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Dichloromethane, as a readily available and inexpensive C1 synthon is proposed as a powerful building block for cyclopropanation of alkenes under mild conditions. Herein, we report a highly efficient and versatile dual photoredox system, involving a nickel aminopyridine coordination complex and a photocatalyst, for the cyclopropanation of aromatic olefins using dichloromethane, under visible‐light irradiation. The cyclopropanation protocol has been successfully applied at gram scale. Mechanistic studies suggest a Ni(II) pyridyl radical complex as the key intermediate for the homolytic cleavage of the Csp3−Cl bond, generating a chloromethyl radical that is captured by the olefin coupling partner. Our findings also highlight the versatility of this methodology. By directing the radical/polar crossover process, we were able to selectively drive the reaction towards either the formation of cyclopropyl derivatives or the corresponding non‐cyclic alkyl chloride products. The methodology also successfully apply to geminal dichloroalkanes, including the formation of spiro[2,2] compounds. Moreover, our methodology extends to the synthesis of deuterium‐labelled cyclopropanes, demonstrating its utility in isotopic labelling and broadening its applicability in chemical synthesis and drug development. [ABSTRACT FROM AUTHOR]

Functionalized primary alkyl chlorides are precursors to a plethora of scaffolds but their access from chemical feedstocks remains challenging. Herein, we report a concise dual Ni/photoredox catalytic protocol for regioselective chlorocarbonylation of unactivated alkenes that enables rapid access to β‐keto primary chlorides. The catalytic process features an extensive substrate scope, scalability and functional group tolerance. The Ni/photocatalytic Cl⋅ generation and subsequent cross‐coupling is implicated for the process based on the control experiments and DFT study. The synthetic utility of the protocol has been further corroborated through functionalization of complex substrates and modifications of the product. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A metal‐free, green, and sustainable functionalization of unactivated alkyl sp3 C—H bonds is reported using iodine(III) as a feasible dehydrogenation agent under visible light or KBr, and alkyl chlorides, bromides, alcohols, and ketones could be constructed by addition of different coupling reagents. Cheap and safe iodobenzene diacetate was used to form a radical to activate the alkyl sp3 C—H bond in a highly efficient manner, which can construct different alkylation products by adding corresponding coupling reagents. [ABSTRACT FROM AUTHOR]

We describe here the development of a visible light driven nickel carbonylation catalyst. The combination of the large bite‐angle Xantphos ligand with nickel(0) generates a catalyst capable of activating alkyl halides toward carbonylation at ambient temperature in the presence of blue light irradiation, and the reductive elimination of high energy acid chloride products. Unlike classical carbonylations, where the coordination of carbon monoxide inhibits the reactivity of earth abundant nickel catalysts, a CO‐associated nickel is found to be the active catalyst in the reaction. Coupling the build‐up of acid chlorides with nucleophile addition can be used to access various amides, esters and thioesters, including those of sterically encumbered substrates or with metal‐reactive functionalities. [ABSTRACT FROM AUTHOR]

The inertness of chloroalkanes has precluded them as coupling partners for cross‐coupling reactions. Herein we disclose a general strategy for the activation of inert alkyl chlorides through photoredox catalysis and their use as coupling partners with alkenes. The catalytic system is formed by [Ni(OTf)(Py2Tstacn)](OTf) (1Ni), which is responsible for the Csp3−Cl bond activation, and [Ir(NMe2bpy)(ppy)2]PF6, (PCIrNMe2), which is the photoredox catalyst. Combined experimental and theoretical studies show an in situ photogenerated NiI intermediate ([Ni(Py2Tstacn)]+) which is catalytically competent for the Csp3−Cl bond cleavage via a SN2 mechanism for primary alkyl chlorides, forming carbon‐centered free radicals, which react with the olefin leading to the formation of the Csp3−Csp3 bond. These results suggest inert alkyl chlorides can be electrophiles for developing new intermolecular strategies in which low‐valent aminopyridine nickel complexes act as key catalytic species. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The asymmetric reductive arylation and alkenylation of benzylic chloride under photoredox/nickel dual catalysis using chiral biimidazoline (BiIm) ligand is reported to access 1,1‐diaryl alkanes and aryl allylic compounds with good yield as well as stereo‐ and enantioselectivities. This protocol uses more commercially available and less expensive C(sp2)‐Br as the electrophile coupling partner. A primary result using alkenyl chloride and alkyl chloride is also reported. Various functional groups are tolerated and the applications of this method are investigated by late‐stage functionalization and gram‐scale reaction. [ABSTRACT FROM AUTHOR]

A protocol for performing atom transfer radical addition of activated alkyl chlorides to alkenes is described. The reaction is promoted by blue light in the presence of an organic photocatalyst (3DPA2FBN), serving to generate free radicals, and a copper complex (IMesCuCl), which facilitates the chlorine transfer step. The reaction works efficiently with fluorinated and non‐fluorinated α‐chloroesters. [ABSTRACT FROM AUTHOR]

A photocatalytic borylation of alkyl bromides and chlorides in air under visible-light irradiation by graphene-supported Cu-Pd alloy nanoparticles is reported. [Display omitted] • An efficient photocatalytic protocol for borylation of alkyl halides is reported. • A graphene supported Cu/Pd alloy nanoparticles was employed as photocatalyst. • The borylations were conducted at 30 °C in air under visible light. • Primary and secondary alkyl bromides and chlorides were borylated in good yields. • The high activity results from LSPR of Cu and alloy surface charge heterogeneity. A highly efficient photocatalytic protocol for borylation of alkyl bromides and chlorides with graphene supported Cu/Pd alloy nanoparticles as a heterogeneous catalyst is reported. This photocatalytic system operates with visible light in air, providing a wide range of primary and secondary alkyl halides with B 2 pin 2 or B 2 neop 2 in high yields at low temperatures, thereby demonstrating its broad utility and functional group tolerance. The high performance is attributed to a synergistic effect of localized surface plasmon resonance (LSPR) of Cu and charge transfer from Cu to Pd due to the alloy surface charge heterogeneity. Transfer of energetic electrons from Pd to electrophilic alkyl halides lead to the formation of the alkyl radicals, which quickly react with a nucleophilic adduct of a diboron compound with base adsorbed on the positively charged Cu sites to form the corresponding borylation product. [ABSTRACT FROM AUTHOR]

Here, we demonstrate that a metallaphotoredox‐catalyzed cross‐electrophile coupling mechanism provides a unified method for the α‐arylation of diverse activated alkyl chlorides, including α‐chloroketones, α‐chloroesters, α‐chloroamides, α‐chlorocarboxylic acids, and benzylic chlorides. This strategy, which is effective for a wide variety of aryl bromide coupling partners, is predicated upon a halogen atom abstraction/nickel radical‐capture mechanism that is generically successful across an extensive range of carbonyl substrates. The construction and use of arylacetic acid products have further enabled two‐step protocols for the delivery of valuable building blocks for medicinal chemistry, such as aryldifluoromethyl and diarylmethane motifs. [ABSTRACT FROM AUTHOR]

Keywords: Chloroalkanes; Cross-Coupling; Photocatalysis; Reaction Mechanisms; Synthetic Methods EN Chloroalkanes Cross-Coupling Photocatalysis Reaction Mechanisms Synthetic Methods 1 1 1 05/11/22 20220516 NES 220516 B Photocatalysis b The photoredox activation of inert chloroalkanes for cross-coupling reactions with olefins is presented by Julio Lloret-Fillol et al. in their Research Article (e202114365). Chloroalkanes, Cross-Coupling, Photocatalysis, Reaction Mechanisms, Synthetic Methods Frontispiece: Photoredox Activation of Inert Alkyl Chlorides for the Reductive Cross-Coupling with Aromatic Alkenes. [Extracted from the article]