with such disorder.
The shortage of cultivated land resources in coastal areas of Zhejiang province can be effectively resolved by improving coastal saline-alkali soil. In this study, the effects of different materials ...on salinization and fertility of coastal saline-alkali soil in Zhejiang province were evaluated through column leaching experiment. The results revealed that the soil pH were significantly reduced by 0.64 units in the treatments of PA (2% polymaleic anhydride) and DF2 (1% desulfurized gypsum +1% fly ash) compared to CK. The BC (2% biochar) treatment has significantly reduced soil conductivity and salt content by 84.8% and 93.7% compared to CK, respectively. The soil sodium adsorption ratio and alkalinity value of DG (2% desulfurized gypsum) treatment was the lowest, which were 77.7% and 74.0% lower than that of CK, respectively. The contents of available nitrogen, available phosphorus, available potassium, and organic matter were highly enhanced in the treatments of DF2, PA, DB3 (0.5% desulfurized gypsum +1.5% biochar), and FA (2% fly ash), which were 101.7%, 54.1%, and 54.4% higher than CK, respectively. Furthermore, treatments of DF2 and DB3 were significantly improved activities of urease and alkaline phosphatase in the soil by 275.3% and 171.7%, respectively, compared to CK. The treatment of PA had increased the activities of catalase and sucrase in the soil by 67.9% and 26.4%, respectively, compared to CK. The treatments of DB3, DF2, and DP3 (0.5% desulphurized gypsum +1.5% polymaleic anhydride) had shown great potential to improve soil salinization characteristics and enhance soil fertility, which was conducive for sustainable development plan of coastal saline-alkali soil of Zhejiang Province.
The regenerative potential of injured axons displays considerable heterogeneity. However, the molecular mechanisms underlying the heterogeneity have not been fully elucidated. Here, we establish a ...method that can separate spinal motor neurons (spMNs) with low and high regenerative capacities and identify a set of transcripts revealing differential expression between two groups of neurons. Interestingly, oligodendrocyte transcription factor 1 (Olig1), which regulates the differentiation of various neuronal progenitors, exhibits recurrent expression in spMNs with enhanced regenerative capabilities. Furthermore, overexpression of Olig1 (Olig1 OE) facilitates axonal regeneration in various models, and down-regulation or deletion of Olig1 exhibits an opposite effect. By analyzing the overlapped differentially expressed genes after expressing individual Olig factor and functional validation, we find that the role of Olig1 is at least partially through the neurite extension factor 1 (Nrsn1). We therefore identify Olig1 as an intrinsic factor that promotes regenerative capacity of injured axons.
Display omitted
•Transcriptomic profiling reveals heterogeneity in axon regeneration after PNS injury•Recurrence expression of Olig1 marks regeneration-competent spinal motor neurons•Olig1 knockdown attenuates PNS regeneration and mTOR signaling•Olig1 promotes axon regeneration through Nrsn1
Fu et al. develop a method that can isolate spinal motor neurons with different regenerative capability after injury and reveals factors with differential expression. They focus on the functional analysis of Olig1, a transcription factor that determines early neural patterning, and reveal its effects on axonal regeneration in various models.
