The [2+3] cycloadditionreaction between nitrile oxides 2 and the captodative olefins 1 or the methyl crotonate derivatives 4 is regioselective and leads to the formation of the 5-substituted amino-isoxazole 3 or the 4-substituted methoxycarbonyl-isoxazole 5 derivatives, respectively. All these reactions are greatly accelerated by microwave irradiation without changing their regioselectivity with respect
Cyclopeptide alkaloid model studies. A two-step conversion of 5-aminoisoxazoles to amino acid bis-amides
作者:Bruce H. Lipshutz、Deborah C. Reuter
DOI:10.1016/s0040-4039(00)82266-2
日期:——
Thermolyses of substituted 5-aminoisoxazoles, readily available from common starting materials, lead to azirines in good yields. Subsequent hydration affords -amide derivatives of amino acids.
A one-pot reaction to synthesize functionalized 2H-azirines through visible-light-mediated ring contraction and olefinmetathesis of isoxazoles is described. Hoveyda–Grubbs II catalyst was found to function as a photocatalyst for these transformations, allowing these processes to be carried out in a one-pot manner. This study offers a new entry for the application of Grubbs catalysts as efficient photocatalysts
A Convenient Synthesis of 4-Alkyl-5-aminoisoxazoles
作者:Matthew P. Bourbeau、James T. Rider
DOI:10.1021/ol061260+
日期:2006.8.1
A series of 4-alkyl-5-aminoisoxazoles have been synthesized in high yield by nucleophilic addition of lithiated alkyl nitriles to (alpha)-chlorooximes. The scope and limitations of this reaction were examined by varying the nature of the nitrile and chloride oxime.
Thermolysis of heterocyclic azides. Rearrangement involving acyl migration from carbon to nitrogen