Role of <i>Ortho</i>-Substituents on Rhodium-Catalyzed Asymmetric Synthesis of β-Lactones by Intramolecular C–H Insertions of Aryldiazoacetates
作者:Liangbing Fu、Hengbin Wang、Huw M. L. Davies
DOI:10.1021/ol5011505
日期:2014.6.6
A rhodium-catalyzed asymmetric synthesis of β-lactones via intramolecular C–H insertion into the ester group of aryldiazoacetates has been developed. The β-lactones were synthesized in high yields and with high levels of diastereo- and enantioselectivity. Halo and trifluoromethyl substituents at the ortho position of the aryldiazoacetates enhance intramolecular C–H insertions over intermolecular reactions
Control of the regioselectivity of nucleophiles toward alkylating agents is a fundamental problem in heterocyclic chemistry. Substrate-controlled TfOH-catalyzed alkylation of 4-hydroxycoumarin with diazo compounds has been developed to provide rapid access to the C3- or O-alkylated 4-hydroxycoumarins with high efficiency. The regioselectivity can be determined by varying the electronic nature of the
PARTHENOLIDE DERIVATIVES, METHODS FOR THEIR PREPARATION AND THEIR USE AS ANTICANCER AGENTS
申请人:University Of Rochester
公开号:EP3003317A2
公开(公告)日:2016-04-13
[EN] PARTHENOLIDE DERIVATIVES, METHODS FOR THEIR PREPARATION AND THEIR USE AS ANTICANCER AGENTS<br/>[FR] DÉRIVÉS DE PARTHÉNOLIDE, LEURS PROCÉDÉS DE PRÉPARATION ET LEUR UTILISATION EN TANT QU'AGENTS ANTICANCÉREUX
申请人:UNIV ROCHESTER
公开号:WO2014197591A2
公开(公告)日:2014-12-11
Methods are provided for the generation of parthenolide derivatives functionalized at carbon atoms C9 and C14. Natural cytochrome P450 enzymes, and engineered variants of these enzymes, are used to carry out the hydroxylation of these sites in parthenolide. These P450-catalyzed C-H hydroxylation reactions are coupled to chemical interconversion of the enzymatically introduced hydroxyl group to install a broad range of functionalities at these otherwise unreactive sites of the molecule. The methods can also be used to produce bifunctionalized parthenolide derivatives, which in addition to modifications at the level of carbon atom C9 or C14, are also functionalized at the level of carbon atom C13.
Thermal Stability and Explosive Hazard Assessment of Diazo Compounds and Diazo Transfer Reagents
作者:Sebastian P. Green、Katherine M. Wheelhouse、Andrew D. Payne、Jason P. Hallett、Philip W. Miller、James A. Bull
DOI:10.1021/acs.oprd.9b00422
日期:2020.1.17
100 °C for the common diazo transfer reagent p-acetamidobenzenesulfonyl azide (p-ABSA). The Yoshida correlation is applied to DSC data for each diazocompound to provide an indication of both their impact sensitivity (IS) and explosivity. As a neat substance, none of the diazocompounds tested are predicted to be explosive, but many (particularly donor/acceptor diazocompounds) are predicted to be impact-sensitive