An effective route to pyrrolo[1,2-a]pyrazines is described via reaction of ethylenediamine,acetylenic esters and nitrostyrene derivatives in the presence of 20 mol%of sulfamic acid.
A simple and efficient synthetic protocol has been developed using a one-pot, three-component reaction involving 2-amino phenols, dialkyl acetylene dicarboxylates and nitrostyrene derivatives. Utilizing this protocol,...A simple and efficient synthetic protocol has been developed using a one-pot, three-component reaction involving 2-amino phenols, dialkyl acetylene dicarboxylates and nitrostyrene derivatives. Utilizing this protocol, a variety of novel pyrrolo-1,4-benzoxazine derivatives were synthesized in excellent yields.展开更多
Simple pyrrolidine-azole conjugates have been synthesized and found to be efficient catalysts for asymmetric Michael addition to nitrostyrenes. The identified optimal catalysts, pyrrolidine-azoles 2, 8 and 13, could c...Simple pyrrolidine-azole conjugates have been synthesized and found to be efficient catalysts for asymmetric Michael addition to nitrostyrenes. The identified optimal catalysts, pyrrolidine-azoles 2, 8 and 13, could catalyze the asymmetric Michael addition of a range of Michael donors and nitrostyrenes in high yields (up to 99%) and excellent stereoselectivities (up to 99:1 dr and 97% ee).展开更多
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 catal...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.展开更多
Two hydrogen-bonding adsorbents-macroporous crosslinked poly(p-nitrostyrene) and poly(p-vinylbenzyl amide)--were synthesized, and the absorption property of phenol from cyclohexane solution onto the adsorbents was stu...Two hydrogen-bonding adsorbents-macroporous crosslinked poly(p-nitrostyrene) and poly(p-vinylbenzyl amide)--were synthesized, and the absorption property of phenol from cyclohexane solution onto the adsorbents was studied. The differential adsorption heats for varied adsorption capacities calculated from the adsorption isotherms according to the Clapeyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol). The adsorption capacity of o-nitrophenol in cyclohexane was much less than that of phenol under the same condition. The adsorption capacity of phenol from cyclohexane onto polyacrylonitile was much less than that onto poly(p-nitrostyrene) or poly(p-vinylbenzyl amide). All these results revealed that adsorption of phenol from cyclohexane by poly(p-nitrostyrene) or poly(p-vinylbenzyl amide) is based on hydrogen-bonding.展开更多
<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 s...<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展开更多
文摘An effective route to pyrrolo[1,2-a]pyrazines is described via reaction of ethylenediamine,acetylenic esters and nitrostyrene derivatives in the presence of 20 mol%of sulfamic acid.
文摘A simple and efficient synthetic protocol has been developed using a one-pot, three-component reaction involving 2-amino phenols, dialkyl acetylene dicarboxylates and nitrostyrene derivatives. Utilizing this protocol, a variety of novel pyrrolo-1,4-benzoxazine derivatives were synthesized in excellent yields.
基金supported by the National Natural Science Foundation of China (20421202, 20632060 and 20702052)the Ministry of Science and Technology of China (2008CB617501 and 2009ZX09501-018) and the Chinese Academy of Sciences.
文摘Simple pyrrolidine-azole conjugates have been synthesized and found to be efficient catalysts for asymmetric Michael addition to nitrostyrenes. The identified optimal catalysts, pyrrolidine-azoles 2, 8 and 13, could catalyze the asymmetric Michael addition of a range of Michael donors and nitrostyrenes in high yields (up to 99%) and excellent stereoselectivities (up to 99:1 dr and 97% ee).
基金The work was supported by the National Natural Science Foundation of China(Nos.51701109 and 51806115)Natural Science Foundation of Beijing Municipality,China(No.2192007)+3 种基金the China Postdoctoral Science Foundation(No.2018M641132)International S&T Cooperation Program of China(No.2015DFG52020),Key Program of National Natural Science Foundation of China(51331003)Program of Disciplines Construction in Beijing(No.PXM2019_014204_500031).
文摘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.
基金Supported by the National Natural Science Foundation of China !(Grant No. 29574164 and 29974015)
文摘Two hydrogen-bonding adsorbents-macroporous crosslinked poly(p-nitrostyrene) and poly(p-vinylbenzyl amide)--were synthesized, and the absorption property of phenol from cyclohexane solution onto the adsorbents was studied. The differential adsorption heats for varied adsorption capacities calculated from the adsorption isotherms according to the Clapeyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol). The adsorption capacity of o-nitrophenol in cyclohexane was much less than that of phenol under the same condition. The adsorption capacity of phenol from cyclohexane onto polyacrylonitile was much less than that onto poly(p-nitrostyrene) or poly(p-vinylbenzyl amide). All these results revealed that adsorption of phenol from cyclohexane by poly(p-nitrostyrene) or poly(p-vinylbenzyl amide) is based on hydrogen-bonding.
基金Project supported by the National Natural Science Foundation of China. This paper was reported at CHAC, Kobe, Japan, 1987.
文摘<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
