Synthesis and biological activities of [E]-5-(2-acylvinyl)uracils
摘要:
The synthesis of a number of 5-substituted uracils, eg [E]-5-(2-acylvinyl)uracils 8a-8g is described. These compounds were found to have cytotoxic activities against CCRF-CEM human lymphoblastoid cells, HT-29 colon carcinoma cells and L1210/0 mouse leukemia cells. These compounds were also found to inhibit thymidylate synthase.
The Iridium-catalyzed enantioselective couplingreaction of vinyl azides and allylic electrophiles is presented and provides access to β-chiral carbonyl derivatives. Vinyl azide are used as acetamide enolate or acetonitrile carbanion surrogates, leading to γ,δ-unsaturated β-substituted amides as well as nitriles with excellent enantiomeric excess. The products are readily transformed into chiral N-containing
Remarkably simple IrIII catalysts enable the isomerization of primary and sec‐allylicalcohols under very mild reaction conditions. X‐ray absorption spectroscopy (XAS) and mass spectrometry (MS) studies indicate that the catalysts, with the general formula [Cp*IrIII], require a halide ligand for catalytic activity, but no additives or additional ligands are needed.
非常简单的Ir III催化剂可在非常温和的反应条件下实现伯醇和仲烯丙基醇的异构化。X射线吸收光谱(XAS)和质谱(MS)研究表明,通式为[Cp * Ir III ]的催化剂需要卤化物配体才能发挥催化活性,但不需要添加剂或其他配体。
Olefin Oxyamination with Unfunctionalized
<i>N</i>
‐Alkylanilines
作者:Shuang Gao、Meike Niggemann
DOI:10.1002/adsc.201801407
日期:2019.4
N‐Alkylanilines have rarely been used in oxyamination reactions, due to the normally necessary pre‐functionalization of the N‐atom. Also, the formation of aminium radical cations (ARCs) of anilines bearing alkyl substituents is plagued by the ARC's tendency to instantaneously convert to α‐aminoradicals or iminium ions. We present a readily available reagent combination that addresses both challenges
Highly diastereo- and enantio-selective epoxidation of secondary allylic alcohols catalyzed by styrene monooxygenase
作者:Hui Lin、Yan Liu、Zhong-Liu Wu
DOI:10.1039/c0cc04360e
日期:——
Enantiomerically enriched glycidol derivatives with contiguous stereogenic centers were obtained in a highly diastereo- and enantio-selective epoxidation catalyzed with the styrene monooxygenase StyAB2.
Palladium-catalyzed regioselective synthesis of B(4,5)- or B(4)-substituted <i>o</i>-carboranes containing α,β-unsaturated carbonyls
作者:Chuyi Zhang、Qian Wang、Song Tian、Jianwei Zhang、Jiaoyi Li、Ling Zhou、Jian Lu
DOI:10.1039/d0ob00698j
日期:——
With the help of a carboxylic acid directing group, Pd-catalyzed regioselective synthesis of B(4,5)- or B(4)-substituted o-carboranes containingα,β-unsaturated carbonyls has been reported. The –COOH, removed during the course of the reaction, is responsible for controlling the regioselectivity. The desired products could be obtained in moderate to good yields.