- Metal free biomimetic deaminative direct C-C coupling of unprotected primary amines with active methylene compounds
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An unprecedented direct C-C coupling reaction of unprotected primary amines with active methylene compounds is reported. The reaction involves a biomimetic deamination of amines which was achieved under conditions free of metallic reagents and strong oxidizing agents. A wide range of primary amines was reacted with different active methylene compounds to provide structurally diverse trisubstituted alkenes and dihydropyridines. A kinetic study revealed an activation barrier of 10.1 kcal mol-1 for the conversion of a key intermediate of the reaction.
- Ghosh, Santanu,Jana, Chandan K.
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supporting information
p. 10153 - 10157
(2019/12/26)
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- Nickel(ii)-catalyzed enantioselective 1,3-dipolar cycloaddition of azomethine imines with alkylidene malonates
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We demonstrated an asymmetric 1,3-dipolar cycloaddition of azomethine betaines with alkylidene malonates by using a chiral N,N'-dioxide- NiII complex as a catalyst. Both aromatic- and aliphatic-substituted alkylidene malonates were found to be suitable for the reaction. A range of transpyrazolone derivatives was exclusively obtained with excellent yields (up to 99% yield) and good enantioselectivities (up to 97% ee) under mild reaction conditions. The reaction could be carried out on a gram scale with the good results being maintained. Control experiments were performed to elucidate the specific diastereoselectivity of the reaction. The formation of single trans isomers was dominated by secondary orbital interactions between the ester groups of the dipolarophile and the azomethine imine. On the basis of the experimental results and previous reports, a possible catalytic model was assumed.
- Li, Jiangting,Lian, Xiangjin,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
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supporting information
p. 5134 - 5140
(2013/07/05)
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- Chiral-Zn(NTf2)2-complex-catalyzed diastereo- and enantioselective direct conjugate addition of arylacetonitriles to alkylidene malonates
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Chiral N,N′-dioxide/Zn(NTf2)2 complexes were demonstrated to be highly effective in the direct asymmetric conjugate addition of arylacetonitriles to alkylidene malonates under mild conditions. A wide range of substrates were tolerated to afford their corresponding products in moderate-to-good yields with high diastereoselectivities (82:18->99:1 d.r.) and enantioselectivities (81-99 % ee). The reactions performed well, owing to the high Lewis acidity of the metal triflimidate and a ligand-acceleration effect. The N,N′-dioxide also benefited the deprotonation process as a Bronsted base. The catalytic reaction could be performed on the gram-scale with retention of yield, diastereoselectivity, and enantioselectivity. The products that contained functional groups were ready for further manipulation. In addition, a possible catalytic model was proposed to explain the origin of the asymmetric induction. Copyright
- Yao, Jingjing,Liu, Xiaohua,He, Peng,Zhu, Yin,Lian, Xiangjin,Lin, Lili,Feng, Xiaoming
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supporting information
p. 16424 - 16430
(2013/12/04)
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- Synthesis of novel 2, 5-dihydrofuran derivatives and evaluation of their anticancer activity
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According to metal-catalyzed [3 + 2] cycloaddition reaction, we synthesized a series of novel 2, 5-dihydrofuran derivatives and evaluated their in vitro anti-cancer activities via MTT method. The bioassay showed that the majority of the resultant compounds exerted anti-tumor effect against four human cancer cell lines to various extents, which supported the rationale of the design. Compounds 9e and 10g showed the highest activity with broad anti-cancer spectrum, which were good candidates for further evaluation.
- Zhang, Yikai,Zhong, Hanyu,Wang, Tiantian,Geng, Dongping,Zhang, Mingfeng,Li, Ke
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scheme or table
p. 69 - 80
(2012/03/26)
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- Synthesis and anti-tumor activity of novel ethyl 3-aryl-4-oxo-3,3a,4,6- tetrahydro-1H-furo[3,4-c]pyran-3a-carboxylates
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A series of ethyl 3-aryl-4-oxo-3,3a,4,6-tetrahydro-1H-furo[3,4-c]pyran-3a- carboxylates were prepared through the metal-catalyzed domino reaction of alkylidene malonates and 1,4-butynediol under a one-pot reaction condition at room temperature. Their in vitro anti-proliferative activities were subsequently evaluated in A549, QGY and HeLa cells. The majority of the compounds showed potent anti-tumor activity against HeLa cells. In particular, compound 3l was the most potent compound with IC50 value of 5.4 μM. For the first time, the X-ray structure of the anti-tumor ethyl 3-aryl-4-oxo-3,3a,4,6- tetrahydro-1H-furo[3,4-c]pyran-3a-carboxylates is determined.
- Wang, Tiantian,Liu, Jia,Zhong, Hanyu,Chen, Huan,Lv, Zhiliang,Zhang, Yikai,Zhang, Mingfeng,Geng, Dongping,Niu, Chunjuan,Li, Yongmei,Li, Ke
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scheme or table
p. 3381 - 3383
(2011/06/24)
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- A convenient synthesis of 3-arylbutanolides and 3-arylbutenolides
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A series of 3-aryl-substituted butenolides and butanolides has been prepared in a common short synthetic sequence from the corresponding aryl aldehydes. The 3-arylbutanolides are prepared by cyclisation of 3-aryl-3- cyano-1-propanols, obtained by selectiv
- Gu, Jian-Xin,Holland, Herbert L.
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p. 3305 - 3315
(2007/10/03)
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