如13 C NMR数据所示,炔基取代的吡嗪在二氯甲烷中用四氟硼酸三乙基氧鎓进行季铵化仅在N-4处产生3-炔基-1-乙基吡嗪鎓盐。同样的吡嗪与三氟乙酸的质子化也发生在N-4处。季吡嗪鎓盐以及质子化的吡嗪在比相应的中性吡嗪温和得多的条件下进行分子内Diels-Alder反应。反应产物分别为[ ]-退火的季吡啶鎓盐和[ ]-退火的质子化吡啶鎓阳离子。
Cobalt-Mediated [2+2+2] Cycloaddition versus CH and NH Activation of Pyridones and Pyrazinones with Alkynes: An Experimental Study
作者:Corinne Aubert、Patrick Betschmann、Michael J. Eichberg、Vincent Gandon、Thilo J. Heckrodt、Jürg Lehmann、Max Malacria、Birgit Masjost、Elisa Paredes、K. Peter C. Vollhardt、Glenn D. Whitener
DOI:10.1002/chem.200601823
日期:2007.9.7
thene) has been investigated. Depending on the nature of the substrates, [2+2+2]- or [2+2] cycloaddition, C-H, or N-H activation may occur. In the case of pyridones, the first three predominated with N-protected derivatives, whereas substrates containing N-H bonds followed an N-H activation pathway. The [2+2+2] cycloaddition of an N-butynylisoquinolone was applied successfully to the total synthesis
GEURTSEN, BART;DE, BIE DICK A.;VAN, DER PLAS HENK C., TETRAHEDRON, 45,(1989) N0, C. 6519-6530
作者:GEURTSEN, BART、DE, BIE DICK A.、VAN, DER PLAS HENK C.
DOI:——
日期:——
DE, BIE D. A.;OSTROWICZ, A.;GEURTSEN, G.;VAN, DER PLAS H. C., TETRAHEDRON, 44,(1988) N 10, 2977-2983
作者:DE, BIE D. A.、OSTROWICZ, A.、GEURTSEN, G.、VAN, DER PLAS H. C.
DOI:——
日期:——
Novel ring transformations of pyrazines by intramolecular diels-alder reactions
作者:D.A. De Bie、A. Ostrowica、G. Geurtsen、H.C. Van Der Plas
DOI:10.1016/s0040-4020(88)90036-1
日期:1988.1
Intramolecular Diels-Alder reactions of quaternary pyrazinium salts and protonated pyrazinium cations. Synthesis of annelated pyridinium salts and annelated pyridines.
作者:Bart Geurtsen、Dick A. de Bie、Henk C. van der Plas
DOI:10.1016/s0040-4020(01)89528-4
日期:1989.1
quaternary pyrazinium salts as well as the protonated pyrazines undergo an intramolecular Diels-Alder reaction under considerably milder conditions than the corresponding neutral pyrazines. The products of the reactions were []-annelated quaternary pyridinium salts and []-annelated protonated pyridiniumcations, respectively.
如13 C NMR数据所示,炔基取代的吡嗪在二氯甲烷中用四氟硼酸三乙基氧鎓进行季铵化仅在N-4处产生3-炔基-1-乙基吡嗪鎓盐。同样的吡嗪与三氟乙酸的质子化也发生在N-4处。季吡嗪鎓盐以及质子化的吡嗪在比相应的中性吡嗪温和得多的条件下进行分子内Diels-Alder反应。反应产物分别为[ ]-退火的季吡啶鎓盐和[ ]-退火的质子化吡啶鎓阳离子。