A highly regioselective and enantioselective N-alkylation of isoxazol-5-ones with para-quinone methides promoted by bi-functional squaramide catalysts was developed. This unexpected asymmetric N-addition of isoxazolinones afforded a series of enantioenriched N-diarylmethane substituted isoxazolinones with high yields and enantioselectivities (up to 97 : 3 er). This reaction not only provides a useful
Highly strained 2H‐azirines with a tetrasubstituted stereocenter were synthesized by the enantioselective isomerization of isoxazoles with a chiral diene–rhodium catalyst system. The effect of ligands and the coordination behavior support the proposed catalytic cycle in which the coordination site is fixed in favor of efficient enantiodiscrimination by a bulky substituent of the ligand. In silico studies
Gold vs Light: Chemodivergent Reactivity of Diazoesters toward 2<i>H</i>-Azirine-2-carboxylic Acids
作者:Gleb D. Titov、Grigory I. Antonychev、Mikhail S. Novikov、Alexander F. Khlebnikov、Elizaveta V. Rogacheva、Liudmila A. Kraeva、Nikolai V. Rostovskii
DOI:10.1021/acs.orglett.3c00823
日期:2023.4.21
reaction is N-selective and produces 1,3-oxazin-6-ones, whereas a blue light activation leads to O–H insertion products, azirine-2-carboxylic esters. The observed chemodivergence is explained by the metal-bound and metal-free carbenes exhibiting different electronic properties in these reactions. In addition, a high antibacterial potential of the 1,3-oxazin-6-ones synthesized is shown.
Triazolylstyryl-Verbindungen sowie deren Verwendung zum Weisstönen organischer Materialien
申请人:BAYER AG
公开号:EP0010607A1
公开(公告)日:1980-05-14
Zum Weißtönen von Polyestermaterialien eignen sich vorzüglich Triazolylstyrylverbindungen der Formel
in welcher
R1 und R2 Wasserstoff, Halogen, Alkyl, Cycloalkyl, Aralkyl, Styryl oder Aryl bedeuten und der
Ring A gegebenenfalls substituiert oder mit einem weiteren Benzoring anelliert ist.
式中 R1 和 R2 为氢、卤素、烷基、环烷基、芳烷基、苯乙烯基或芳基,环 A 被另一个苯环任选取代或融合的三唑基苯乙烯基化合物尤其适用于增白聚酯材料。