Showing papers in "Synthetic Communications in 1992"

TL;DR: The syntheses of methoxypoly(ethyleneglycol) derivatives, functionalized either as hydrazides for the selective attachment of meth oxypoly (ethylenegialcol) to carbohydrate domains of glycoproteins, or as iodoacetamides and maleimide for the modification of free sulfhydryl groups, are described.

TL;DR: In this paper, an efficient one-pot synthesis of anilinobenzylphosphonates using BF3OEt2 as a catalytic catalyst was achieved from aniline, benzaldehyde, and dialkylphosphite.

TL;DR: In this paper, the reduction of nitro aromatics containing other susceptible groups is reinvestigated to provide a viable economic route from the point of view of quantitative transformation, reduced reaction times and simple work up using iron powder and ammonium chloride solution in neutral medium.

TL;DR: In this paper, 2-Arylsubstituted benzimidazoles, quinoxalines, in 3,5-posi-tion substituted 2,6-dimethylpyridines, and 1,4-bis(alkylamino)-9,10-anthracenediones are easily prepared under mild conditions by means of benzofuroxan as oxidant.

TL;DR: In this article, the Moody azide/Schollkopf chiral auxiliary protocol has been used for the synthesis of optically active ring-A methoxylated indole alkaloids.

TL;DR: In this article, a dye 3 with sodium methoxide, morpholine, or diphenylphosphine gives the respective substituted derivatives 4, 5 and 6 in high yields.

TL;DR: In this paper, a simple and quick synthesis of tetrapyrrolic macrocycle in dry media conditions, under microwave irradiation, was reported, with very simplified treatment and purification.

TL;DR: In this article, an efficient synthetic procedure for the preparation of versatile functionally substituted arylphosphines from commercially available starting materials is reported together with alternative synthetic routes for (carboxyphenyl)diphenyl phos-phines.

TL;DR: Iodination of aromatic amines with iodine / silver sulfate at room temperature gives iodo-products in good (46-96%) yield as discussed by the authors, which is the state-of-the-art.

TL;DR: Fluorination of vinyl stannanes takes place in moderate yields with xenon difluoride in the presence of silver hexafluorophosphate in this paper.

TL;DR: Benzyltriethylammonium tetrathiomolybdate has been found to be a superior reagent for the conversion of alkyl halides to the corresponding disulfides in chloroform at room temperature.

TL;DR: In this article, the Mitsunobu reaction of diethyl 1-hydroxyalkylphosphonates with hydrazoic acid was used to obtain the title compounds.

TL;DR: Rephosgenation of N-carboxyanhydrides of γ-benzyl and y-methyl L-glutamates, vs multiple recrystallizations, is a very efficient method for obtaining very high MW (0.98-1.5 × 106 Daltons) polymers can be derived.

TL;DR: Secondary alcohols are rapidly oxidized to ketones by a solution of trichloroisocyanuric acid in acetone as discussed by the authors, which is known as TOCA.

TL;DR: In this article, a simple and extremely versatile procedure for the conversion of arylamines into the corresponding arylfluorides is described. But the method is applicable only to arylines bearing carboxyl and hydroxyl substituents which give poor yields under Balz-Schneider conditions.

TL;DR: In this article, the reduction of prochiral ketones with borane in the presence of homochiral amino alcohols 1-3 as enantioselective catalysts afforded the corresponding secondary alcohols in moderate to high (69 to 99 %) optical yields.

TL;DR: Arylthiols, aralkylthiol and alkane thiols can be readily alkylated by alkyl/aralkyl halides in presence of K2CO3DMF to yield unsymmetrical sulphides in nearly quantitative yields as discussed by the authors.

TL;DR: In this paper, commercial malic acid is used for the synthesis of substituted 1,2 and 1,3 optically active diols, which is used to synthesize substituted 1.

TL;DR: Palladium-catalyzed coupling of 1-(phenylsulfonyl)indol-3-yl trifluoromethanesulfonate (triflate) with terminal alkenes and alkynes gives 3-vinyl (2) and 3-alkynylindoles in 45-93% yields as discussed by the authors.

TL;DR: In this article, a new approach for the synthesis of α-methylene-γ-butyrolactones from the reaction of αbromomethyl acrylic acid (or ester), powdered tin and carbonyl compounds in one pot with excellent to good yields is presented.

TL;DR: In this article, a simple method for chemically differentiating primary and secondary amines is described in which the primary amine is condensed with benzaldehyde to form an imine leaving the secondary amine available to be protected with BOC.

TL;DR: In this paper, the homochiral Rh(II) carboxylates, Na4Rh2(CO3)4, are readily prepared in good yield by reaction of carboxylic acids with the Rh(2) carbonato species.

TL;DR: In this paper, 3-Bromopropiolic esters are efficiently prepared by reaction of corresponding propiolic isters with N-bromosuccinimide in acetone and silver nitrate as catalyst.

TL;DR: Sulfuric acid adsorbed on silica gel is an efficient catalyst for the tetra-hydropyranylation of alcohols and phenols as discussed by the authors, which takes 1 to 10 minutes to be completed and nearly quantitative yields are obtained.

TL;DR: Synthesis of six-membered N-heterocycles from 2′-NHR-chalcones, 2′ -nhr-chalcone dibromides and 2′ nhr-α-azidochalcones are described and discussed in this article.

TL;DR: In this paper, 2H-Chromeno[2,3-d]-pyrimidine-2,4(3H)-diones were prepared directly from barbituric acid and salicylaldehydes or by thermal cyclization of the condensation product of 6-bromopiperonal.

TL;DR: In this article, an understanding of the mechanism by which racemization occurs in the Hantzsch reaction preparation of 2-(1-aminoalkyl)thiazoles has enabled the development of a methodology to prevent raceemization.

TL;DR: In this paper, a convenient method for the preparation of Ph2PC6H4COOH-2 (2) and Ph 2PC 6H4CHO-2(5) was described.

TL;DR: Highly selective ring bromination of alkyl-substituted aromatic hydrocarbons has been achieved using molecular bromine adsorbed on the surface of alumina without any solvent.

TL;DR: In this article, the oxidation procedure plus a simple preparation of oiodosylbenzoic acid are described, and a simple procedure for the extraction of ODEs is described.