Preparation and properties of some thiouronium fluorenylides and cyclopentadienylides and the attempted preparation of selenouronium and guanidinium fluorenylides
作者:D. Lloyd、R.W. Millar、H. lumbroso、C. liégeois
DOI:10.1016/0040-4020(77)84089-1
日期:1977.1
cyelopentadienylides, prepared by treatment of the corresponding thiouronium salts with non-aqueous base, exist as tautomeric mixtures of the fluorenylide and fluorenylisothiourea, but undergo reactions typical of ylides, e.g. Wittig reactions with aldehydes or nitrosobenzene; a 2,3,4-triphenylcyclopentadienylide gave anomalous products. The ylides also react with acids, alkali, benzyl bromide, and dimethylacetylene
The properties of a number of heteronium tetraphenylcyclopentadienylides with a variety of hetero-atoms are reported, including their UV spectra, basicities, and reactivities towards aldehydes and nitrosobenzene. These properties are very dependent on the identity of the hetero-atoms; with elements of either Group V or Group VI of the periodic table the dipolar and nucleophilic character of the ylides
Construction of polysubstituted pentafulvenes <i>via</i> palladium-catalyzed deacetylation of enones
作者:Ling-Jun Li、Xing Wang、Hui Xu、Hui-Xiong Dai
DOI:10.1039/d2cc06644k
日期:——
Herein, we report an efficient synthetic method for polysubstituted pentafulvenes via palladium-catalyzed deacetylative [2+2+1] annulation of enones with alkynes. Aryl-, alkenyl-, and alkyl-substituted α,β-enones were suitable substrates, affording the pentafulvene products in moderate to good yields. This protocol shows excellent compatibility with sensitive halides, free hydroxyl groups, and heterocycles