Abstract
A palladium-catalyzed three-component reaction between 5-(2-chloroquinolin-3-yl) oxazoles, isocyanides, and water to yield 3-(oxazol-5-yl)quinoline-2-carboxamides is described. Interestingly, sulfonylation occurred when the same reaction was performed with toluenesulfonylmethyl isocyanide (TosMIC) as an isocyanide source. The reaction with 5-(2-chloroquinolin-3-yl)oxazoles and TosMIC in the presence of Cs2CO3 in DMSO afforded 5-(2-Tosylquinolin-3-yl)oxazoles. In basic media, TosMIC probably decomposed to generate Ts− species, which were replaced with Cl−. Tandem oxazole formation with subsequent sulfonylation of 2-chloroquinoline-3-carbaldehydes to form directly 5-(2-tosylquinolin-3-yl)oxazoles was also investigated.
Highlights
Quinolines are heterocyclic compounds exhibiting diverse and well-documented bioactivity and physical properties as well as existing as scaffolds in complex structures of natural products (Michael, 2002; Hranjec et al, 2017)
Nuclear magnetic resonance (NMR) spectra recorded on a Bruker AVANCE Spectrometer (400 MHz for 1H, 100 MHz for 13C) in DMSO-d6 and CDCl3 as solvent, TMS used as internal standard
The reaction of quinoline 3a with cyclohexyl isocyanide 4a was selected as a model reaction in the presence of
Summary
Quinolines are heterocyclic compounds exhibiting diverse and well-documented bioactivity and physical properties as well as existing as scaffolds in complex structures of natural products (Michael, 2002; Hranjec et al, 2017). Amides are especially valuable as precursors in synthesizing of bioactive and natural structures, in medicinal chemistry as well as protein synthesis (Bode, 2006; Rönn et al, 2008). Many natural products such as urukthapelstatin A have been isolated from marine sources, these contains, several aminocarbonyl and oxazole functional groups with cytotoxic activity against human lung cancer (Yu et al, 2009). Microcyclamide A is a cyclic hexapeptide with three fivemembered heterocycles It is isolated from cyanobacterium M. aeruginosa, and it has exhibited cytotoxic effects against P388 murine leukemia (Ishida et al, 2000; Davyt and Serra, 2010; Raveh et al, 2010) (Figure 1)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
