Preparation and pyrolysis of 1-(pyrazol-5-yl)-1,2,3-triazoles and related compounds 1
作者:David Clarke、Richard W. Mares、Hamish McNab
DOI:10.1039/a700421d
日期:——
1-(Pyrazol-5-yl)-1,2,3-triazoles 8a, 9a and 10 are prepared by
cycloaddition of 5-azidopyrazoles with methyl prop-2-ynoate. The
regiochemistry of the process is confirmed by synthesis of 9a using an
authentic route from ethyl 2-formyl-2-diazoacetate 13. Flash vacuum
pyrolysis of 8a, 9a and 10 gives
5-methoxypyrazolo[1,5-a]pyrimidin-7-ones 16–18 by a
mechanism involving an unexpected oxoketenimine–imidoyl ketene
rearrangement as the key step. The mechanism is supported by a
13C labelling experiment. A general route to
pyrazolo[1,5-a]pyrimidin-7-ones from pyrazolylaminomethylene
Meldrum's acid derivatives (e.g. 30–32) is also
reported.
Nitrogen‐rich quantumdots (N‐dots) were serendipitously synthesized in methanol or aqueous solution at a reaction temperature as low as 50 °C. These N‐dots have a small size (less than 10 nm) and contain a high percentage of the element nitrogen, and are thus a new member of quantum‐dot family. These N‐dots show unique and distinct photoluminescenceproperties with an increasing percentage of nitrogen
ALCALDE E.; CLARAMUNT R. M., TETRAHEDRON LETT. <TELE-AY>, 1975, NO 18, 1523-1524
作者:ALCALDE E.、 CLARAMUNT R. M.
DOI:——
日期:——
GRANADOS R.; RULL M.; VILARRASA J., J. HETEROCYCL. CHEM., 1976, 13, NO 2, 281-284
作者:GRANADOS R.、 RULL M.、 VILARRASA J.
DOI:——
日期:——
Assembly of the Bis(imidazolyl)propene Core of Nagelamides C and S by Double Grignard Reaction
作者:Nicolas Jacobi、Thomas Lindel
DOI:10.1002/ejoc.201000625
日期:——
1-bis(imidazolyl)-propenes were assembled in a facile manner by double Grignard reaction of metalated imidazoles with saturated esters, followed by dehydration. The presence of nitrile functions or acryl esters in the electrophile component leads to competing reactions, whereas propargyl esters are tolerated. Introduction of 2-amino groups was possible via the corresponding dimethylsulfamoyl-protected