Generation of Phosphorus-Centered Radicals via Homolytic Substitution at Sulfur

Stereocontrolled Radical Thiophosphorylation

The first practical, fully stereoselective P(V)-radical hydrophosphorylation is presented herein by using simple, limonene-derived reagent systems. A set of reagents have been developed that upon radical initiation react smoothly with olefins and other radical acceptors to generate P-chiral products, which can be further diversified (with conventional 2e^- chemistry) to a range of underexplored bioisosteric building blocks. The reactions have a wide scope with excellent chemoselectivity, and the unexpected stereochemical outcome has been supported computationally and experimentally. Initial ADME studies are suggestive of the promising properties of this rarely explored chemical space.

Bromide ion promoted practical synthesis of phosphinothioates of sulfinic acid derivatives and H-phosphine oxides

Herein, a method for the practical synthesis of thiophosphinates under metal free and open flask conditions is reported.

Proton-Coupled Electron Transfer Enables Tandem Radical Relay for Asymmetric Copper-Catalyzed Phosphinoylcyanation of Styrenes

A tandem radical relay strategy was realized for the first Cu(I)-catalyzed enantioselective phosphinocyanation of styrenes. In this reaction, ^tBuOOSiMe₃ generated in situ from ^tBuOOH serves as a radical initiator to trigger t-butoxy radical production upon oxidization of L*Cu(I) species via proton-coupled-electron transfer (PCET) pathway, which leads to sequential phosphinoyl radical and benzyl radical formations. The resultant β-cyanodiarylphosphine oxides could be easily converted to a series of chiral γ-amino phosphine ligands.

A scalable electrochemical dehydrogenative cross-coupling of P(O)H compounds with RSH/ROH

A practical, scalable electrochemical dehydrogenative cross-coupling of P(O)H compounds with thiols, phenols and alcohols in both an undivided cell and a continuous-flow setup is disclosed. Its broad substrate scope (>50 examples), good functional-group tolerance and scalability (>10 g) show potential for practical synthesis. A preliminary mechanistic study suggests that the phosphorus radicals are involved in the catalytic cycle.

Metal- and base-free reductive coupling reaction of P(O)-H with aryl/alkyl sulfonyl chlorides: a novel protocol for the construction of P-S-C bonds

Novel and efficient synthesis of S-aryl/alkyl phosphinothioates from P(O)-H and aryl/alkyl sulfonyl chlorides under metal- and base-free conditions is described. This reaction provides an alternative strategy for the construction of P-S-C bonds in moderate to excellent yields. Moreover, this method can be readily applied to gram-scale preparation.

Rapid synthesis of carbonucleoside phophonate analogues as potential antiviral agents via a hydrophosphonylation reaction of ethynyl carbocyclic precursors

Carbonucleoside phosphonate analogues were readily obtained using a free-radical hydrophosphonylation reaction under UV/Vis light irradiation of alkyne carbocyclic precursors.

Visible light photoredox catalyzed thiophosphate synthesis using methylene blue as a promoter

A novel efficient method for the synthesis of thiophosphate derivatives catalyzed by methylene blue with blue light irradiation under an air atmosphere is described.

Metal-free electrophilic phosphination of electron-rich arenes, arenols and aromatic thiols with diarylphosphine oxides

A metal-free and mild route to aromatic organophosphorus compounds from stable phosphines.

Cs2 CO3 -Catalyzed Aerobic Oxidative Cross-Dehydrogenative Coupling of Thiols with Phosphonates and Arenes

An efficient Cs₂ CO₃ -catalyzed oxidative coupling of thiols with phosphonates and arenes that uses molecular oxygen as the oxidant is described. These reactions provide not only a novel alkali metal salt catalyzed aerobic oxidation, but also an efficient approach to thiophosphates and sulfenylarenes, which are ubiquitously found in pharmaceuticals and pesticides. The reaction proceeds under simple and mild reaction conditions, tolerates a wide range of functional groups, and is applicable to the late-stage synthesis and modification of bioactive molecules.

K2CO3-promoted aerobic oxidative cross-coupling of trialkyl phosphites with thiophenols

Phosphorylation of thiols has been achieved via K₂CO₃-promoted aerobic oxidative cross-coupling of trialkyl phosphites with thiophenols.

Probing the reactivity of H-phosphonate derivatives for the hydrophosphonylation of various alkenes and alkynes under free-radical conditions

Hydrophosphonylation of various alkenes and alkynes is reported using DPAP as a photoinitiator under UV irradiation.

Validating the alkene and alkyne hydrophosphonylation as an entry to organophosphonates

The hydrophosphonylation of terminal alkenes and alkynes by H-phosphonates affords Markovnikov and/or anti-Markovnikov adducts depending on the catalyst (a metal or a radical initiator) and the reaction conditions.

A mechanistic study on the SHi reaction at tin atoms in a radical cascade reaction

A kinetic study on the intramolecular direct radical substitution reaction on tin atoms was undertaken.

N-heterocyclic carbene catalyzed carba-, sulfa-, and phospha-Michael additions with NHC·CO₂ adducts as precatalysts

N-heterocyclic carbene catalyzed Michael additions have been revisited with 1,3-dialkyl- or 1,3-diarylimidazol(in)ium-2-carboxylates, that is, NHC·CO2 adducts, as the source of the free NHC catalysts in solution. Using these precatalysts, a number of efficient carba-, sulfa-, and phospha-Michael additions were achieved very conveniently, without the need for an external strong base to generate the NHC by deprotonation of an azolium salt. To further expand the scope of the procedure, some NHC-catalyzed sulfa-Michael/aldol organocascades were also investigated.