Synthesis 2001, No. 11, 28 08 2001. Article Identifier: 1437-210X,E;2001,0,11,1742,1746,ftx,en;C03701SS.pdf. © Georg Thieme Verlag Stuttgart · New York ISSN 0039-7881 Abstract: The catalytic asymmetric alkylation under phase-transfer conditions of various substrates (enones, -fluoro ketones, glycineimines) promoted by chiral quaternary ammonium salts derived from cinchona alkaloids is described...

Some 2-iminothiazolidin-4-ones have been synthesized by the reaction of dialkyl acetylenedicarboxylates with thiosemicarbazones. The reaction was performed in the presence of 10 mol% of triphenylphosphine and tetrabutylammonium bromide as a phase transfer catalyst in water as a green solvent. All the synthesized compounds were characterized by their physical and spectral data.

In this study, a one-pot and efficient method is reported for the synthesis of symmetrical disulfides from alkyl halides in the present of sulfur and 1-butyl-3-methylimidazolium hydroxide as a basic reagent and phase transfer catalyst. The reaction proceeded very fast and afforded the desired products in moderate to excellent isolated yields.  

Efficient catalytic asymmetric synthesis of 1,1-disubstituted tetrahydro-β-carbolines has been achieved via asymmetric alkylation of 1-cyanotetrahydro-β-carbolines using a binaphthyl-modified N-spiro-type chiral phase-transfer catalyst. This is a valuable example of hitherto difficult highly enantioselective alkylations at α-carbon of the cyano group under phase-transfer conditions.

Palladium nanoparticles have been electrochemically supported on zirconium oxide nanostructured powders and all the nanomaterials have been characterized by several analytical techniques. The Pd/ZrO(2) nanocatalyst is demonstrated to be a very efficient catalyst in Heck, Ullmann, and Suzuki reactions of aryl halides in water. The catalyst efficiency is attributed to the stabilization of Pd nano...

A group effort: Reported is the title reaction using a polycomponent catalytic system involving commercially available Selectfluor, a putative radical precursor N-hydroxyphthalimide, an anionic phase-transfer catalyst (KB(C(6)F(5))(4)), and a copper(I) bis(imine). The catalyst system formed leads to monofluorinated compounds selectively (see example) without the necessity for an excess of the a...

Highly enantioselective phase-transfer alkylation of 3-substituted-2-oxindoles with activated bromomethanes is disclosed with a broad substrate scope by using bicyclic guanidinium as a catalyst and a Lewis acid as the co-catalyst. The alkylation adducts are versatile intermediates to accomplish the syntheses of pyrroloindolines and furoindolines.

A temperature-controlled phase-transfer catalyst-tungsten acid, which in combination with a robust heterogeneous catalyst Ru/C shows a high activity and exceptional reusability for the one-pot conversion of cellulose to ethylene glycol. This binary system can be reused more than 20 times with ethylene glycol yield over 50%.