Pyrenediones (PYDs) are efficient photocatalysts for three oxygenation reactions: epoxidation of electron deficient olefins, oxidative hydroxylation of organoborons, and oxidation of sulfides via in situgeneration of H2O2 under visible light irradiation, using oxygen as a terminal oxidant and IPA as a solvent and a hydrogen donor.
吡咯二酮(PYDs)是用于三种氧化反应的有效光催化剂:缺电子烯烃的环氧化,有机硼的氧化羟基化以及在可见光照射下通过原位生成H 2 O 2,使用氧作为末端氧化剂和IPA作为硫化物的氧化溶剂和氢供体。
Ultrasound-assisted rapid synthesis of β-cyanoepoxides using hypervalent iodine reagents
作者:Fateh V. Singh、Saeesh R. Mangaonkar、Priyanka B. Kole
DOI:10.1080/00397911.2018.1479760
日期:2018.9.2
Abstract An elegant approach for the rapid synthesis of β-cyanoepoxides 3 by the epoxidation of β-cyanostyrenes 1 with PIDA 2a is described. The epoxidation of β-cyanostyrenes 1 was performed with 1.2 equiv. of PIDA 2a in MeCN-H2O (1:1) at room temperature in ultrasonic bath. The epoxidation reactions were completed in short reaction time and β-cyanoepoxides 3 were isolated in 69–94% yields. Graphical
The first enantioselective epoxidation of readily available alkylidenemalononitriles has been developed by using a multifunctional cinchona derived thiourea as the organocatalyst and cumyl hydroperoxide as the oxidant. A new simple one-pot asymmetric epoxidation/S(N)2 ring-opening reaction with 1,2-diamines leading to important enantioenriched heterocycles, i.e. 3-substituted piperazin-2-ones, has been established.