Reactions of Sulfonium Phenacylide With Active Methylene Compounds

Abstract

The reaction of dimethylsulfonium phenacylide 1 with malononitrile gave C-phenacylated compound. The reaction of 1 with acetylacetone or ethyl acetoacetate led to dihydrofuran derivatives via O-phenacylation followed by cyclization.

Reactions of Diphenyl(phenylethynyl)selenonium Salts with Active Methylene Compounds and Amides: First Isolation of Oxyselenuranes [10-Se-4(C3O)] as a Reaction Intermediate

“…The reaction of 1a with 2,4-pentanedione 5a and t -BuOK in THF gave a furan derivative 6a (40%) and diphenyl selenide 7a (62%). The yield of this reaction was much improved by refluxing the reaction mixture.…”

The Chemistry of α-Haloketones and Their Utility in Heterocyclic Synthesis

“…The reaction of α-bromoacetophenones with malononitrile ( 250 ) affords 2-amino-3-cyanofuran derivatives 251 . This reaction, aimed at heterocyclic synthesis of furans and their fused systems, was first reported by Gewald and subsequently explored by other groups ( Scheme 74 ) [ 490 , 491 , 492 , 493 , 494 , 495 , 496 , 497 , 498 , 499 , 500 , 501 ].…”

Cross-coupling of dissimilar ketone enolates via enolonium species to afford non-symmetrical 1,4-diketones

“…This is due to the facile conversion of 1,4-dicarbonyl compounds into five-membered heterocycles such as thiophenes, furans, and pyrroles. Consequently, numerous multistep approaches to unsymmetrical 1,4-dicarbonyl compounds involving, e.g., S N 2-type displacements [ 1 ] or highly functionalized substrates such as β-ketoesters [ 2 – 3 ] or β-ketosulfones [ 4 ] have been developed. Recently, Loh reported the palladium-catalyzed coupling of an acid chloride with premade isolable indium homoenolates (In(CH 2 CHRC=OR') 2 ), 1.2 equiv relative to the acid chloride) to give the corresponding 1,4-diketones [ 5 ].…”