Introduction to Radical Addition

Herein, we report an intermolecular, enantioselective three-component radical vicinal dicarbofunctionalization reaction of olefins enabled by merger of radical addition and cross-coupling using photoredox and copper dual catalysis.

The sequence relies on the radical addition of SF5Cl to the alkynyl p-system of 2-ethynyl anilines followed by a cyclization reaction.

Furthermore, the divinyl compound was transformed into a HODAM-bearing diol via the radical addition of 2-mercaptoethanol to the vinyl groups.

The results show that, in water, scavenging activity mainly occurs through a radical addition mechanism for both isomers, while, in the lipid-like environment, the radical addition process is favored for iso-moracin C, while, redox- and non-redox-type reactions can equally occur for moracin C.

A protocol for stereoselective C-radical addition to a chiral glyoxylate-derived N-sulfinyl imine was developed through visible light-promoted photoredox catalysis, providing a convenient method for the synthesis of unnatural α-amino acids.

The nitroso radical was generated from tert-butyl nitrite and triggered the radical addition/cyclization/iodination/oxidation sequences.

This transformation demonstrated a broad substrate scope and presented excellent regioselectivity after radical addition and subsequent deprotonation to form the derivatized 1,5-dihydro-2H-pyrrol-2-one scaffold in one pot.

Characterization by Fourier transform infrared (FTIR) spectra and differential scanning calorimetry (DSC) indicated that the AOHBP could be grafted onto the macromolecules of XLPE through radical addition reaction on the vinyl during peroxide cross-linking process.

Two possible pathways have been investigated: (a) imine reduction followed by radical–radical coupling and (b) radical addition followed by product reduction.

Block-copolymers were synthesized by radical addition–fragmentation chain-transfer (RAFT) polymerization using dithiobenzoate or trithiocarbonate chain-transfer agent depending on the first monomer, further forming the hydrophilic block.

With the goal of accessing yet unknown SF5-cyclopropyl building blocks, the radical addition of SF5Cl to cyclopropenes was investigated.

Syntheses of stereochemically pure and selectively protected diamino diacids can be achieved by redox decarboxylation of distal N-hydroxyphthalimide esters of protected aspartic, glutamic or α-aminoadipic acids via radical addition to methylideneoxazolidinones.

The reaction undergoes sequential decarbonylation and radical addition using aliphatic aldehyde as a cheap and abundant alkyl radical source.

This work explores the termination reactions that lead to decreased control over polymer molecular weight and identifies a reaction leading to radical addition to the phenazine core.

Under visible light irradiation, the resultant alkoxyalkyl radical directly engages in radical cross-coupling with α-amino radical from amino C-H bonds or radical addition with alkene or phenylacetylene, respectively.

In addition, general remarks about the most important aspects of the chemical reactivity, including hydrogenation, halogenation, oxidation, reduction, cycloaddition reactions, and nucleophilic, electrophilic, and radical additions are presented.

Specifically, we review (i) the spectroscopy of sulfur-containing astrochemical molecules in the condensed phase, (ii) atom and radical addition reactions, (iii) the thermal processing of sulfur-bearing ices, (iv) photochemical experiments, (v) the non-reactive charged particle radiolysis of sulfur-bearing ices, and (vi) sulfur ion bombardment of and implantation in ice analogues.

A series of bifunctional phosphine compounds promising as γ-functionalized phosphine ligand precursors are conveniently synthesized by the radical addition of diphenylphosphine oxide (Ph2P(O)H) to allylic compounds under photoirradiation.

Herein, recent advances of these compounds were summarized as five pathways according to their mechanisms: (1) radical addition and cyclization; (2) cyclization and ring-opening; (3) radical addition and coupling; (4) radical addition and elimination; (5) coupling with nucleophilic partners (C-H, N-H, O-H and S-H).

A modular, stereoselective route to trisubstituted (Z)-alkenyl (MIDA)boronates is described, consisting of the radical addition-fragmentation of dithiocarbonates to 2-(MIDA)boronyl-3-(2'-fluoro-pyridyl-6'-oxy)-alkenes.

The increase in the number of methyl substituents in the heterocyclic group of SMZ and the corresponding increase in the steric hindrance of radical addition, reduced mineralization rates below those of SMR and SDZ.

Radical addition to chiral N-acylhydrazones has generated unusual amino acids tubuphenylalanine (Tup) and tubuvaline (Tuv) that are structural components of the tubulysin family of picomolar antimitotic agents and previously led to a tubulysin tetrapeptide analog with a C-terminal alcohol.

Mechanisms like radical addition, C–H activation, elimination, metal-catalyzed coupling, cyclization, oxidation, and rearrangement will be analyzed herein.

In cold diffuse environments, such as the interstellar medium, rates of radical addition may be enhanced when the σ-type radical is charged.

6 Fe or Fe triflate salts have performed better than other Fe salts in oxidation, radical addition, and C–O bond silylation.

From the view of mechanistic point, the radical addition reaction exclusively occurred at the electron-rich aromatic region beyond electron-deficient N-heterocycle ring.

In the last decade, less stable but more reactive electron-deficient N-oxyl radicals have been harnessed as reagents for oxidative functionalization of organic substrates via selective C-H bond cleavage or radical addition to C = C bonds.

This protocol is supposed to occur via a radical/ionic relay process, including a TBADT-mediated HAT to cleave the inert C(sp3)-H bond, a 1,4-radical addition, a back hydrogen abstraction, and an enantioselective protonation.

C-radicals readily generated through radical addition onto alkenyl aryl boronate complexes are shown to engage in 1,5-aryl migration reactions to provide 4-aryl-alkylboronic esters.

Experimental and theoretical studies elucidated that the reaction proceeds through a radical addition pathway in which the benzopyrylium cation intermediate acts as both an electrophile and a photo-redox catalyst.

It is well documented that SO4 •- can produce similar oxygen-containing transformation products as hydroxyl radical-based treatment processes, but SO4 •- also has the potential to produce organosulfates by radical addition.

This reactivity provides a mechanistically alternative tactic for sp2 carbon-boron bond assembly where the elementary steps of transition-metal mediated C-H activation and reductive elimination from azine-organometallic intermediates are replaced with a direct, Minisci9-style, radical addition.

We report herein a mild electro-oxidative method for efficient C–H alkylation of quinoxalin-2(1H)-ones by means of radical addition reactions of alkyl boronic acids and esters and alkyl trifluoroborates to afford C–C coupled products.

The overall catalytic cycles include the following basic steps: the oxidative addition, reduction, radical production, radical addition, reductive elimination and the catalyst regeneration.

Polymerization of allyl ether monomers has previously been considered a free-radical addition polymerization mechanism, but it is difficult to achieve because of the high electron density of their double bond.

When gold catalysis meets photocatalysis, a valence change of the gold center can easily be achieved via electron transfer and radical addition, avoiding the use of stoichiometric sacrificial external oxidants.

Through a relay olefination and radical addition process, we were able to develop the cascade Wittig/hydroalkylation reactions induced by visible light.

The utility of this metal- and photocatalyst-free transformation is demonstrated through the multicomponent synthesis of complex α-fluoromethyl amines and amino acid derivatives via radical addition to in situ-formed iminium ions, and the construction of β-fluoromethyl esters and amides from electron-deficient alkene acceptors.

This uranyl salt enables the remarkable smooth functionalization of unactivated (cyclo)alkanes, ethers, acetals, and amides via radical addition onto electrophilic olefins.

The protocol may proceed through the Meyer–Schuster rearrangement of propargyl alcohols to give allenol intermediates, which is followed by the radical addition/intramolecular oxidative C–H bond cyclization sequence to afford differently substituted 2-sulfenylindenones.

Our results reveal that radical addition is the dominant pathway for both OH and.

Aliphatic aldehydes were oxidatively decarbonylated into 1°, 2° and 3° alkyl radicals conveniently, allowing for the subsequent cascade construction of C(sp3)-C(sp3) and C(sp3)-C(sp2) bonds via radical addition and HAS-type cyclization.

Classical methods for the introduction of alkyl groups to arenes are mostly based on the Friedel-Crafts reaction, radical additions, metalation, or prefunctionalization of the arene: these methods, however, suffer from limitations in scope, efficiency, and selectivity.