The synthesis of the macrolactone core of (+)-neopeltolide has been achieved. The key synthetic strategy involves the highly diastereoselective synthesis of the 2,6-cis-disubstituted tetrahydropyran ring by a transannular cyclization of δ-hydroxy alkene using mercuric trifluoroacetate. Two of the six stereocenters C-5 and C-11 were realized from L-malic acid, while the remaining stereocenters C...

An efficient and convenient procedure for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and thiones by condensation of 1,3-dicarbonyl compounds, Aromatic and aliphatic aldehydes, and urea or thiourea in the presence of catalytic amount of Brønsted acidic ionic liquid 3-methyl-1-sulfonic acid imidazolium chloride {[Msim]Cl} under thermal solvent-free conditions reacted easily to afford the co...

Nano-silica-bonded 3-n-propyl-1-sulfonic acid imidazolium chloride (nano-SB-[PSIM]Cl) was applied as a highly efficient, general and heterogeneous catalyst for one pot multi-component reaction of 2-naphthol, arylaldehydes, and thioacetamide leading to 1-thioamidolakyl-2-naphthols. All reactions proceeded with excellent yields in short times under solvent-free conditions. Our protocol was superi...

Complex [Au{4-C(6)F(4)(4-C(6)BrF(4))}(tht)] reacts with diphosphines (L-L) such as bis(diphenylphosphino)methane (dppm) or 1,2-bis(diphenylphosphino)benzene (dppb) in a 2 : 1 molar ratio in dichloromethane, leading to neutral products of stoichiometry [(Au{4-C(6)F(4)(4-C(6)BrF(4))})(2)(μ-L-L)] (L-L = dppm (1), dppb (2)). In the crystal structure of complex 2 short Au···Au interactions of 2.9367...

Molecular oxygen can replace sacrificial olefins as the hydrogen acceptor in the palladium trifluoroacetate catalyzed dehydrogenation of cyclohexene and related cyclic olefins into aromatics. One of the major drawbacks of the homogeneous system is the tendency of the palladium trifluoroacetate to precipitate as palladium(0) at elevated temperatures. The use of better ligands affords catalysts t...

A novel stilbene disulfonate, 4-trimethylammonium-4'-isothiocyanostilbene-2,2'-disulfonic acid (TIDS), has been chemically synthesized, and the interaction of this probe with human erythrocyte anion exchanger (AE1) was characterized. Covalent labeling of intact erythrocytes by [N(+)((14)CH(3))(3)]TIDS revealed that specific modification of AE1 was achieved only after removal of other ligand bin...

Friedel–Crafts synthesis of triarylmethanes over 3-methyl-1-sulfonic acid imidazolium tetrachloroaluminate under green conditions:In this work, Friedel–Crafts (FC) alkylation of various arenes with aromatic aldehydes catalyzed by 3-methyl-1-sulfonic acid imidazoliumtetrachloroaluminate {[Msim]AlCl4}, as a green catalyst, to prepare triarylmethanes (TAMs) has been carried out. Some aromatic alde...

Abstract: A thermodynamic consistency test developed for high pressure binary vapor-liquid mixtures is applied to mixtures containing a supercritical solvent and an ionic liquid. Several authors have reported vapor-liquid equilibrium data on the binary systems supercritical CO2 + 1-butyl-3-methyl imidazolium hexafluorophosphate {[bmim][PF6]}, supercritical CO2 + 1-butyl-3-methyl imidazolium nit...