698-16-8Relevant articles and documents
Highly regioselective dipolar cycloadditions of nitrile oxides with α,β-acetylenic aldehydes
Jiang, Longqiang,Gao, Tao,Li, Zhi,Sun, Shaofa,Kim, Claudia,Huang, Changfeng,Guo, Haibing,Wang, Jian,Xing, Yalan
, p. 712 - 714 (2016)
1,2-Oxazol derivatives 3 were prepared by a highly regioselective 1,3-dipolar cycloaddition of nitrile oxides and α,β-acetylenicaldehydes 1 in good yields. Reactive nitrile oxides were generated in situ from stable chloro-oxime reagents 2 and triethyl ami
Design and synthesis of sinomenine isoxazole derivatives via 1,3-dipolar cycloaddition reaction
Pan, Hongmei,Lu, Tong,Wu, Xuedan,Gu, Chengwen,Tao, Naili,Zhang, Biao,Wang, Ao,Chen, Guangmei,Zhang, Kehua,Cheng, Jie,Jin, Jie
, p. 2360 - 2364 (2019/11/11)
A novel structure of sinomenine isoxazole derivatives is synthesised from sinomenine hydrochloride and aromatic aldehydes and requires six steps. 19 target compounds have been obtained in good yields. The sinomenine hydrochloride transforms to 4-alkynyl sinomenine, which is a key intermediate product to synthesise the target sinomenine isoxazole compounds, after a neutralisation reaction with ammonia and substitution reaction with 3-chloropropyne. Another key intermediate product is 1,3-dipole, which can be obtained from aromatic aldehyde. After treatment with hydroxylamine hydrochloride and then sodium carbonate solution, aromatic aldehyde is converted to aldehyde oxime, which reacts with N-chlorosuccinimide (NCS) to afford aryl hydroximino chloride. 1,3-Dipole is eventually formed in situ while triethylamine (TEA) in DMF is added dropwise. Then 4-alkynyl sinomenine is added to provide the sinomenine isoxazole derivative via 1,3-dipolar cycloaddition reaction as the key step. All the target compounds are characterised by melting point, 1H NMR, 13C NMR, HRMS and FT-IR spectroscopy.
Ru-Catalyzed [3 + 2] Cycloaddition of Nitrile Oxides and Electron-Rich Alkynes with Reversed Regioselectivity
Feng, Qiang,Huang, Hai,Sun, Jianwei
, p. 2431 - 2436 (2021/05/05)
Polarity reversal ("umpolung") of a functional group can override its inherent reactivity and lead to distinct bond-forming modes. Herein we describe a rarely studied cycloaddition between nitrile oxides and electron-rich alkynes with reversed regioselect
