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• DFT study on the mechanism of the Rh-catalyzed Pauson-Khand [3+2+1] cycloaddition. • Two kinds of reaction mechanisms with the reverse sequence are performed. • The calculations provide interpretation of the experimental observersed diastereoselectivity. DFT calculations have been carried out to study the mechanism of the Rh-catalyzed Pauson-Khand [3+2+1] cycloaddition reaction of vinylidene cyclopropane with carbon monoxide, as well as the diastereoselectivity of the products. It is found that reaction initializes by oxidative addition involves the distal C−C bond cleavage of cyclopropane groups, which is promoted by Rh(I) complex, to give η 4-TMM Rh(III) intermediate, followed by CO insertion. Continuing with the next process, olefin insertion, determines the formation of the cis -product or trans -product, depending on the orientation of coordinated olefin moiety to the Rh center. The calculations provide a successful interpretation of the experimental observersed diastereoselectivity. [Display omitted] [ABSTRACT FROM AUTHOR]

A transition-metal-free method to afford diverse trisubstituted allylic molecules via migratory allylation of olefins under light irradiation is described. This system tolerated diverse N-tosylhydrazones and olefinic boronic acids. Successful allylation of drugs and natural-product analogues was achieved. The gram-scale synthesis and subsequent post-transformation demonstrated the potential applications of this strategy. [ABSTRACT FROM AUTHOR]

While enantioselective hydrofluorination methods for activated alkenes represent a notable advance, the resultant enantiomeric excesses remain largely moderate, indicating the necessity for enhancements in precision, efficiency, and scope. We have recently developed an innovative nickel hydride catalytic system that enables regio- and enantioselective C–F bond formation with unactivated alkenes. By utilizing specially designed Bn-BOx ligands for improved selectivity, our approach demonstrates exceptional efficiency and selectivity with β,γ-alkenyl amide substrates. This breakthrough enhances the synthesis of organofluorine compounds, marking a significant advancement in organic synthesis. 1 Introduction 2 Reaction Design of Hydrofluorination 3 Regio- and Enantioselective Hydrofluorination 4 Asymmetric Amplification 5 Conclusions [ABSTRACT FROM AUTHOR]

Allylic ethers and alcohols are essential structural motifs commonly present in natural products and pharmaceuticals. Direct allylic C–H oxygenation of internal alkenes is one of the most direct methods, bypassing the necessity for an allylic leaving group that is needed in the traditional Tsuji–Trost reaction. Herein, we develop an efficient and practical method for synthesizing (E)-allyl ethers from readily available internal alkenes and alcohols or phenols via selective allylic C–H oxidation. Key advances include the use of a Cu/Azodiformate catalyst system to facilitate remote allylic C–H activation and the achievement of excellent chemoselectivity through a dynamic ligand exchange strategy using a bis(sulfonamide) ligand. This method features a broad substrate scope and functional group tolerance, successfully applied to the synthesis of various challenging medium-sized cyclic ethers (7-10 members) and large-ring lactones (14-20 members), with high regioselectivity and stereoselectivity. Allylic alcohols and ethers are key functional motifs widely found in various bioactive molecules, pharmaceuticals, and natural products. Here, the authors report the synthesis of (E)-allyl ethers from internal alkenes and alcohols or phenols via copper catalyzed selective allylic C–H oxidation. [ABSTRACT FROM AUTHOR]

The magnesium-mediated addition of bromoform to conjugated electron-deficient alkenes and imines, such as para -quinone methides (p -QMs) and aurone-derived azadienes, respectively, is reported here for the first time. While p -QMs undergo exclusive and hitherto unreported 1,6-addition of bromoform to afford benzylic tribromomethylated diarylmethanes, aurone-derived azadienes undergo both 1,2- and 1,4-additions to furnish α- and γ-tribromomethylamines. A mechanism involving the intermediacy of the tribromomethyl radical has been proposed based on control experiments and EPR studies. Representative synthetic transformations have also been carried out. [ABSTRACT FROM AUTHOR]

Reactions involving alkenyl acetates offer cost-effective and environmentally friendly routes for alkene synthesis, yet their asymmetric variant remains elusive. Concurrently, asymmetric conjugate alkenylation predominantly centered on nucleophilic addition using alkenyl—M. This manuscript presents an asymmetric reductive conjugate alkenylation reaction involving alkenyl acetates. The method facilitates the enantioselective addition of keto alkenyl groups to α,β-enones, resulting in the formation of unsaturated diketones—a class of useful structural motifs that are challenging to access otherwise. The use of electron-rich Pyroxy ligand is essential for achieving both high reaction efficiency and enantioselectivity. [ABSTRACT FROM AUTHOR]