A photoredox-catalyzed radical addition of methylene-2-oxazolines has been developed under visible light irradiation to synthesize monofluorooxazoles with quaternary C–F centers using 2-bromo-2-fluoro-3-oxo-3-phenylpropionates as radical source.
Sequential Au/Cu Catalysis: A Two Catalyst One-Pot Protocol for the Enantioselective Synthesis of Oxazole α-Hydroxy Esters <i>via</i>
Intramolecular Cyclization/Intermolecular Alder-Ene Reaction
作者:Kumara Swamy Nalivela、Matthias Rudolph、Elham S. Baeissa、Basma G. Alhogbi、Ibraheem A. I. Mkhalid、A. Stephen K. Hashmi
DOI:10.1002/adsc.201800246
日期:2018.6.5
alkylglyoxylates 3 was developed. The first step of the one‐pot procedure is the selective intramolecular in situ formation of an alkylideneoxazoline 2, which then in an intermolecular reaction is enantioselectively transformed to the oxazole α‐hydroxy ester derivatives 4 in quantitative yield and good to excellent enantioselectivity via an asymmetric copper(II)‐catalyzed Alder‐enereaction.
Readily switchable one-pot 5-exo-dig cyclization using a palladium catalyst
作者:Jaishree K. Mali、Balaram S. Takale、Vikas. N. Telvekar
DOI:10.1039/c6ra25857c
日期:——
A convenient, ligand-free, Pd(OAc)2-catalyzed one-pot reaction has been developed for the synthesis of oxazolines and oxazoles from easily available acid chlorides and propargylamine. The reaction pathways could be easily modulated to selectively obtain oxazolines or oxazoles by merely changing the additives. This method proceeds via in situ sequential nucleophilic addition/elimination reactions followed
Oxazoles are pivotal structural scaffolds in coordination chemistry, natural products, medicinal chemistry, and material science.[1] Consequently, the synthesis of functionalized oxazoles with multiple pharmacological and biological properties has become the subject of intense research in recent decades.[2] The difluoromethylene group (CF2), which is a bioisostere for an oxygen atom, can significantly
Efficient Cycloisomerization of Propargyl Amides by Electrophilic Gold(I) Complexes of KITPHOS Monophosphines: A Comparative Study
作者:Simon Doherty、Julian G. Knight、A. Stephen K. Hashmi、Catherine H. Smyth、Nicholas A. B. Ward、Katharine J. Robson、Sophie Tweedley、Ross W. Harrington、William Clegg
DOI:10.1021/om1006769
日期:2010.9.27
Electrophilic gold(I) complexes of diphenyl- and dicyclohexylphosphino-based KITPHOSmonophosphines catalyze the 5-exo-dig cycloisomerization of a range of propargyl amides to afford the corresponding alkylidene oxazolines; in all cases catalysts formed from diphenylphosphino-substituted KITPHOSmonophosphines outperformed their dicyclohexylphosphino counterparts as well as that based on triphenylphosphine