- Enantioselective dearomative [3+2] annulation of 5-amino-isoxazoles with quinone monoimines
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The first enantioselective dearomative [3+2] annulation of 5-amino-isoxazoles with quinone monoimines was realized using a chiral phosphoric acid as catalyst. Various novel (bridged) isoxazoline fused dihydrobenzofurans bearing two continuous quaternary stereocenters were achieved in moderate to good yields (up to 94%) with moderate to good enantioselectivities (up to 98% ee). The absolute configurations of two products were assigned by X-ray crystal structural analyses and a plausible reaction mechanism was proposed. This journal is
- Liu, Hui,Yan, Yingkun,Zhang, Jiayan,Liu, Min,Cheng, Shaobing,Wang, Zhouyu,Zhang, Xiaomei
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supporting information
p. 13591 - 13594
(2020/11/17)
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- Synthesis of Novel Pterocarpen Analogues via [3?+?2] Coupling-Elimination Cascade of α,α-Dicyanoolefins with Quinone Monoimines
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By employing triethylamine as a catalyst, [3?+?2] coupling-elimination cascade of α,α-dicyanoolefins with quinone monoimines was realized. The reactions afforded various novel pterocarpen analogues with generally moderate yields (up to 75%). In addition, a plausible reaction mechanism was proposed.
- Chen, Hui,Zhao, Sihan,Cheng, Shaobing,Dai, Xingjie,Xu, Xiaoying,Yuan, Weicheng,Zhang, Xiaomei
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p. 1672 - 1683
(2019/04/08)
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- Enantioselective Arylation of 3-Carboxamide Oxindoles with Quinone Monoimines and Synthesis of Chiral Spirooxindole-benzofuranones
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A highly enantioselective arylation of 3-carboxamide oxoindoles with quinone monoimines is described. Various 3-aryl-3-carboxamide oxindoles with an all-carbon quaternary center were obtained in moderate to good yields (up to 99%) with moderate to good enantioselectivities (up to 98%) in the presence of a bifunctional thiourea-tertiary amine catalyst. The absolute configuration of one product was determined by an X-ray crystal structural analysis and the absolute configurations of the other products can be assigned by analogy. Moreover, several chiral spirooxindole-benzofuranones were synthesized from the 3-aryl-3-carboxamide oxindoles in moderate yields with moderate to good enantioselectivities.
- Chen, Hui,Liu, Hui,Zhao, Si-Han,Cheng, Shao-Bing,Xu, Xiao-Ying,Yuan, Wei-Cheng,Zhang, Xiao-Mei
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supporting information
p. 1067 - 1072
(2019/05/24)
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- Discovery of 4-amino-2-(thio)phenol derivatives as novel protein kinase and angiogenesis inhibitors for the treatment of cancer: Synthesis and biological evaluation. Part II
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A novel series of 4-amino-2-(thio)phenol derivatives were well synthesized. The preliminary biological test revealed that several compounds displayed high specific protein kinase and angiogenesis inhibitory activities compared with previous work mainly because of the substitution of sulfonamide structure for amide fragment. Among which, compound 5i was identified to inhibit protein kinase B/AKT (IC50 = 1.26 μM) and ABL tyrosine kinase (IC 50 = 1.50 μM) effectively. Meanwhile, compound 5i demonstrated competitive in vitro antiangiogenic activities to Pazopanib in both human umbilical vein endothelial cell (HUVEC) tube formation assay and the rat thoracic aorta rings test.
- Xu, Fuming,Zhang, Lei,Jia, Yuping,Wang, Xuejian,Li, Xiaoguang,Wen, Qingli,Zhang, Yingjie,Xu, Wenfang
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p. 191 - 200
(2013/10/01)
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- Sulfonamide synthesis via oxyma-O-sulfonates - Compatibility to acid sensitive groups and solid-phase peptide synthesis
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A milder and more efficient procedure for the synthesis of sulfonamides by activating sulfonic acid groups as the corresponding sulfonate esters of ethyl 2-cyano-2-(hydroxyimino)acetate (Oxyma) is reported. This method is greener than all other existing protocols for the purpose. Other important advantages lie in (a) its applicability to less nucleophilic anilines under ambient and milder conditions and (b) its compatibility with solid phase peptide synthesis and acid-labile groups such as trityl (Trt) and tBu, which empowers the solid phase synthesis of sulfonamides of various peptides. To illustrate this, the syntheses of three sulfonamide derivatives of the peptide GAILG-NH2, which is relevant in the context of drug design against type 2 diabetes, are demonstrated by using Fmoc-based solid-phase peptide synthesis (SPPS). The activation of sulfonic acids as their corresponding O-sulfonate esters facilitates sulfonamide synthesis, which can be applied to those substrates that possess acid-labile functional groups and is compatible with solid phase synthesis. Copyright
- Palakurthy, Nani Babu,Dev, Dharm,Rana, Shubhasmin,Nadimpally, Krishna Chaitanya,Mandal, Bhubaneswar
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p. 2627 - 2633
(2013/06/04)
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- [[(4-Aminophenyl)sulfonyl]amino]phenyl phosphorodiamidates
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[[(4-Aminophenyl)sulfonyl]amino]phenyl phosphorodiamidates are useful as inhibitors of the enzyme urease as well as being effective antimicrobial agents.
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