Intramolecular [4 + 2] Cycloaddition Reaction of Six- and Seven-Membered Cyclic <i>N</i>-Allyl-<i>C</i>-arylethynyl Iminium Salts
作者:Hans-Georg Herz、Jürgen Schatz、Gerhard Maas
DOI:10.1021/jo015546y
日期:2001.5.1
5,6,7-tetrahydro-3H-azepinium triflates 1g,h undergo a thermal isomerization reaction leading to derivatives of [a,f]-annulated isoindolium salts 2 in good yields. Similarly, N-allyl-2-phenylethynyl-pyridinium triflate 4 is transformed into the condensed pyridinium salt 5. An intramolecular [4 + 2] cycloadditionreaction, in which the (het)arylethynyl moiety acts as the 4pi component, is considered