α-proton in the cyclization process. The acidity dependence of the cyclization reactions and 13C NMR studies of a model compound, methyl cyanoacetate, in various acidic media were consistent with the involvement of the O,N-diprotonated dication of methyl cyanoacetate, a distonic dication, in strong acid, and this is considered to be the de facto electrophile in the present cyclization reaction of arylcyanopropionates
我们介绍了芳基氰基丙酸酯的超强酸催化的分子内环化反应,以中等至高收率得到环化的五元和六元β-烯胺酯。质子化的腈与芳族碳原子的已知分子内闭环反应限于6元情况。有趣的是,观察到的氰基官能度反应性的显著协同增加,和氰基的氮原子被转化成氨基,当酯基存在于一个孪位的布置。氘交换实验排除了α-质子去质子化在环化过程中的参与。环化反应和13的酸度依赖性在各种酸性介质中对模型化合物氰基乙酸甲酯的13 C NMR研究与强酸中氰基乙酸甲酯的O,N-二质子化指示剂(二元体指示剂)在强酸中的参与一致,这被认为是事实上的亲电子试剂。在本发明的芳基氰基丙酸酯的环化反应中。
[EN] E-ISOMERIC beta-AROMATIC OR HETEROAROMATIC SUBSTITUTED beta-ACYLAMINO-ACRYLATES AND METHODS OF PREPARING THE SAME<br/>[FR] DOLLAR G(B)-ACYLAMINO-ACRYLATES E-ISOMERES A SUBSTITUTION DOLLAR G(B)-AROMATIQUE OU HETEROAROMATIQUE ET LEUR PROCEDES DE PREPARATION
申请人:DSM IP ASSETS BV
公开号:WO2004011414A1
公开(公告)日:2004-02-05
E-isomeric ß-(hetero) aromatically substituted acylaminoacrylates are of great economic interest since with them, by means of hydration, precursors of appropriately substituted (ß-amino acids can be prepared and, by doing so, lead to higher enantio-selectivities than the corresponding Z-isomers. The invention describes novel E-isomeric R-aromatically or ß-heteroaromatically substituted ß-acylaminoacrylates of the general formula (I): in which R represents hydrogen or a substituted or unsubstituted alkyl or aromatic or heteroaromatic residue, and R' represents a substituted or unsubstituted aromatic or heteroaromatic residue, R' represents H, a substituted or unsubstituted alkyl or aromatic or heteroaromatic residue, and R'' represents H, a substituted or unsubstituted alkyl, acyl, aromatic or heteroaromatic residue. According to the invention, the compounds according to the general formula (I) are prepared by acylation at temperatures below the boiling point of the reaction mixture.
PhIO/Et<sub>3</sub>N ⋅ 3HF-Mediated Formation of Fluorinated 2<i>H</i>-Azirines via Domino Fluorination/Azirination Reaction of Enamines
作者:Yong Zhang、Xiaoyuan Zhao、Chen Zhuang、Senlin Wang、Daisy Zhang-Negrerie、Yunfei Du
DOI:10.1002/adsc.201800124
日期:2018.6.5
enaminones were converted to the biologically interesting fluorinated 2H‐azirines through reactions with PhIF2 generated in situ by PhIO and Et3N ⋅ 3HF in 1,2‐dichroloethane, which features the hypervalent iodine reagents‐mediated introduction of fluorine atom and formation of the 2H‐azirine skeleton under metal‐free conditions. The domino reaction is postulated to proceed via a PhIF2‐mediated oxidative
<i>in</i>
<i>situ</i>
Formation of RSCl/ArSeCl and Their Oxidative Coupling with Enaminone Derivatives Under Transition‐metal Free Conditions
作者:Zhenhua Shang、Qingyu Chen、Linlin Xing、Yilin Zhang、Laura Wait、Yunfei Du
DOI:10.1002/adsc.201900940
日期:2019.11.5
The reaction of diorganyl disulfides or diselenides with PhICl2 in DMF at room temperature led to the in situ formation of the reactive organosulfenyl chloride (RSCl) or selenenyl chloride (ArSeCl), which reacted with enaminone compounds to afford a series of α‐thioenaminones or α‐selenylenaminones, respectively, including the bioactive inhibitor for Cdc25B and its analogue, via the intermolecular