rhodiumiiicatalyzed32annulativecouplingbetweenoximesandelectrondeficientalkynes

Rhodium(III)-catalyzed coupling between ketoximes and alkynes via C–H activation and annulation typically followed the 4+2 selectivity to afford isoquinolines. By designing alkynes bearing a highly electron-withdrawing group and under substrate control, we have successfully switched the selectivity of the coupling between oximes and alkynes to the alternative 3+2 annulation, leading to the efficient synthesis of indenamines. This process features good regioselectivity for both substrates, high efficiency, broad substrate scope, and excellent functional group tolerance

rhodiumiiicatalyzed32annulativecouplingbetweenoximesandelectrondeficientalkynes

Rhodium(III)-catalyzed coupling between ketoximes and alkynes via C–H activation and annulation typically followed the 4+2 selectivity to afford isoquinolines. By designing alkynes bearing a highly electron-withdrawing group and under substrate control, we have successfully switched the selectivity of the coupling between oximes and alkynes to the alternative 3+2 annulation, leading to the efficient synthesis of indenamines. This process features good regioselectivity for both substrates, high efficiency, broad substrate scope, and excellent functional group tolerance

Economic Dispatch of Power Retailers: A Bi-Level Programming Approach via Market Clearing Price

For power retailers in a smart grid, it is necessary to design an economic dispatch method to maintain a balance between power supply and demand on the sale side as well as obtain better economic benefits. This study concentrates on the economic dispatch of the dominant retailer in a regional market. The dominant retailer is considered to be equipped with generator resources such as distributed photovoltaics (PV), wind turbines (WT), and microturbines (MT). As one retailer cannot exactly predict the market conditions of other retailers, the retail market is considered to be modeled as a dichotomous-market model consisting of the dominant retailer market and the other retailers market. As a result, a bi-level optimal dispatch model is proposed for the dominant power retailer based on the dichotomous-market model. In the proposed model, the outer problem aims to minimize the costs of purchases under time-of-use (TOU) price given in the market clearing process, while the inner problem is formulated to simulate the process of market clearing. Furthermore, the bi-level model is converted to a single-level model via the Karush–Kuhn–Tucker (KKT) conditions and eventually solved by employing the YALMIP toolbox with Gurobi solver. Finally, a case study is conducted to validate the effectiveness and adaptability of the proposed model, and the analysis of the variables is presented

Rhodium(III)-Catalyzed Mild Alkylation of (Hetero)Arenes with Cyclopropanols via C–H Activation and Ring Opening

The rhodium­(III)-catalyzed regioselective alkylation of (hetero)­arenes using cyclopropanols as a reactive and efficient coupling partner under oxidative conditions has been developed. This coupling occurred at room temperature via C–H activation of arenes and C–C cleavage of cyclopropanols. Various types of (hetero)­arenes (indolines, carbazole, tetrahydrocarbazole, pyrrole, thiophene, etc.) were all successfully reacted under the present conditions. This protocol provides the facile and efficient construction of C7-alkylated indoline scaffolds

Increased CO2 concentrations increasing water use efficiency and improvement PSII function of mulberry seedling leaves under drought stress

In this paper, the effects of different CO2 concentrations (400 and 800 μmol·mol−1) on photosynthetic gas exchange and chlorophyll fluorescence of mulberry (Morus alba L.) seedling leaves under drought stress were studied using an artificial climate chamber. The results showed that under non-drought conditions, the stomatal concentrations (Gs) and transpiratration rate (Tr) of mulberry seedling leaves decreased slightly with increased CO2 concentrations, but the net photosynthetic rate (Pn) increased significantly. Under mild drought stress (5 days of drought), higher CO2 concentrations significantly affected the photosynthetic gas exchange of mulberry seedling leaves, but had little effect on chlorophyll fluorescence. Under severe drought stress (10 das of drought), increased CO2 concentrations not only alleviated drought stress by increasing the WUE of mulberry seedling leaves, but also significantly increased its PSII photochemical activity, which promoted electron transfer on the PSII acceptor side. In conclusion, increased CO2 concentrations could raise the WUE of mulberry seedling leaves under normal water conditions and drought stress, and this effect was more significant under drought stress. Under severe drought stress, increased CO2 concentrations improved the drought resistance of mulberry seedlings by improving their PSII function

Poly(A)-seq: A method for direct sequencing and analysis of the transcriptomic poly(A)-tails.

Poly(A) tails at the 3' end of eukaryotic messenger RNAs control mRNA stability and translation efficiency. Facilitated by various NGS methods, alternative polyadenylation sites determining the 3'-UTR length of gene transcripts have been extensively studied. However, poly(A) lengths demonstrating dynamic and developmental regulation remain largely unexplored. The recently developed NGS-based methods for genome-wide poly(A) profiling have promoted the study of genom-wide poly(A) dynamics. Here we present a straight forward NGS-method for poly(A) profiling, which applies a direct 3'-end adaptor ligation and the template switching for 5'-end adaptor ligation for cDNA library construction. Poly(A) lengths are directly calculated from base call data using a self-developed pipeline pA-finder. The libraries were directly sequenced from the 3'-UTR regions into the followed poly(A) tails, firstly on NextSeq 500 to produce single-end 300-nt reads, demonstrating the method feasibility and that optimization of the fragmented RNA size for cDNA library construction could detecting longer poly (A) tails. We next applied Poly(A)-seq cDNA libraries containing 40-nt and 120-nt poly(A) tail spike-in RNAs on HiSeq X-ten and NovaSeq 6000 to obtain 150-nt and 250-nt pair-end reads. The sequencing profiles of the spike-in RNAs demonstrated both high accuracy and high quality score in reading poly(A) tails. The poly(A) signal bleeding into the 3' adaptor sequence and a sharp decreased quality score at the junction were observed, allowing the modification of pA-finder to remove homopolymeric signal bleeding. We hope that wide applications of Poly(A)-seq help facilitate the study of the development- and disease-related poly(A) dynamics and regulation, and of the recent emerging mixed tailing regulation

Experimental and Theoretical Studies on Rhodium-Catalyzed Coupling of Benzamides with 2,2-Difluorovinyl Tosylate: Diverse Synthesis of Fluorinated Heterocycles

Fluorinated heterocycles play an important role in pharmaceutical and agrochemical industries. Herein, we report on the synthesis of four types of fluorinated heterocycles via rhodium­(III)-catalyzed CH activation of arenes/alkenes and versatile coupling with 2,2-difluorovinyl tosylate. With <i>N</i>-OMe benzamide being a directing group (DG), the reaction delivered a monofluorinated alkene with the retention of the tosylate functionality. Subsequent one-pot acid treatment allowed the efficient synthesis of 4-fluoroisoquinolin-1­(2<i>H</i>)-ones and 5-fluoropyridin-2­(1<i>H</i>)-ones. When <i>N</i>OPiv benzamides were used, however, [4 + 2] cyclization occurred to provide <i>gem</i>-difluorinated dihydroisoquinolin-1­(2<i>H</i>)-ones. Synthetic applications have been demonstrated and the ready availability of both the arene and the coupling partner highlighted the synthetic potentials of these protocols. Mechanistically, these two processes share a common process involving NH deprotonation, CH activation, and olefin insertion to form a 7-membered rhodacycle. Thereafter, different reaction pathways featuring β-F elimination and CN bond formation are followed on the basis of density functional theory (DFT) studies. These two pathways are DG-dependent and led to the open chain and cyclization products, respectively. The mechanistic rationale was supported by detailed DFT studies. In particular, the origins of the intriguing selectivity in the competing β-F elimination versus CN bond formation were elucidated. It was found that β-F elimination is a facile event and proceeds via a <i>syn</i>-coplanar transition state with a low energy barrier. The CN bond formation proceeds via a facile migratory insertion of the RhC­(alkyl) into the Rh­(V) amido species. In both reactions, the migratory insertion of the alkene is turnover-limiting, which stays in good agreement with the experimental studies