Synthesis of Exclusively 4-Substituted β-Lactams through the Kinugasa Reaction Utilizing Calcium Carbide
作者:Abolfazl Hosseini、Peter R. Schreiner
DOI:10.1021/acs.orglett.9b01192
日期:2019.5.17
A new Kinugasa reaction protocol has been elaborated for the one-pot synthesis of 4-substituted β-lactams utilizing calcium carbide and nitrone derivatives. Calcium carbide is thereby activated by TBAF·3H2O in the presence of CuCl/NMI. The ease of synthesis and use of inexpensive chemicals provides rapid access of practical quantities of β-lactams exclusively substituted at position 4.
One-pot synthesis of <i>trans</i>-<font>β</font>-lactams from ferrocenylketene generated by thermal Wolff rearrangement
作者:Mingshun Liu、Jian’an Wang、Xiaoxi Yuan、Rong Jiang、Nanyan Fu
DOI:10.1080/00397911.2017.1378358
日期:2017.12.17
ABSTRACT A series of β-lactams containing the ferrocene moiety were synthesized through the Staudinger reaction between ferrocenylketene generated by the thermal Wolff rearrangement of the corresponding diazo ketone and various imines. The stereochemical outcome has been investigated and the trans-products were isolated as the main products, opposite to the reported results by Bonini and coworkers
摘要 通过相应重氮酮的热沃尔夫重排产生的二茂铁基烯酮与各种亚胺之间的施陶丁格反应合成了一系列含有二茂铁部分的β-内酰胺。立体化学结果已被研究,反式产物作为主要产物被分离出来,这与 Bonini 和同事报告的结果相反。(±)-trans-1,4-diphenyl-3-ferrocenylazetidin-2-one (3c) 的绝对构型通过 X 射线分析确定。从反应机理的角度讨论立体选择性。图形概要
Remarkable ketene substituent dependent effect of photo irradiation on the diastereoselectivity in the Staudinger reaction
作者:Zhanhui Yang、Jiaxi Xu
DOI:10.1016/j.tetlet.2011.12.003
日期:2012.2
Controlling diastereoselectivity is a challenging issue in the Staudinger reaction. The influence of ultraviolet irradiation on the stereoselectivity in the Staudinger reaction has been investigated. The results indicate that ultraviolet irradiation is one of the most important means to regulate the diastereoselectivity of the products in the Staudinger reaction, whatever ketenes were generated from
N,N-Dimethylphosphoramidic dichloride: a convenient reagent for the preparation of β-lactams from acetic acids and imines
作者:Fernando P Cossío、Iñaki Ganboa、Jesús M García、Begoña Lecea、C Palomo
DOI:10.1016/s0040-4039(00)96016-7
日期:1987.1
A convenient reagent for the preparation of β-lactams from aceticacids and imines is described. A new route to α-keto-β-lactams from 3-bis(ethylthio)β-lactams is also reported. Reaction of 4-acethyl-β-lactams with diazomethane is also made.
Ring splitting of azetidin-2-ones via radical anions
作者:Raúl Pérez-Ruiz、Jose A. Sáez、Luis R. Domingo、M. Consuelo Jiménez、Miguel A. Miranda
DOI:10.1039/c2ob26528a
日期:——
The radicalanions of azetidin-2-ones, generated by UV-irradiation in the presence of triethylamine, undergo ring-splitting via N–C4 or C3–C4 bond breaking, leading to open-chain amides. This reactivity diverges from that found for the neutral excited states, which is characterised by α-cleavage. The preference for β-cleavage is supported by DFT theoretical calculations on the energy barriers associated