An Improved Method for Preparation of Nitrile Oxides from Nitroalkanes for In Situ Dipolar Cycloadditions
作者:Yochai Basel、Alfred Hassner
DOI:10.1055/s-1997-1181
日期:1997.3
A new method has been found for generation of nitrile oxides in situ from nitroalkanes under mild conditions. Thus, reaction of nitroalkanes 1 with di-tert-butyl dicarbonate (2) and 4-dimethyl-aminopyridine (3) as catalyst in the presence of dipolarophiles at room temperature afforded cycloadducts (e.g. 5,6, and 7) in improved yields compared to known methods. Solvent effects were also noted.
HERBICIDALLY AND FUNGICIDALLY ACTIVE 3-HETEROARYL-ISOXAZOLINE-5-CARBOXAMIDES AND 3-HETEROARYL-ISOXAZOLINE-5-THIOAMIDES
申请人:BAYER CROPSCIENCE AG
公开号:US20150223461A1
公开(公告)日:2015-08-13
Herbicidally and fungicidally active 3-heteroaryl-isoxazoline-5-carboxamides and 3-heteroaryl-isoxazoline-5-thioamides
Herbicidally and fungicidally active 3-heteroarylisoxazoline-5-carboxamides and 3-heteroarylisoxazoline-5-thioamides of the formula (I) are described.
In this formula (I), R represents radicals such as hydrogen, halogen and organic radicals such as substituted alkyl. A is a bond or a divalent unit. Y is a chalcogen.
A practical and safe reduction methodology for the conversion of Î2-isoxazolines to 1,3-aminols is developed using polymethylhydrosiloxane-Pd(OH)2/C. In presence of (Boc)2O, the isoxazoline was converted into N-Boc protected 1,3-aminol in a one-pot procedure.