A Simple and Effective Method for α-Hydroxylation of β-Dicarbonyl Compounds Using Oxone as an Oxidant without a Catalyst
作者:Jun Yu、Jian Cui、Chi Zhang
DOI:10.1002/ejoc.201000940
日期:2010.12
Oxone has been found to be a highly efficient reagent for the introduction of a hydroxy group at the α position of a variety of β-dicarbonylcompounds in the homogeneous solvent mixture of water and 1,4-dioxane at 60 °C.
已发现 Oxone 是一种高效试剂,可在 60 °C 下在水和 1,4-二恶烷的均相溶剂混合物中在各种 β-二羰基化合物的 α 位引入羟基。
Cerium-Catalyzed, Aerobic Oxidative Synthesis of 1,2-Dioxane Derivatives from Styrene and Their Fragmentation into 1,4-Dicarbonyl Compounds
1,4-Diketones were prepared by cerium-catalyzedoxidative coupling of styrene with molecular oxygen and 1,3-dicarbonyl compounds. This two-step sequence was performed as a one-pot procedure without isolation of the intermediate products. The first step is a metal-catalyzed radical reaction yielding 3-hydroxy-1,2-dioxane derivatives being the cyclotautomers of initially formed 4-hydroperoxy ketones
We report the metal-catalyzed α-hydroxylation of a variety of cyclic and acyclic β-dicarbonylcompounds by molecularoxygen. The decisive advantage of this new method is the use of catalytic amounts of the nontoxic cerium salt CeCl3·7H2O in 2-propanol at ambient temperature. Most of the cyclic substrates 4a−4i give high yields of analytically pure products 5a−5i, and the workup procedure is simple
Synthesis of α-Quaternary Bicyclo[1.1.1]pentanes through Synergistic Organophotoredox and Hydrogen Atom Transfer Catalysis
作者:Jeremy Nugent、Alistair J. Sterling、Nils Frank、James J. Mousseau、Edward A. Anderson
DOI:10.1021/acs.orglett.1c03346
日期:2021.11.5
Bicyclo[1.1.1]pentanes (BCPs) are important in drug design as sp3-rich bioisosteres of arenes and tert-butyl groups; however, the preparation of BCPs with adjacent quaternary carbons is barely known. We report a facile synthesis of α-quaternary BCPs using organophotoredox and hydrogen atom transfer catalysis in which α-keto radicals, generated through oxidation of β-ketocarbonyls, undergo efficient
The cerium-catalyzed C−C coupling reaction of carbo- and heterocyclic β-dicarbonylcompounds 1 with styrenes 4, using oxygen (air) as the oxidant, at ambient temperature, is reported. The reaction afforded a mixture of diastereoisomeric hydroperoxides 5 which could be transformed into the unique dioxo compounds 6 by disproportionation of the peroxo function under treatment with acetyl chloride/pyridine