1186503-01-4Relevant academic research and scientific papers
Development of TsDPEN based imine-containing ligands for the copper-catalysed asymmetric Kinugasa reaction
Deng, Ping,He, Feilong,He, Huakang,Wu, Yue,Xu, Chuanlong,Yang, Yuchen,Zhou, Hui
, p. 18107 - 18114 (2020/06/08)
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.
Asymmetric synthesis of trans-β-lactams by a Kinugasa reaction on water
Chen, Zhenling,Lin, Lili,Wang, Min,Liu, Xiaohua,Feng, Xiaoming
supporting information, p. 7561 - 7567 (2013/06/27)
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
Enantioselective synthesis of β-lactams via the IndaBox-Cu(II)-catalyzed Kinugasa reaction
Saito, Takao,Kikuchi, Tomohiro,Tanabe, Hiroaki,Yahiro, Junichi,Otani, Takashi
supporting information; experimental part, p. 4969 - 4972 (2009/12/06)
The enantioselective Kinugasa reaction of nitrones with terminal alkynes in the presence of 20 mol % of IndaBox-Cu(OTf)2 and di-sec-butylamine (1.5 equiv) produced β-lactams with the highest level of enantiomeric excesses among the catalytic en
Reductive Ring Contraction of Mesoionic Thiazol-4-ones to Azetidin-2-ones
Sheradsky, Tuvia,Zbaida, David
, p. 2165 - 2169 (2007/10/02)
A series of anhydro-2,3,5-triaryl-4-hydroxythiazolium hydroxides was prepared and desulfurized with Raney nickel.The reduction was stereospecific and gave cis-1,3,4-triphenylazetidin-2-ones.Desulfurization in the presence of triphenylphosphine gave the corresponding trans-azetidinones.Consideration of the possible mechanistic pathways led to the conclusion that the reaction proceeds through formation of biradical-dipole, hydrogenation to a 1,4-dipole, and ring closure.It was also concluded that in the preparation of β-lactams by the nonconcerted cycloaddition of imines and ketenes the first step (dipole formation) is the stereochemistry-determining step.
