Synthesis of Selenazoles by in Situ Cycloisomerization of Propargyl Selenoamides Using Oxygen–Selenium Exchange Reaction
摘要:
Herein, we describe an approach toward selenazole preparation based on the cycloisomerization of propargyl selenoamides. The selenoamides were synthesized in situ using the Ishihara reagent with spontaneous cyclization to form the 2,5-disubstituted selenazoles. Heterocylcles 9a-j were prepared using readily available starting materials, and yields ranged from moderate to good (20-80%). Methylselenazole 9a could be transformed into a bromomethyl derivative 13 using NBS. The intermediate 13 would provide a more versatile building block for further derivatizations, e.g., the cyanide 14.
Merging gold catalysis, organocatalytic oxidation, and Lewis acid catalysis for chemodivergent synthesis of functionalized oxazoles from N-propargylamides
作者:Shaoyu Mai、Changqing Rao、Ming Chen、Jihu Su、Jiangfeng Du、Qiuling Song
DOI:10.1039/c7cc05746f
日期:——
Novel catalytic systems consisting of cationicgold complexes, N-hydroxyphthalimide (NHPI), and transition-metal-based Lewis acids have been developed for the one-pot synthesis of functionalized oxazoles from N-propargylamides with excellent functional group tolerance. These transformations demonstrated the excellent compatibility of homogeneous goldcatalysis with organocatalytic oxidative carbon–nitrogen
Dual hydrogen bond donation, one from side-arm amide, and another from substrate or acid additive, enables Au(i)–Cl bond activation and gold(i)-catalysis.
Synthesis of acridones via Ir(iii)-catalyzed amination annulation of oxazoles with anthranils
作者:Han-Yi Zhou、Lin Dong
DOI:10.1039/d4ob00377b
日期:——
An unprecedented Ir(III)-catalyzed C-H activation/amination/annulation of 2-phenyloxazoles with anthranils for the highly selective preparation of acridone derivatives in one-pot under controlled conditions is reported. This protocol is characterized by atom...