Dipotassium Hydrogen Phosphate-Catalyzed Synthesis of Dialkyl 2-(4-Fluoro-Phenoxy)-2-Butendioates From Stabilized Phosphorus Ylides in Solvent-Free Conditions

Four-Component Synthesis of 2-(N,N-Dialkylamino)-2,4,6-Cycloheptatrien-1-One Derivatives from Tropolone, an Isocyanide, a Primary Amine and an Aldehyde via Ugi-Smiles Coupling Reaction

“…[14][15][16][17][18][19][20] As part of our ongoing program to develop efficient and robust methods for the synthesis of heteroatom-containing compounds, [21][22][23][24][25][26] we sought to develop a convenient preparation of a new class of 2-(N,N-dialkylamino)-2,4,6-cycloheptatrien-1-one derivatives 5a-j by a novel four-component condensation reaction of aldehydes 1, primary amines 2, isocyanides 3 and tropolone 4 in fairly good yields (Scheme 1).…”

Synthesis of stabilized phosphorus ylides from electron-poor alcohols and their applications in the preparation of 2,5-dihydrofuran derivatives

“…The proton affinity of these ylides can be used as a molecular guide to assess their utility as synthetic reagents and their function as ligands in coordination and organometallic chemistry [3,4]. In the past we have established a convenient, one-pot method for preparing stabilized phosphorus ylides utilizing an in situ generation of the phosphonium salts [7][8][9][10][11][12][13][14][15][16]. Stabilized phosphorus ylides, versatile intermediates in synthetic organic chemistry can be prepared by the novel reaction of dialkyl acetylenedicarboxylates (DAAD), triphenylphosphine (TPP) and acids such as phenols, imides, amides, enols, oximes and alcohols [7][8][9][10][11][12][13][14][15][16].…”

“…Most of the phosphonium salts are usually made from phosphine and an alkyl halide [1], and they are also obtained by the Michael addition of phosphorus nucleophiles to activated olefins [2]. β-Additions of nucleophiles to the vinyl group of vinylic phosphonium salts leading to the formation of new alkylidenephosphoranes have attracted much attention as a very convenient and synthetically useful method in organic synthesis [7][8][9][10][11][12][13][14][15][16]. Phosphorus ylides are a class of special type of zwitterions, which bear strongly nucleophilic electron rich carbanions.…”

“…The reaction [2] involves an intermediate formed by the 1:1 conjugate addition reaction of the TPP to DAAD, and concomitant protonation of the intermediate by an acid leads to vinyltriphenylphosphonium salts [7][8][9][10][11][12][13][14][15][16]. The salts are unstable intermediates and converted to stabilized phosphorus ylides via a Michael addition reaction [7][8][9][10][11][12][13][14][15][16]. The stabilized phosphorus ylides are able to take part in the intramolecular Wittig reactions [2] but they are not generally able to participate in the intermolecular Wittig reactions [2].…”

“…Stabilized phosphorus ylides, versatile intermediates in synthetic organic chemistry can be prepared by the novel reaction of dialkyl acetylenedicarboxylates (DAAD), triphenylphosphine (TPP) and acids such as phenols, imides, amides, enols, oximes and alcohols [7][8][9][10][11][12][13][14][15][16]. The reaction [2] involves an intermediate formed by the 1:1 conjugate addition reaction of the TPP to DAAD, and concomitant protonation of the intermediate by an acid leads to vinyltriphenylphosphonium salts [7][8][9][10][11][12][13][14][15][16]. The salts are unstable intermediates and converted to stabilized phosphorus ylides via a Michael addition reaction [7][8][9][10][11][12][13][14][15][16].…”