Access to Alkyl-Substituted Lactone via Photoredox-Catalyzed Alkylation/Lactonization of Unsaturated Carboxylic Acids

An efficient photoredox-catalyzed alkylation/lactonization reaction of unsaturated carboxylic acids by using alkyl <i>N</i>-hydroxyphthalimide esters as alkylation reagents has been developed. Varieties of redox-active esters derived from aliphatic carboxylic acids were proved viable in this method, affording alkyl substituted lactones in moderate to good yields. This redox-neutral procedure features mild conditions and operational simplicity, which provides a new strategy for the synthesis of alkyl substituted lactones

Reinforcement learning based two‐timescale energy management for energy hub

Abstract Maintaining energy balance and economical operation is significant for energy hub (EH) which serves as the central component. Implementing real‐time regulation for heating and cooling equipment within the EH is challenging due to their slow response time in response to the stochastic fluctuation in renewable energy sources and demands while the opposite is true for electric energy storage equipment (EST), a conventional single timescale energy management strategy is no longer sufficient to take into account the operating characteristics of all equipment. With this motivation, this study proposes a deep reinforcement learning based two‐timescale energy management strategy for EH, which controls heating & cooling equipment on a long timescale of 1 h, and EST on a short timescale of 15 min. The actions of the EST are modelled as discrete to reduce the action spaces, and the discrete‐continuous hybrid action sequential TD3 model is proposed to address the problem of handling both discrete and continuous actions in long timescale policy. A joint training approach based on the centralized training framework is proposed to learn multiple levels of policies in parallel. The case studies demonstrate that the proposed strategy reduces the economic cost and carbon emissions by 1%, and 0.5% compared to the single time‐scale strategy respectively

Photoredox-Catalyzed Cascade Difluoroalkylation and Intramolecular Cyclization for Construction of Fluorinated γ‑Butyrolactones

A cascade visible-light photocatalytic difluoroalkylation and intramolecular cyclization reaction has been developed for the synthesis of difluoroalkylated oxygen heterocycles. The reaction was carried out under very mild conditions, affording fluorinated isobenzofuran-1-ones, lactone, and cyclic ethers with up to 97% chemical yields. Furthermore, several types of bromofluoroalkane precursors bearing ester, keto, amido, and phosphate groups could all work very well in this reaction, which provides an easy method for the preparation of functionalized difluoroalkylated oxygen heterocycles

Photoredox-Catalyzed Cascade Difluoroalkylation and Intramolecular Cyclization for Construction of Fluorinated γ‑Butyrolactones

A cascade visible-light photocatalytic difluoroalkylation and intramolecular cyclization reaction has been developed for the synthesis of difluoroalkylated oxygen heterocycles. The reaction was carried out under very mild conditions, affording fluorinated isobenzofuran-1-ones, lactone, and cyclic ethers with up to 97% chemical yields. Furthermore, several types of bromofluoroalkane precursors bearing ester, keto, amido, and phosphate groups could all work very well in this reaction, which provides an easy method for the preparation of functionalized difluoroalkylated oxygen heterocycles

Merging Photoredox and Copper Catalysis: Enantioselective Radical Cyanoalkylation of Styrenes

A photoredox and copper catalyzed asymmetric cyanoalkylation reaction of alkenes has been developed, which uses alkyl <i>N</i>-hydroxyphthalimide esters as alkylation reagents. In this radical cyanoalkylation reaction, the photoredox induced alkyl radical adds to styrene, and the generated benzylic radical couples with a chiral Box/CuII cyanide complex to achieve the enantioselective cyanation. This reaction features mild conditions, operational simplicity, broad substrate scope, high yields, and high enantioselectivities, which represents an efficient method for the asymmetric radical difunctionalization of alkenes

Detrifluoroacetylative in Situ Generation of Free 3‑Fluoroindolin-2-one-Derived Tertiary Enolates: Design, Synthesis, and Assessment of Reactivity toward Asymmetric Mannich Reactions

The discovery of detrifluoroacetylative in situ generation of a new type of fluorinated amide enolates derived from 3-fluoroindolin-2-one and their asymmetric Mannich additions with sulfinylaldimines bearing fluoroalkyl groups is reported, which afforded α-fluoro-β-(fluoroalkyl)-β-aminoindolin-2-ones containing C–F quaternary stereogenic centers with excellent yields and high diastereoselectivities

Identification of Styryl Sulfonyl Fluoride (SSF) as An Efficient, Robust and Irreversible Cysteine-specific Protein Bioconjugation Reagent

Cysteine (Cys)-specific bioconjugation has found wide application in the synthesis of protein conjugates, particularly for the functionalization of antibody. Here, through direct assessment on protein substrate, we report the discovery of trans-styryl sulfonyl fluoride (SSF) as a near perfect Michael acceptor (MA) for cysteine-specific protein bioconjugation. Com-pared to predominantly used maleimides, SSF exhibited better chemoselectivity, self-stability and conjugate-stability while kept comparable reactivity. Using SSF-derived probes, proteins can be readily modified on the Cys residue(s) to install functionalities, e.g., fluorescent dyes, toxins and oligonucleotides (oligos), without the influence of activity. Fur-ther applications of SSF derived serum stable antibody-drug conjugates and PD-L1 nanobody-oligo conjugates demon-strate the great translational value of SSF-based bioconjugation in the drug development and single-cell sequencing

<i>N</i>‑Iodosuccinimide-Promoted Cascade Trifunctionalization of Alkynoates: Access to 1,1-Diiodoalkenes

An efficient cascade trifunctioalization reaction of alkynoates with <i>N</i>-iodosuccinimide has been developed which proceeds through iodination, aryl migration, decarboxylation, and second iodination. This reaction represents an example of 1,1-difunctionalization of the acetylene bond and also provides a new strategy for the preparation of 1,1-diiodoalkenes

The Benzoyl Peroxide Promoted Dual C–C Bond Formation via Dual C–H Bond Cleavage: α‑Phenanthridinylation of Ether by Isocyanide

The benzoyl peroxide-promoted α-phenanthridinylation of ether by isocyanide is developed, proceeding through dual C–H bond cleavage and dual C–C bond formation. The procedure tolerates a series of functional groups, such as methyl, fluoro, chloro, acetyl, methoxy carbonyl, cyano, and trifluoromethyl. Thus, it represents a facile pathway leading to 6-substituted phenanthridine derivatives. The addition of radical to the isonitrile followed by a radical aromatic cyclization is involved in this transformation