Bis(1,3,4-thiadiazolo)-1,3,5-triazinium Halides. 2. Intramolecular Ring Transformation and Synthesis of Novel Highly Substituted Guanidines
作者:Kurt Wermann、Martin Walther、Wolfgang Günther、Helmar Görls、Ernst Anders
DOI:10.1021/jo001016a
日期:2001.2.1
ring openings, rearrangements, and ring closure processes is initiated which finally leads via 17 and 18 to novel highlysubstituted guanidines 9, 10, 12, and 13. Pathway b seems to be the result of well-balanced negative-hyperconjugative effects in 14 and/or 17 which control the highly selective opening of a relatively stable central 1,3,5-triazinium ring to yield the crucial intermediate 18. Some