Photoalkylation/-arylation of ortho-Diketones with Unactivated Organic Halides

Abstract

A new method for conducting a reductive alkylation/arylation of 1,2-diketones using visible light and unactivated organic halides is presented in this article. This technique does not require a photocatalyst and employs Et 3 N, a tertiary amine, as a promoter. This amine aids in generating a ketyl radical and an α-aminoalkyl radical, which engages in a C−X bond activation via a halogen atom transfer process (XAT). This approach's success hinges on utilizing Et 3 N as the promoter. This article's mild and straightforward protocol allows for significantly expanding organic halide substrates, including primary, secondary, and aromatic organic halides and various functional groups.

Synergistic Merger of Ketone, Halogen Atom Transfer (XAT), and Nickel-Mediated C(sp3)–C(sp2) Cross-Electrophile Coupling Enabled by Light

“…On the basis of our preliminary mechanistic studies and previous literature precedents, − we propose a tentative mechanism, as shown in Scheme . Initially, in the presence of 390 nm light, the ketone is converted to either photoexcited ketone ( I ) or diradical ( I′ ) intermediate.…”

Visible-light-driven C(sp3)–H alkylation of heterobenzylic amines via electron donor–acceptor complexes

“…The high BDE values of C–Cl and C–Br bonds in the alkyl substrates were apparently responsible for their low reactivities. 26…”

Hantzsch Esters Enabled [2π+2σ] Cycloadditions of Bicyclo [1.1.0] butanes and Alkenes under Photo Conditions

“…Based on the above results, a possible reaction mechanism was proposed (Scheme ). Under the induction of visible light, the direct hydrogen atom transfer (HAT) proceeded from the C4–H of HE to ketone resulting the ketyl radical 7 (path I), ,, which is highly susceptible to ring opening and the formation of a cyclobutyl radical 8 . Afterward, complex 9 was obtained through the addition of radical 8 to alkene 2 .…”