Photocatalytic Bicyclization of Indole-Tethered 1,6-Enynes for Diastereoselective Synthesis of Pyrrolo[3,2,1-jk]carbazoles

A visible-light-driven photocatalytic protocol is established for the diastereoselective synthesis of pyrrolo[3,2,1-jk]carbazoles via a radical-triggered multicomponent bicyclization reaction starting from readily available indole-tethered 1,6-enynes and α-benzyl-α-bromomalonates under mild conditions. This photocatalytic approach exhibits a wide substrate compatibility and excellent tolerability toward various functional groups and boasts the benefit of efficient ring formation and chemical bond creation.

Olefin skeletal rearrangement enabling access to multiarylated N-sulfonyl amidines

A base-promoted olefin skeletal rearrangement strategy from para-quinone methides (p-QMs) and N-fluoroarenesulfonamides is reported, enabling direct nitrogen insertion of olefins to produce a series of multiarylated (Z)-N-sulfonyl amidines with complete stereoselectivity and generally good yields. Using p-QMs without o-hydroxy substituents gave triarylated N-sulfonyl amidines, whereas tetraarylated N,N'-disulfonyl amidines were synthesized with the existence of o-hydroxy groups.

Copper(II)/DBU Relay Catalyzed Annulation of α-Carbonyl-γ-alkynyl Sulfoxonium Ylides for Accessing N-Sulfonamido 2H-Isoindoles

A copper(II)/DBU relay catalyzed annulation of α-carbonyl-γ-alkynyl sulfoxonium ylides as a new class of sulfoxonium ylide reagents with sulfonyl hydrazides is reported, enabling intramolecular oxygen migration to produce a series of N-sulfonamido 2H-isoindoles with good yields. The present annulation proceeded readily by combining the Cu(II)-catalyzed 6-endo-dig oxo-cyclization with the DBU-catalyzed isochromene skeletal rearrangement, resulting in the formation of multiple new chemical bonds.

PhI(OAc)2-mediated aminoacyloxylation of β,γ-unsaturated hydrazones using Togni reagent II as an acyloxyl precursor

A metal-free protocol for the direct construction of C(sp2)-N and C-O bonds via a PhI(OAc)2-mediated dehydrogenative aminoacyloxylation of β,γ-unsaturated hydrazones with Togni reagent II is reported. Initiated by the carboxyl-containing species generated in situ from Togni reagent II, this method offers a new solution for regioselective functionalization at a remote site on β,γ-unsaturated hydrazones, thus providing a straightforward method for the synthesis of acyloxyl-substituted pyridazines. This reaction features a broad substrate scope and mild conditions.

Pd-Catalyzed Asymmetric Annulative Dearomatization of Phenols for Regio- and Enantioselective Synthesis of Spirocyclohexadienones

A palladium-catalyzed asymmetric annulative dearomatization of phenols with butene dicarbonate is reported, enabling twofold decarboxylative allylation to regioselectively produce a range of spirocyclohexadienones with 29-95% yields and 74-99% ee. A catalytic dearomative formal [4 + 2] cyclization of 1,1'-biphenyl-2,4'-diols delivered spiro[chromane-4,1'-cyclohexane]-2',5'-dien-4'-ones with high enantioselectivity, whereas enantioenriched spiro[cyclohexane-1,4'-quinoline]-2,5-dien-4-ones were generated starting from 2'-amino-[1,1'-biphenyl]-4-ols as 1,4-dinucleophiles.

Annulative Aminosulfonylation of Unactivated Alkenes for Accessing Pyrazolines via Multicomponent SO2 Insertion

A direct arylsulfonylation of β,γ-unsaturated hydrazones method, in which sulfonated pyrazolines are accessed by a three-component reaction of β,γ-unsaturated hydrazones, DABSO, and aryldiazonium tetrafluoroborates, has been developed without external oxidants or catalysts. This transformation is triggered by the formation of arylsulfonyl radicals in situ from the reaction of aryldiazonium tetrafluoroborates and DABSO, and is enabled by controllable generation of C center radical, in which DABSO was utilized as the sulfone source and an oxidant in this radical-mediated cascaded reaction. A wide range of substrates can be applied in this process to afford pyrazolines in good yield, and it is amenable for gram-scale synthesis.

Azofuran activation for annulative rearrangement enabled by gold(I)/Brønsted acid relay catalysis

A novel gold(I)/Brønsted acid relay catalysis enabling azofuran activation to induce annulative rearrangement from 3-yne-1,2-diols and aryldiazonium tetrafluoroborates is reported, producing a series of furan-2-yl-substituted pyrrol-2-ones bearing a quaternary carbon center with good yields. Exchanging aryldiazonium tetrafluoroborate for azofuran led to skeletally identical but substituent-diverse furan-2-yl-containing pyrrol-2-ones with good yields, supporting the key azofuran activation and annulative rearrangement by gold/Brønsted acid relay catalysis.

Lewis Acid-Catalyzed Remote Site-Selective Ring Deconstruction of Cyclobuteno[a]naphthalene-4-ones to Access Unsymmetric 1,1-Diarylated Olefins

A catalytic site-selective ring deconstruction of cyclobuteno[a]naphthalene-4-ones with alcohols is reported, enabling the direct production of a wide range of unsymmetric 1,1-diarylated olefins with good yields and complete regioselectivity. The late-stage application of these resulting terminal olefins demonstrates great possibilities to apply this strategy to complex molecules. The protocol features good functional group compatibility, broad substrate scope, and controllable site selectivity.

Gold self-relay catalysis enabling annulative oxygenation of propargylic alcohols with O-nucleophiles

A new gold(I) self-relay catalysis reaction enabling the annulative oxygenation of propargylic alcohols with various O-nucleophiles, such as carboxylic acids, alcohols and TBHP, is reported, producing a series of functionalized benzofurans in moderate to good yields under mild conditions. This protocol benefits from the π- and σ-Lewis acid capability of gold complexes, demonstrating high molecular convergence, broad substrate flexibility, high functional group compatibility and mild conditions.

Exploiting the reactivities of ortho-alkynyl aryl ketones: Opportunities in designing catalytic annulation reactions

ortho-Alkynyl aryl ketones as highly reactive and versatile synthons have been broadly applied in organic synthesis in the past decade considering their high reactivity and structural diversity. Among numerous transformations...

Azoarene activation for Schmidt-type reaction and mechanistic insights

The Schmidt rearrangement, a reaction that enables C-C or C-H σ bond cleavage and nitrogen insertion across an aldehyde or ketone substrate, is one of the most important and widely used synthetic tools for the installation of amides and nitriles. However, such a reaction frequently requires volatile, potentially explosive, and highly toxic azide reagents as the nitrogen donor, thus limiting its application to some extent. Here, we show a Schmidt-type reaction where aryldiazonium salts act as the nitrogen precursor and in-situ-generated cyclopenta-1,4-dien-1-yl acetates serve as pronucleophiles from gold-catalyzed Nazarov cyclization of 1,3-enyne acetates. Noteworthy is that cycloketone-derived 1,3-enyne acetates enabled ring-expansion relay to access a series of 2-pyridone-containing fused heterocycles, in which nonsymmetric cycloketone-derived counterparts demonstrated high regioselectivity. Aside from investigating the scope of this Schmidt-type reaction, mechanistic details of this transformation are provided by performing systematic theoretical calculations.

Regio- and Enantioselective Synthesis of Dihydropyrido[1,2-a]indoles via Catalytic Asymmetric Annulative Allylic Alkylation

A palladium-catalyzed asymmetric annulative allylic alkylation reaction of 2-[(1H-indol-2-yl)methyl]malonates with (E)-but-2-ene-1,4-diyl dicarbonates is described, leading to the regio- and enantioselective synthesis of dihydropyrido[1,2-a]indoles with a chiral cyclic allyl stereocenter adjacent to the ring-junction nitrogen atom in moderate to good yields. The salient features of this protocol include mild conditions, a broad substrate scope, and good compatibility with substituents as well as high regio- and stereoselectivities, providing a catalytic asymmetric entry for fabricating chiral pyridoindole scaffolds.

Catalytic Benzannulation Reactions of Enynones for Accessing Heterocycle-Incorporating Diarylmethanes

Two catalytic benzannulation/1,4-addition cascades of available enynones with indoles or tetronic acid-derived enamino lactones as C-nucleophiles are reported, producing 53 examples of heterocycle-incorporating diarylmethanes with moderate to excellent yields. The combination of AgOTf and Sc(OTf)3 permits bimetallic synergistic catalysis of the reaction of enynones with indoles to access 35 triarylmethanes in generally good yields with ortho-naphthoquinone methides, generated in situ, as the key intermediates. Exchanging indoles for tetronic acid-derived enamino lactones resulted in 18 diarylmethanes by the Ag-catalyzed benzannulation/1,4-addition cascade. Both reactions are advantageous for their high atom utilization and mild reaction conditions, providing intriguing complementary approaches for the direct syntheses of new heterocycle-containing diarylmethanes.

Regulatory role of KCa3.1 in immune cell function and its emerging association with rheumatoid arthritis

Rheumatoid arthritis (RA) is a common autoimmune disease characterized by chronic inflammation. Immune dysfunction is an essential mechanism in the pathogenesis of RA and directly linked to synovial inflammation and cartilage/bone destruction. Intermediate conductance Ca²⁺-activated K⁺ channel (KCa3.1) is considered a significant regulator of proliferation, differentiation, and migration of immune cells by mediating Ca²⁺ signal transduction. Earlier studies have demonstrated abnormal activation of KCa3.1 in the peripheral blood and articular synovium of RA patients. Moreover, knockout of KCa3.1 reduced the severity of synovial inflammation and cartilage damage to a significant extent in a mouse collagen antibody-induced arthritis (CAIA) model. Accumulating evidence implicates KCa3.1 as a potential therapeutic target for RA. Here, we provide an overview of the KCa3.1 channel and its pharmacological properties, discuss the significance of KCa3.1 in immune cells and feasibility as a drug target for modulating the immune balance, and highlight its emerging role in pathological progression of RA.

Electrochemical selective annulative amino-ketalization and amino-oxygenation of 1,6-enynes

A new electrochemical selective annulative amino-ketalization and amino-oxygenation of 1,6-enynes with disulfonimides and alcohols is reported, producing a series of functionalized benzofurans under catalyst- and oxidant-free conditions. The annulative aminoketalization proceeds with simple short-chain alcohols such as methanol, ethanol and n-propanol as O-nucleophilic reagents, while the reaction occurs in the annulative aminooxygenation direction in the presence of water and large steric sec-butyl alcohol (SBA).

Nitrative bicyclization of 1,7-diynes for accessing skeletally diverse tricyclic pyrroles

A novel metal-free nitrative bicyclization of 1,7-diynes with ^tBuONO in the presence of H₂O is reported, producing three types of skeletally diverse tricyclic pyrroles, namely pyrrolo[3,4-c]quinolines, chromeno[3,4-c]pyrroles and benzo[e]isoindoles, with moderate to good yields by simply tuning the linkers of the 1,7-diynes. This domino protocol demonstrates remarkable compatibility regarding 1,7-diynes with different linkers, such as nitrogen and oxygen atoms and a hydroxymethyl group, and ^tBuONO plays dual roles as a nitro precursor as well as a nitrogen atom source.

[Clinical analysis of 34 cases of acute fatty liver of pregnancy]

Objective: To analyze the characteristics, diagnosis and prognosis of acute fatty liver of pregnancy (AFLP), and to guide the management of AFLP patients. Methods: The clinical data of 34 AFLP patients admitted to Beijing Obstetrics and Gynecology Hospital, Capital Medical University from January 2009 to December 2019 were retrospectively analyzed. The general situation, diagnostic characteristics, treatment and maternal and neonatal prognosis of the AFLP patients were collected and analyzed. Results: The incidence of AFLP in our hospital was 0.022% (34/152 383). The age of onset was (30.6±4.9) years old, and the gestational age was (35.3±2.4) weeks. Most of the first symptom was gastrointestinal symptoms of unknown cause in the third trimester of pregnancy (53%, 18/34), accompanied by different degrees of elevated liver enzymes. Cesarean section was performed in 97% (33/34) of patients for termination of pregnancy. Only one pregnant woman was diagnosed prenatal and delivered vaginally, and the prognosis of both mother and infant was good. Five cases were transferred to intensive care unit, including 2 cases of acute renal failure, 1 case of gastrointestinal bleeding and 2 cases of disseminated intravascular coagulation. There was no maternal death. Severe asphyxia occurred in 2 neonates. Conclusions: Attention should be paid to the digestive tract symptoms during the third trimester of pregnancy and the diversity of clinical manifestations of AFLP for early detection. Once AFLP is diagnosed, pregnancy should be terminated as soon as possible to improve maternal and infant outcomes.

Diastereoselective Generation of C2-Azlactonized 2H-Chromenes via Brønsted Acid-Catalyzed Oxo-Cyclization of Propargyl Alcohols

A new Brønsted acid-catalyzed oxo-cyclization of propargyl alcohols with azlactones to synthesize C₂-azlactonized 2H-chromenes has been established that uses 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BiNPO₄H) as the catalyst and gives excellent diastereoselectivities (≥19:1 dr) in most cases. This protocol has a high compatibility with various substituents of substrates, offering a catalytic and useful entry to the fabrication of the synthetically important C₂-functionalized 2H-chromene scaffold.

Gold self-relay catalysis for accessing functionalized cyclopentenones bearing an all-carbon quaternary stereocenter

A new gold(i) self-relay catalysis consisting of a 3,3-rearrangement, Nazarov cyclization and Michael addition cascade of 1,3-enyne acetates with aurones and their derived azadienes is reported, producing functionalized cyclopentenones.

Tunable Electrocatalytic Annulations of o-Arylalkynylanilines: Green and Switchable Syntheses of Skeletally Diverse Indoles

Tunable electrocatalytic annulation reactions of o-arylalkynylanilines have been established, leading to green and divergent syntheses of skeletally diverse indoles by adjusting the electrolytes and the solvents. The presence of ammonium halides as the electrolytes enabled the halogenation of o-arylalkynylanilines to give C3-halogenated indoles whereas naphtho[1',2':4,5]furo[3,2-b]indoles could be obtained by changing the electrolyte from ammonium halides to KI. Interestingly, by combining acetone as the solvent and both NH₄I and NH₄Cl as the electrolytes, the reaction worked through an intramolecular annulation and [5 + 1] cyclization cascade to form naphtho[1',2':5,6][1,3]oxazino[3,4-a]indoles.

Cyclic Oxime Esters as Deconstructive Bifunctional Reagents for Cyanoalkyl Esterification of 1,6-Enynes

A concise copper catalysis strategy for the addition-cyclization of cyclic oxime esters across 1,6-enynes with high stereoselectivity to generate 1-indanones bearing an all-carbon quaternary center is reported. In this process, single-electron reduction of cyclic oxime esters enables deconstructive carbon-carbon cleavage to provide a key cyanopropyl radical poised for the addition-cyclization. This reaction is redox-neutral, exhibits good functional group compatibility, and features 100% atomic utilization. This process driven by copper catalyst makes readily available cyclic oxime esters as bifunctional reagents to demonstrate convergent synthesis.

Photocatalytic Biheterocyclization of 1,7-Diynes for Accessing Skeletally Diverse Tricyclic 2-Pyranones

A new and green route to skeletally diverse oxo-heterocyclic architectures such as pyrano[3,4-c]chromen-2-ones and pyrano[3,4-c]quinolin-2-ones is reported via an unprecedented photocatalytic Kharasch-type cyclization/1,5-(S_N″)-substitution/elimination/6π-electrocyclization/double nucleophilic substitution cascade starting from easily available heteroatom-linked 1,7-diynes and low-cost CBrCl₃. During this reaction process, the full scission of carbon-halogen bonds of BrCCl₃ was realized to directly build two new rings, including a lactone scaffold, using H₂O as the oxygen source of the ester group.

Copper/silver co-mediated three-component bicyclization for accessing indeno[1,2-c]azepine-3,6-diones

A new copper/silver-co-mediated three-component bicyclization of benzene-linked 1,6-enynes with ICF2CO2Et with TMSN3 was reported, and used to produce a wide range of hitherto unreported difluorinated tetrahydroindeno[1,2-c]azepine-3,6-diones with moderate to good yields. The mechanistic pathway consists of radical-induced 1,6-addition-cyclization, oxidative addition, reductive elimination, nitrene insertion and N-O cleavage, resulting in continuous multiple bond-forming events including C-C and C-N bonds to build up a 6/5/7 tricyclic framework.

Engaging yne-allenones in tunable catalytic silane-mediated conjugate transfer reductions

New tunable catalytic [2+2] cycloaddition/silane-mediated conjugate transfer reductions of yne-allenones have been developed, by which substituent-diverse cyclobutarenes with generally good yields were selectively synthesized by adjusting Fe-H and Cu-H catalytic systems. Use of the Fe-H system triggers 1,6-conjugate reduction to dihydrocyclobuta[a]naphthalen-4-ols whereas the Cu-H complex enables 1,4-conjugate reduction to cyclobuta[a]naphthalen-4(2H)-ones.

Enantio- and Regioselective CuH-Catalyzed Conjugate Reduction of Yne-Allenones

A new asymmetric catalytic conjugate reduction of yne-allenones to synthesize enantioenriched cyclobuta[a]naphthalen-4(2H)-ones has been established that uses copper-bisphosphine complexes as catalysts and gives excellent regio- and enantioselectivities (≥99% ee) in most cases. This protocol tolerates a broad scope of substrates, exhibits high compatibility with various substituents, and gives excellent stereoselectivity, providing a catalytic and efficient entry to fabrication of synthetically important chiral 6-6-4 tricarbocyclic scaffolds.

Diastereoselective Synthesis of 1,2-Dihydrobenzofuro[3,2-b]pyridines via a Carbon-Carbon Double-Bond Cleavage/Rearrangement Cascade

A new Lewis acid-catalyzed [2 + 2] cycloaddition/retroelectrocyclization (CA-RE)/1,6-addition relay of aurone-derived 1-azadienes and 1-alkynylnaphthalen-2-ols has been reported, leading to the regio- and diastereoselective synthesis of 1,2-dihydrobenzofuro[3,2-b]pyridine with a chiral carbon center and an axial chirality in good yields. This protocol enables the C-C double-bond scission/recombination to rapidly construct aza-heterocyclic architectures and features 100% atom utilization, a wide substrate scope, good compatibility with substituents, and excellent diastereoselectivity.

Engaging 1,7-diynes in a photocatalytic Kharasch-type addition/1,5-(SN'')-substitution cascade toward β-gem-dihalovinyl carbonyls

A new and general photocatalytic Kharasch-type addition/1,5-(SN'')-substitution cascade of 1,7-diynes with alkyl halides such as BrCCl3 and CBr4 was reported for the first time, and used to produce 65 hitherto unreported β-gem-dihalovinyl ketones/aldehydes with moderate to excellent yields in a highly regioselective manner. This reaction tolerates a wide scope of substrates, which offers a green and efficient entry to fabricate synthetically important β-gem-dihalovinyl carbonyl scaffolds. Notably, the late-stage application of these resulting β-gem-dihalovinyl carbonyls shows high and unique reactivity profiles and demonstrates the versatility of their derivatization.

Cu-Catalyzed radical-triggered spirotricyclization of enediynes and enyne-nitriles for the synthesis of pentacyclic spiroindenes

A new copper-catalyzed radical-triggered fluoromethylation-spirotricyclization of enediyne- and enyne-nitrile-containing para-quinone methides (p-QMs) was reported for the first time, and used to produce a series of hitherto unreported pentacyclic spiroindenes.

Synthesis of C3-alkylated benzofurans via palladium-catalyzed regiocontrolled hydro-furanization of unactivated alkenes

A new chelation-controlled hydrofuranization of unactivated olefins with α-alkynyl arylols is reported for the first time, and used to produce a wide range of C₃-alkylated benzofurans with generally good yields under mild conditions.

A photoinduced arene–alkyne [3 + 2] cycloaddition cascade of 1-alkynylnaphthalen-2-ols for tunable synthesis of skeletally diverse bridged hexacycles

Photoinduced solvent-dependent cyclodimerizations of 1-alkynylnaphthalen-2-ols were developed for the first time, producing skeletally diverse bridged hexacyclic architectures with good yields and high stereoselectivities.

Photocatalytic three-component annulation enabling stereoselective generation of (Z)-thiochromene 1,1-dioxides

A new photocatalytic three-component annulation of 2-alkynylaryldiazonium tetrafluoroborates with γ-hydroxyl terminal alkynes and sodium metabisulfite is reported and used to produce a series of (Z)-thiochromene 1,1-dioxides.

Iridium(III)-Catalyzed Difluoroalkylation–Bicyclization of 1,7-Enynes toward Benzo[a]fluoren-5-ones under Visible-Light Photoredox Conditions

A new visible-light-induced Ir(III)-catalyzed difluoroalkylation–bicyclization of 1,7-enynes with ethyl 2-bromo-2,2-difluoroacetate (BrCF2CO2Et) is described, furnishing a wide range of difluoromethyl-containing benzo[a]fluoren-5-ones in good to excellent yields. The reaction is operationally simple, proceeds with high efficiency under mild conditions, and shows excellent functional group compatibility.

Palladium/N,N'-Disulfonyl Bisimidazoline-Catalyzed Enantioselective Addition of Arylboronic Acids to Cyclic N-Sulfonyl Ketimines

The combination of Pd(TFA)₂ and an N,N'-disulfonyl bisimidazoline ligand shows high catalytic activity and excellent asymmetric induction in the addition of arylboronic acids to cyclic N-sulfonyl ketimines including benzo[d]isothiazole-1,1-dioxides, benzo[e][1,2,3]oxathiazine-2,2-dioxides, and 1,2,5-thiadiazole-1,1-dioxides, by which three types of chiral quaternary carbon-containing sultams with substantial substitution diversity were synthesized with high yields and excellent enantioselectivities (up to >99% ee). The current catalysis demonstrated a remarkable tolerance to oxygen and thus provided an operationally simple approach for constructing enantioenriched cyclic quaternary stereocenters.

Metal-Catalyzed Spiroannulation-Fluoromethylfunctionaliztions of 1,5-Enynes for the Synthesis of Stereodefined (Z)-Spiroindenes

Two classes of new catalytic spiroannulation-fluormethylfunctionaliztions of para-quinone methide (p-QM)-containing 1,5-enynes have been established under redox-neutral conditions. Palladium-catalyzed spiroannulation-iododifluoromethylation with ethyl difluoroiodoacetate oriented completely stereoselective access to (Z)-spiroindenes and the latter included copper-catalyzed three-component spiroannulation-cyanotrifluoromethylation starting from Togni's reagent and trimethylsilanecarbonitrile (TMSCN). Both reaction pathways involve fluoroalkyl radical-triggered 1,6-addition/5-exo-dig annulation/metal radical cross-coupling/reductive elimination sequence, providing practical and stereoselective protocols for rapidly constructing cyclohexadienone-containing spiroindenes with generally good yields.

Synthesis of polycyclic indoles via organocatalytic bicyclization of α-alkynylnaphthalen-2-ols with nitrones

A new organocatalytic bicyclization of α-alkynylnaphthalen-2-ols with nitrones was first reported, leading to the convergent synthesis of polycyclic indoles with substantial substitution diversity in generally good yields through scission of the N-O bond of nitrones via [3,3]-sigmatropic rearrangement. This transformation showcases the use of a quinine catalyst in a complicated cascade system that has been shown to effectively construct polycyclic heterocycles via alkyne difunctionalization.

Stereoselective synthesis of fully substituted ethylenes via an Ag-catalyzed 1,6-nucleophilic addition/annulation cascade

A catalytic 1,6-nucleophilic addition/annulation cascade was developed for the first time, and used to produce 27 hitherto unreported ethylene-linked 1-naphthol-imidazole pairs with generally good yields and complete stereoselectivity. An Ag₂O-catalyzed reaction of yne-allenone esters with tosylmethyl isocyanide proceeded efficiently, and provided a simple and convergent protocol for the synthesis of fully substituted (Z)-ethylenes whereas tetrasubstituted (E)-ethylenes were obtained when ethyl isocyanoacetate was employed in this transformation. The reaction pathway consists of [2+2] cycloaddition, 1,6-nucleophilic addition and [3+2] cycloaddition, leading to continuous multiple bond-forming events including C-C and C-N bonds to construct complex molecules.

Copper-Catalyzed Annulation-Cyanotrifluoromethylation of 1,6-Enynes Toward 1-Indanones via a Radical Process

A new Cu(II)-catalyzed annulation-cyanotrifluoromethylation of 1,6-enynes with Togni's reagent and trimethylsilyl cyanide (TMSCN) has been established, enabling the direct construction of trifluoromethylated 1-indanones with an all-carbon quaternary center in good yields. This reaction was performed by using low-cost Cu(OTf)₂ as the catalyst and Togni's reagent as both the radical initiator and a CF₃ source, providing an efficient protocol for building up an 1-indanone framework with wide functional group compatibility. The reaction mechanism was proposed through a radical triggered addition/5-exo-dig cyclization/oxidation/nucleophilic cascade.