Mild, Redox‐Neutral Formylation of Aryl Chlorides through the Photocatalytic Generation of Chlorine Radicals

Abstract

We report a redox-neutral formylation of aryl chlorides that proceeds through selective 2-functionalization of 1,3-dioxolane via nickel and photoredox catalysis. This scalable, benchtop approach provides a distinct advantage over traditional reductive carbonylation in that no carbon monoxide, pressurized gas, or stoichiometric reductant is employed. Mild conditions enable unprecedented scope from abundant and complex aryl chloride starting materials.

Alkyl Carbon–Carbon Bond Formation by Nickel/Photoredox Cross‐Coupling

“…Dioxolane 57 is also amenable to HAT/cross-coupling,which provides am ild and redox-neutral method to access masked aldehydes (Table 2, entry 3). [61] An alternative approach to accomplish HAT-initiated dual catalytic cross-coupling is the use of an amine reagent to conduct targeted H-atom abstraction ( Figure 4B). Thus, quinuclidine derivatives were used to accomplish C À H arylation of pyrrolidine derivatives (Table 2, entry 5).…”

Asymmetric Synthesis of 1,4‐Dicarbonyl Compounds from Aldehydes by Hydrogen Atom Transfer Photocatalysis and Chiral Lewis Acid Catalysis

“…Secondary alkyl aldehydes, either acyclic ( 13 ) or cyclic ( 14 , 15 ), were viable coupling partners. Compound 16 , a masked aldehyde, was synthesized in good yield (73 %) with excellent enantioselectivity (98 %) by using readily available 1,3‐dioxolane as the solvent . Aryl aldehydes were less reactive than aliphatic aldehydes and the reactions had to be conducted at 30 °C to achieve synthetically useful conversions ( 17 – 21 ).…”

Activation and Deactivation Strategies Promoted by Medium Effects for Selective Aliphatic C−H Bond Functionalization

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Ther eagents that are typically involved in these processes include heteroatomcentered radicals and radical ions,p hotoexcited species and photocatalysts (carbonyl compounds,polyoxometalates), biocatalysts (cytochrome P450 and oxygenases) and bioinspired catalysts,a swell as closed-shell species such as dioxiranes. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Ther eagents that are typically involved in these processes include heteroatomcentered radicals and radical ions,p hotoexcited species and photocatalysts (carbonyl compounds,polyoxometalates), biocatalysts (cytochrome P450 and oxygenases) and bioinspired catalysts,a swell as closed-shell species such as dioxiranes.…”

“…Among the available methods for the site-selective functionalization of aliphatic CÀHb onds,t hose based on hydrogen atom transfer (HAT) to radical or radical-like species play an important role. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Ther eagents that are typically involved in these processes include heteroatomcentered radicals and radical ions,p hotoexcited species and photocatalysts (carbonyl compounds,polyoxometalates), biocatalysts (cytochrome P450 and oxygenases) and bioinspired catalysts,a swell as closed-shell species such as dioxiranes.…”