Cycloaddition of nitrones with arynes generated from benzobisoxadisilole or 2,3-naphthoxadisilole

1,3-Dipolar cycloaddition of nitrones with arynes generated in situ from benzobisoxadisilole or 2,3-naphthoxadisilole afforded the oxadisilole fused benzo[d]isoxazoline or the naphtho[2,3-d]isoxazoline derivatives at room temperature in good yields.     

Synthesis of xanthones, thioxanthones, and acridones by the coupling of arynes and substituted benzoates

The reaction of silylaryl triflates, CsF, and ortho-heteroatom-substituted benzoates affords a general and efficient way to prepare biologically interesting xanthones, thioxanthones, and acridones. This chemistry presumably proceeds by a tandem intermolecular nucleophilic coupling of the benzoate with an aryne and a subsequent intramolecular electrophilic cyclization.     

Three-component coupling of arynes, aminosilanes, and aldehydes

A three-component coupling of arynes, aminosilanes, and aldehydes enables diverse amino and hydroxymethyl groups to be incorporated directly into 1,2-positions of aromatic rings.     

Palladium-catalyzed three-component coupling of arynes with allylic acetates or halides and terminal alkynes promoted by cuprous iodide

Benzynes react with allylic acetates or halides and terminal alkynes in the presence of Pd(PPh3)4, CuI and CsF in CH3CN at 50 degrees C for 5 h to give 1-allyl-2-alkynylbenzene derivatives in good to excellent yields.     

Synthesis of N-alkyl-N-hydroxyamphetamines and related nitrones

The action ofm-chloroperbenzoic acid on various amphetamines and on dibenzylamine is shown to yield N-hydroxy derivatives and related nitrones.     

Synthesis of 2H-indazoles by the [3 + 2] dipolar cycloaddition of sydnones with arynes

A rapid and efficient synthesis of 2H-indazoles has been developed using a [3 + 2] dipolar cycloaddition of sydnones and arynes. A series of 2H-indazoles have been prepared in good to excellent yields using this protocol, and subsequent Pd-catalyzed coupling reactions can be applied to the halogenated products to generate a structurally diverse library of indazoles.     

Copper-catalyzed three-component coupling of arynes, terminal alkynes and activated alkenes

The three-component coupling of benzynes with terminal alkynes and activated alkenes in the presence of CuI, PCy(3) and CsF in a 1:1 mixture of CH(3)CN and THF at 50 degrees C for 5 h gave 1-alkyl-2-alkynylbenzenes in good to moderate yields.     

三价铑催化硝酮与炔的碳氢活化偶联合成二氢吲哚

三价铑在氧化还原中性条件下催化硝酮与炔发生偶联,经过氮芳环的碳氢键活化和氧转移可以高化学选择性、中等到良好非对映选择性的得到三取代二氢吲哚。     

Synthesis of dihydrobenzisoxazoles by the [3 + 2] cycloaddition of arynes and oxaziridines

Dihydrobenzisoxazoles are readily prepared in good yields by the [3 + 2] cycloaddition of oxaziridines and arynes. The reaction involves an unusual cleavage of the C-O bond of the oxaziridine and tolerates a variety of substituents on the oxaziridine and the o-(trimethylsilyl)aryl triflate to form aryl-, heteroaryl-, alkyl-, and naphthyl-substituted dihydrobenzisoxazoles. The resulting halogen-substituted dihydrobenzisoxazoles are readily elaborated to more complex products using palladium-catalyzed crossing-coupling processes.     

Synthesis of N-arylisatins by the reaction of arynes with methyl 2-oxo-2-(arylamino)acetates

N-Arylisatins are efficiently prepared by the reaction of 2-oxo-2-(arylamino)acetates and arynes under mild reaction conditions.     

Synthesis of fused polycyclic aromatics by palladium-catalyzed annulation of arynes using 2-halobiaryls

The Pd-catalyzed annulation of arynes by 2-halobiaryls and related vinylic halides provides a very efficient, high yielding synthesis of polycyclic aromatic and heteroaromatic hydrocarbons. This process appears to involve the catalytic, stepwise coupling of two very reactive substrates, an aryne and an organopalladium species, to generate excellent yields of cross-coupled products.     

Synthesis of spiroisoxazolidinyl-benzoisothiazolines by 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes with nitrones

The spiroisoxazolidinyl-benzoisothiazoline derivatives were synthesized through a highly diastereoselective 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes with nitrones. The regiochemistry of cycloaddition was assigned on the ¹H NMR chemical shift of methane-H in 3 and 5. The relative stereochemistry of cycloadducts was determined from the single-crystal X-ray crystallography.     

Synthesis of substituted 1H-indazoles from arynes and hydrazones

The 1H-indazole skeleton can be constructed by a [3 + 2] annulation approach from arynes and hydrazones. Under different reaction conditions, both N-tosylhydrazones and N-aryl/alkylhydrazones can be used to afford a variety of indazoles. The former reaction affords 3-substituted indazoles either via in situ generated diazo compounds or through an annulation/elimination process. The latter reaction leads to 1,3-disubstituted indazoles likely through an annulation/oxidation process. The reactions operate under mild conditions and can accommodate aryl, vinyl, and less satisfactorily, alkyl groups.     

Synthesis of 3-substituted indazoles from arynes and N-tosylhydrazones

Readily available, stable, and inexpensive N-tosylhydrazones react with arynes under mild reaction conditions to afford 3-substituted indazoles in moderate to good yields. The reaction appears to involve a dipolar cycloaddition of in situ generated diazo compounds and arynes.     

Synthesis of naphthoxindoles,anthraoxindoles and phenanthrofuranones from arynes

An efficient process for the synthesis of naphthoxindoles, anthraoxindoles and phenanthrofuranones by Diels−Alder reactions and dehydrogenation aromatization reactions of benzyne or naphthyne with methyleneindolinones or methylenebenzofuranones in good yields. The photophysical, redox, and thermal properties of oxadisilole fused naphthoxindoles and anthraoxindoles have been determined. This compounds show potential applications for organic light-emitting materials due to their high fluorescence quantum yields and thermal stabilities.     

Synthesis of O-glycosylα-aryl nitrones

<正>α-Aryl nitrone are one of the most useful kinds of nitrones and have been extensively explored in recent years.However,the sugar moieties have not been introduced into these molecules before.We presented here an efficient synthesis ofα-aryl nitrone Oglycosides via condensation of N-substituted hydroxylamine and aryl aldehydes glycosides in benzene.