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A visible light-promoted radical relay of N-allylbromodifluoroacetamide with quinoxalin-2(1H)-ones was developed in which 5-exo-trig cyclization and C-C bond formation were involved. This protocol was performed under mild conditions to facilely offer a variety of hybrid molecules bearing both quinoxalin-2(1H)-one and 3,3-difluoro-γ-lactam motifs. These prepared novel skeletons would expand the accessible chemical space for structurally complex heterocycles with potential biological activities.

A visible-light-induced defluorinative dichloromethylation of α-CF

A visible-light-induced, catalyst-free radical cross-coupling cyclization of diselenides or disulfides with N-allylbromodifluoroacetamide has been developed. This developed protocol exhibits good f...

Reported herein is a visible-light-induced, catalyst-free intramolecular cyclization of 4-phenylsulfonyl-2,3,5,6-tetrachloropyridine, leading to rapid assembly of a series of unprecedented benzo[4,5]thieno[3,2

Reported herein is a photoredox-catalyzed amination of

A visible light-promoted radical relay of

A palladium-catalyzed ring-opening oxo-formal [3 + 2]-cycloaddition reaction of novel donor-acceptor spirovinylcyclopropyl oxindole with 3-oxindole is described. The developed protocol provides facile access to oxo-bispirooxindole derivatives in good yields (up to 82% yield) with excellent diastereoselectivities (up to 20:1 dr).

A visible-light-induced, catalyst-free radical cross-coupling cyclization of diselenides or disulfides with

A facile and enantioselective access to a functionalized octahydroacridine scaffold was developed via an organocatalytic domino sequence between cyclohexenone and 2- N-substituted benzaldehyde. High levels of yields (up to 99%) and enantioselectivities (up to 99:1 er) were readily achieved in this developed organocatalytic transformation, which holds promising applications in the construction of complex multicyclic systems for further pharmacological studies.

An efficient and diastereoselective decarboxylative oxa-1,3-dipolar cycloaddition between 3-oxindoles and diverse amino acids is developed to access novel oxazolidine-dispirooxindole skeletons bearing vicinal quaternary carbon centers. This protocol features operational simplicity, a broad substrate scope, and good to excellent chemical yields and diastereoselectivities. In particular, minimal solvent (1 mL/10 mmol) and chromatography-free purification render this synthetic process more efficient and environmentally benign in the context of green chemistry.

A general and straightforward protocol for di-/perfluoroalkylation of ortho-hydroxycinnamic esters via a photoredox-catalyzed cascade was developed to access a variety of 3-fluoroalkylated coumarins. This method was characterized by all-in-one synthetic design, simplified operation, mild reaction conditions, and broad substrate scope. Moreover, a sequential one-pot procedure starting from commercially available salicylaldehyde was also successfully realized to synthesize 3-fluoroalkylated coumarins.

An intramolecular [3 + 2]-annulation of amide-linked donor-acceptor cyclopropane with in situ-generated imine is described. As a result, diverse hexahydropyrrolo[3,2-c]quinolinones, as the tricyclic core of martinellines, were efficiently assembled in good to excellent yield (up to 93%) with a good diastereomeric ratio (up to 98:2).

With the aid of in situ protection by N-(2-formylphenyl)-4-methyl-benzenesulfonamide, enantioselective allylic alkylation of Morita-Baylis-Hillman carbonates with diethyl 2-aminomalonate was successfully realized. The corresponding adducts can be obtained in up to 99% yield with up to 98% ee as well as excellent regioselectivity. Besides, the adducts with opposite configurations were readily prepared by utilizing easily available and inexpensive quinine or quinidine as organocatalyst. Facile deprotection of the resulting adduct provides straightforward access to enantiopure α-methylene-γ-lactam.

A practical and straightforward synthetic route through a Selectfluor-triggered tandem cyclization of o-hydroxyarylenaminone was developed to construct a variety of difluorinated 2-amino-substituted chromanones. This novel protocol features mild reaction conditions, operational simplicity, and broad substrate scope. The enamine moiety in o-hydroxyarylenaminone played dual roles to enable high efficiency in the difluorination and intramolecular cyclization, leading to the accomplishment of a new class of difluorinated 2-amino-substituted chromanones for pharmaceutical studies.

Hydrogen-bonding organocatalysts L-pyroglutamic sulphonamides were readily synthesized for the first time by fully exploiting the potentials of L-pyroglutamic acid. The newly designed catalyst was successfully applied in catalyzing asymmetric Diels–Alder cyclization of methyleneindolinones with 2-vinyl-1H-indoles to efficiently assemble carbazolespirooxindoles in excellent stereoselectivity (up to 99% ee, >20:1 dr) and yields (up to 99%). Mechanistic studies disclosed that the well-designed hydrogen-bonding modes between L-pyroglutamic sulphonamide and substrates were crucial for stereocontrol in the cyclization.

Reductive dimerization of isatin and its derivatives can be regarded as a step-economical pathway to construct 3,3′-disubstituted bisoxindoles, which was unfortunately accompanied by severe direct reduction as well as low efficiency. A visible-light driven, photoredox-catalytic protocol was developed to readily furnish 3,3′-dihydroxy- (dl-, > 20:1 dr) and 3,3′-diamino-bisoxindoles (meso-, 3.5:1 to 5:1 dr) in moderate to good yields, successfully circumventing the common problem. Two vicinal quaternary carbon centers were effectively assembled under the irradiation of visible light.

A series of novel dispirooxindole derivatives, 3-acetyl-5-phenyl-pyrrolo(spiro-[2.3']-1'-benzyl-oxindole)-spiro-[4.3"]-1"-benzyl-oxindoles, were synthesized via 1,3-dipolar cycloaddition of the azomethine ylide with 3-acetonylideneoxindole in high regioselectivities and yields. An unusual regioselectivity was observed in this 1,3-dipolar cycloaddition, leading to the construction of novel dispirooxindole skeleton. The substituent effects on the regioselectivity were also investigated.

Highly diastereo- and enantioselective conjugate additions of azlactones to enolizable cyclic and linear enones were conducted by employing proline aryl sulfonamide as the organocatalyst in trifluorotoluene. The conjugate adducts bearing contiguous quaternary and tertiary stereocenters were obtained in moderate to good yields with excellent diastereoselectivities and moderate to good enantioselectivities. This developed protocol filled in the substrate gap for the organocatalytic conjugate addition of azlactone to enones.

A series of novel 2,3- or 2,5-dispirooxindole-piperazine ring systems were efficiently constructed through the acid-promoted self-1,3-dipolar [3+3] cyclizations of azomethine ylides derived from isatin with various primary or cyclic secondary amines. Interestingly, the regioselectivity of this self-[3+3] cyclization could be effectively tuned by varying the structural features of substrates. The unprecedented 2,5-dispirooxindole-piperazine skeleton was achieved in good diastereoselectivity by employing 1,2,3,4-tetrahydroisoquinoline, while using pyrrolidine or glycine methyl ester furnished the 2,3-dispirooxindole-piperazine scaffold in excellent diastereoselectivity (only a single isomer formed).