Double Cycloaddition Reaction of Imidazolium Methylides. Intermolecular 1,3-Dipolar and Intramolecular Diels-Alder Cycloaddition Reactions
作者:Otohiko Tsuge、Shuji Kanemasa、Shigeori Takenaka
DOI:10.1246/bcsj.56.2073
日期:1983.7
react with the methylenecyclopropenes with unsaturated substituents at the 4-position in the fashion of double cycloaddition reaction, leading to the novelcagecompounds, which involves an intermorecular 1,3-dipolar cycloaddition reaction and an intramolecular Diels-Alderreaction.
Spirally twisted imidazolium iminyl ylide structures from 1,2-rearrangements in reactions of imidazolium dicyanomethanide 1,3-dipoles with maleic anhydride: new perspectives on the Boekelheide–Fedoruk ring expansions
作者:Richard N. Butler、Helena A. Gavin、Eamon M. Moloney、Patick McArdle、Desmond Cunningham、Luke A. Burke
DOI:10.1016/j.tetlet.2006.06.089
日期:2006.8
The reactions of 1-substituted-imidazolium-3-dicyanomethanides with maleic anhydride gave new ylide products from a Michael reaction and 1,2-rearrangements. These experiments, combined with theoretical calculations, provide an interesting new perspective on the Boekelheide-Fedoruk ring expansions. (c) 2006 Elsevier Ltd. All rights reserved.
10.1002/ejoc.202400163
作者:Kahnert, Sean Ray、Namyslo, Jan C.、Rissanen, Kari、Nieger, Martin、Schmidt, Andreas
DOI:10.1002/ejoc.202400163
日期:——
Imidazolium-ylides are conjugated mesomeric betaines with an exocyclic anionic carbon substituent. These ylides were converted by deprotonation into anionic N-heterocyclic carbenes, which can be formulated with two negative charges on the carbene carbon atom due to their origin. Subsequent reaction with selenium gave anionic selenourea compounds.