Regioselective Synthesis of Silylated Pyrazolines and Indazolines by Reaction of Pyrazolium and Indazolium Salts with Silyllithium Reagents
作者:Ana M. González-Nogal、Mariola Calle、Luis A. Calvo、Purificación Cuadrado、Alfonso González-Ortega
DOI:10.1002/ejoc.200500438
日期:2005.11
Pyrazoliumsalts react with dimethylphenylsilyl- and tert-butyldiphenylsilyllithium to give, in general, only one of the two possible 5-silyl-3-pyrazolines. On the other hand, indazolium and isoindazolium salts lead to 3-silylindazolines and occasionally to compounds resulting from the opening or expansion of the heterocyclic ring. All of these compounds are interesting synthons in organic chemistry
Reactions of pyrazolium salts with silyllithium reagents. Regioselective synthesis of 5-silylated 3-pyrazolines
作者:Purificación Cuadrado、Ana M. González-Nogal
DOI:10.1016/s0040-4039(97)10825-5
日期:1998.3
1,3,5-trisubstituted-2-methylpyrazolium iodides react with dimethylphenylsilyl- and tert-butyldiphenylsilyllithium leading, in general, to one of the corresponding 5-silyl-3-pyrazolines. The silyl group is easily substituted by electrophiles to give 5-functionalized 3-pyrazolines.Moreover, 5-silyl-3-pyrazolines undergo thermic ring opening with silicon-rearrangement affording α-silylated β-diimines
Charge distribution and conformational stability effects of organic structure-directing agents on zeolite synthesis
作者:Donghui Jo、Suk Bong Hong
DOI:10.1039/c7cc08818c
日期:——
While the use of the so-called organic structure-directing agents (OSDAs) is no stranger to zeolite synthesis at all, the effects of their charge distribution and conformationalstability on the phase selectivity of the crystallization remain elusive. To systematically investigate these effects, we have prepared a series of imidazolium and pyrazolium derivatives with the same geometric shape but different