Copper-mediated 1,4-conjugation reaction of functionalized alkylzinc iodides with derivatives of β-nitrostyrene

Functionalized alkylzinc iodides will undergo 1,4-conjugation reaction with derivatives of β-nitrostyrene in the presence of Cu(OAc)2/LiCl to afford a polyfunctional nitro-compound in high yield.

Regioselective aminohalogenation of β-nitrostyrenes using NCS and NBS as nitrogen/halogen sources

Aminohalogenation reaction of β-nitrostyrenes with N-halosuccinimides(N-chloro and N-bromosuccinimides) has been successfully conducted by using nickel acetate as a catalyst in the presence of potassium carbonate and succinimide as co-additives.The reaction was easily performed at room temperature under nitrogen gas protection to give dihalorinaed haloamino products in good to excellent yields(60%-98%).The structure has been confirmed by X-ray crystal structure analysis.

ONE'POT REACTION OF TRIVALENTPHOSPHORUS COMPOUNDS (Ⅰ)——A NOVEL ONE-STEP REACTION OF ADDITION,REDUCTION AND CYCLIZATION OF SUBSTITUTED β-NITROSTYRENE WITH O,O-DIALKYL PHOSPHITES

<正> In this paper the reaction of substituted β-nitrostyrene with O,O-dialkyl phosphite under cocatalysis of trimethylsilyl chloride （TMS-C1） and triethylamine （or other acidbinding agent） has been first studied and the new cyclization reaction leading to the formation of product Ⅱ, as a new class of derivatives of 1-hydroxyindoles, difficultly accessible or inaccessible with usual methods has been observed. In the related reaction it is surprising that when the Arbuzov rearrangement occurs under mild conditions, the addition, reduction and cyclization as a one-pot reaction take place simultaneously with the formation of products Ⅰ, Ⅱ, Ⅲ. By controlling the reaction conditions the products were formed almost in specificity, and thus the most interesting cyclic products Ⅱa-hcontaining phosphorus-carbon bond were obtained. Their structures were confirmed by elemental analysis, IR,1H or31p NMR and MS spectra. The crystal structure of representative compound Ⅱhwas determined by X-ray diffract

The combination of benzamides/NCS as nitrogen/halogen sources for aminohalogenation of β-nitrostyrenes resulting in dichlorinated haloamides

The combination of benzamide and NCS was found to be an efficient nitrogen/halogen source for aminohalogenation of β-nitrostyrenes.The reaction was convenient to carry out by using 4-dimethylaminopyridine as the catalyst,resulting in vicinal dichlorinated haloamino nitroalkanes with opposite regiochemistry to that generated from other electron-deficient olefins observed previously.The reaction proceeded smoothly at room temperature with good yields and excellent regioselectivities.A mechanism involving a chloronium intermediate was proposed to explain the resulting regiochemistry.The current system explored a new type of nitrogen sources for aminohalogenation of functionalized olefins.

Magnetically recyclable Sm2Co17/Cu catalyst to chemoselectively reduce the 3-nitrostyrene into 3-vinylaniline under room temperature

Using non-noble metal catalysts to chemoselectively reduce the 3-nitrostyrene into 3-vinylaniline is extremely attractive due to the importantapplications of aromatic amines.However,the separation and recycle of catalytic particles to sustainably catalyze are still challenging on accountof their small size.In this communication,we report a novel magnetically recyclable catalyst of Sm2Co17/Cu to chemoselectively reduce3-nitrostyrene into 3-vinylaniline by activating ammonia borane(AB)to yield hydrogen.The Sm2Co17/Cu,composited of 180 nm Sm2Co17nano magnet and 10 nm Cu catalyst nano particles,shows a high conversi on(98%)and a high selectivity(99%)for 3-nitrostyrene under ultrasonic concussion.More importantly,they are easily collected by self-separation method without any magnetic field.As a consequenee,the excellent recyclable feature is acquired even underwent 10 cycles.Our approach provides a green strategy to synthesize magneticallyrecyclable catalysts.

Tailoring the surface structure of iron compounds to optimize the selectivity of 3-nitrostyrene hydrogenation reaction over Pt catalyst

Selective hydrogenation of substituted nitroarenes is an important reaction to obtain amines.Supported metal catalysts are wildly used in this reaction because the surface structure of supports can tune the properties of the supported metal nanoparticles(NPs)and promote the selectivity to amines.Herein,Pt NPs were immobilized on Fe OOH,Fe_(3)O_(4)andα-Fe_2O_(3)nanorods to synthesize a series of iron compounds supported Pt catalysts by liquid phase reduction method.Chemoselective hydrogenation of 3-nitrostyrene to 3-aminostyrene was used as probe reaction to evaluate the performance of the catalysts.The results show that Pt/Fe OOH exhibits the highest selectivity and activity.Fe OOH support with pores and-OH groups can tune the electronic structure of Pt NPs.The positive charge of Pt NPs supported on Fe OOH is key factor for improving the catalytic performance.

Highly efficient and anti-poisoning single-atom cobalt catalyst for selective hydrogenation of nitroarenes

Developing non-precious metal catalysts to selectively reduce functionalized nitroarenes with high efficiency is urgently desirable for the production of value-added amines.Herein,we report a novel,efficient,anti-poisoning single-atom cobalt catalyst(Co-NAC)for the highly selective hydrogenation of the nitro to amino group for nitroarenes baring various functional groups,including vinyl,cyano,and halogen.Using a combination of structure characterization techniques,we have confirmed that the cobalt species are predominantly present in the form of four-coordinated Co single sites anchored on nitrogen-assembly carbon(NAC)as the ordered mesoporous support.Co-NAC catalysts enable the full conversion and>99%selectivity with molecular H2 as a green reductant under mild conditions(80℃,2 MPa H2).As for the selective hydrogenation of 3-nitrostyrene,Co-NAC catalyst affords high catalytic productivity(19.7 h-1),which is superior to the cobalt nanoparticles(NPs)catalysts and most of the recently reported Co-based catalysts.This is attributed to the highly accessible atomically-dispersed Co active sites,the high surface area with ordered-mesoporous morphology and the prominent high content of nitrogen dopants.Notably,Co-NAC catalyst displays resistance towards sulfur-containing poisons(20 equivalents)and strong non-oxidizing acid(8 M),showing great potential for continuous application in the chemical industry.