- Development of TsDPEN based imine-containing ligands for the copper-catalysed asymmetric Kinugasa reaction
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A novel class of chiralN,N,Nimine-containing ligands derived from TsDPEN (N-(p-tosyl)-1,2-diphenylethylene-1,2-diamine) has been developed and applied to the copper-catalyzed asymmetric Kinugasa reaction. The copper(ii) salt proved to be an efficient catalyst precursor, and it provides an efficient way to synthesize enantioenrichedcis-β-lactam. The pathway is air-tolerant and easily manipulated, and the ligands are easy to synthesize. A working model is proposed in which the stereocontrolling step is the [2 + 2] cycloaddition between ketene and imine to explain the observed stereoselectivities.
- Deng, Ping,He, Feilong,He, Huakang,Wu, Yue,Xu, Chuanlong,Yang, Yuchen,Zhou, Hui
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p. 18107 - 18114
(2020/06/08)
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- Asymmetric synthesis of trans-β-lactams by a Kinugasa reaction on water
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The asymmetric Kinugasa reaction was performed on pure water for the first time without the need for any organic co-solvents. In contrast to most asymmetric Kinugasa reactions, trans-β-lactams were obtained as the major products in good yields, enantioselectivities, and diastereoselectivities (up to 90 % yield, 98 % ee, and >99:1 d.r.). This reaction is atom-economical, environmentally friendly, and affords synthetically useful but challenging products. Walking on water: Asymmetric Kinugasa reactions on pure water without any organic co-solvents afforded synthetically useful trans-β-lactams in good yields, enantioselectivities, and diastereoselectivities (up to 90 % yield, 98 % ee, and >99:1 d.r.). Copyright
- Chen, Zhenling,Lin, Lili,Wang, Min,Liu, Xiaohua,Feng, Xiaoming
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supporting information
p. 7561 - 7567
(2013/06/27)
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- Ytterbium(III) triflate-catalyzed stereoselective synthesis of β-lactams via [2 + 2] cyclocondensation in ionic liquid
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Catalyzed by ytterbium(III) triflate [Yb(OTf)3], β-lactams were stereoselectively synthesized from imines and acetyl chlorides in ionic liquid under mild conditions. The ionic liquid and catalyst could be recycled and reused as opposed to tradi
- Chen, Rener,Yang, Bingjian,Su, Weike
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p. 3167 - 3174
(2007/10/03)
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- Trisoxazoline/Cu(II)-promoted Kinugasa reaction. Enantioselective synthesis of β-lactams
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The reactions of nitrones with terminal alkynes, catalyzed by chiral iPr-trisoxazoline 23/Cu(ClO4)2·6H 2O under air atmosphere, afforded β-lactams in moderate to good yields with up to 85% ee. The diastereoselec
- Ye, Meng-Chun,Zhou, Jian,Tang, Yong
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p. 3576 - 3582
(2007/10/03)
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- Synthesis and antimicrobial activity of 1,3,4-triaryl-2-azetidinones
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A set of substituted 1,3,4-triaryl-2-azetidinones were synthesized and characterized. Their antimicrobial activity, against Gram+ and Gram- bacteria and Fungi, was tested. The compounds 23 and 30 showed remarkable activity against Pseudomonas aeruginosa.
- Diurno,Mazzoni,Piscopo,Bolognese
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p. 239 - 247
(2007/10/02)
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