Effective transformation of aldoximes to nitriles by dehydration with 2-methylene-1,3-dioxepane in the presence of a Lewis acid catalyst
摘要:
The dehydration of aldoximes with 2-methylene-1,3-dioxepane (MDO) proceeds smoothly in the presence of a catalytic amount of Lewis acid such as scandium(III) triflate to give corresponding nitriles in moderate to high yields under mild conditions. (C) 1997 Elsevier Science Ltd.
isoxazoline heterocycles that have similar structural features to the commercially used phenylpyrazole, fipronil. Synthesis of the appropriately substituted styrenes and phenylacetylenes is followed by 1,3-dipolar cycloaddition reaction with several aliphatic nitrile oxides, which are prepared in situ from aldoximes with bleach. Relative reaction rates were determined for these specialized alkene and
Hexabromoacetone (HBA) was efficiently used for the protection of alcohols and aldehydes and deprotection of benzaldehyde dimethyl acetal, solketal, and other acetals and ketals. In only 10 min, the protection of glycerol yielded 90% of solketal and protection of benzaldehyde gave 95% of benzaldehyde dimethyl acetal. The deprotection of benzaldehyde dimethyl acetal under UV irradiation gave over 90%
In Situ Generation of Nitrile Oxides from NaCl–Oxone Oxidation of Various Aldoximes and Their 1,3-Dipolar Cycloaddition
作者:Guodong Zhao、Lixin Liang、Chi Ho Ethan Wen、Rongbiao Tong
DOI:10.1021/acs.orglett.8b03829
日期:2019.1.4
generation of nitrileoxides through NaCl/Oxone oxidation of aldoximes and their dipolar cycloaddition. The key feature is the use of a green chemistry approach to address the substrate scope of aldoximes: broad scope (aliphatic, aromatic, and alkenyl aldoximes) without production of organic byproducts derived from oxidant and/or catalyst. Importantly, NaCl/Oxone-promoted three-component cycloaddition of aldehyde
anti-influenza drug targeting the virus neuraminidase. The (3 + 2) cycloaddition reaction of 2-ethylbutanenitrile oxide with the cyclopentene dipolarophile derived from Vince lactam is a key step in the conventional synthesis of peramivir. Our study showed that conducting the (3 + 2) cycloaddition reactions with either aliphatic or aromatic nitrile oxide in hexane solution provided high percentage of the desired