Synthesis of hexahydropyridazine-3-phosphonic acid

The synthesis of hexahydropyridazine-3-phosphonic acid (piperidazine-3-phosphonic acid) was performed via a hetero-Diels-Alder reaction followed by Lewis acid-catalyzed phosphonylation. This two-step procedure was improved to a one-pot reaction.     

Synthesis of 1,3-diarylsubstituted indazoles utilizing a Suzuki cross-coupling/deprotection/N-arylation sequence

Herein we report a general synthesis of 1,3-diarylsubstituted indazoles utilizing a two-step Suzuki cross-coupling/deprotection/N-arylation sequence. This procedure proceeds in excellent overall yield starting from the 3-iodo-N-Boc indazole derivative allowing for rapid access to these compounds.     

Straightforward synthesis of orthogonally protected piperidin-3-ylmethanamine and piperidin-4-ylmethanamine derivatives

The 1,3- and 1,4-disubstituted piperidines are important building blocks in medicinal chemistry and drug discovery. We present the synthesis of orthogonally protected piperidin-3-ylmethanamine and piperidin-4-ylmethanamine derivatives from commercially available nipecotamide, isonipecotamide, nipecotic acid and isonipecotic acid. This is a straightforward two-step procedure that gives high overall yields. Purification of the intermediates using this procedure is not necessary, and the final compounds are purified by simple flash column chromatography.     

Tuning morphology and conductivity in two-step synthesis of zinc-cobalt oxide and sulfide hybrid nanoclusters as highly-performed electrodes for hybrid supercapacitors

Journal of Solid State Electrochemistry - We reported a facile two-step hydrothermal procedure to prepare zinc-cobalt oxide and sulfide hybrid nanoclusters (ZCOSH NCs), initialized by the synthesis...     

A general synthesis of N-hydroxyindoles

A general method for the formation of N-hydroxyindoles is demonstrated through a lead-promoted intramolecular reductive cyclization of o-nitrobenzyl ketones and aldehydes under transfer hydrogenation conditions. The N-hydroxyindoles are isolated in high purity and excellent yield (>90%) in an operationally simple procedure. This new method is exemplified by a two-step synthesis of the naturally occurring 1-methoxyindole-3-carboxaldehyde, which is pivotal in many alkaloid total syntheses.     

An efficient chemoenzymatic route to dihydroxyacetone phosphate from glycidol for the in situ aldolase-mediated synthesis of monosaccharides

We report a new two-step procedure that uses inexpensive rac-glycidol to obtain valuable dihydroxyacetone phosphate (DHAP), a building block for the synthesis of monosaccharide analogues.     

Regiocontrolled synthesis of carbocycle-fused indoles via arylation of silyl enol ethers with o-nitrophenylphenyliodonium fluoride

[formula: see text] A new, regiocontrolled synthesis of carbocycle-fused indoles has been developed. The two-step procedure involves first the regiospecific arylation of silyl enol ethers with o-nitrophenylphenyliodonium fluoride (1). Reduction of the nitro group on the aromatic ring with TiCl3 followed by spontaneous condensation of the aniline with the ketone then affords the indole products.     

Hammet Constants Effects in Microwave Cascade Etherification-Cyclization-Krapcho Reaction to Access [2,3]-Dihydrobenzofuran-3-ones from Salicylic Derivatives

Two methods were evaluated for the synthesis of substituted [2,3]-dihydro-2-methyl-benzofuran-3-ones from corresponding salicylate esters under microwave irradiation. A two-step sequence via ether intermediates was convenient for various substituted salicylate derivatives, while the second strategy involving a one-pot procedure was efficient for electron-donating substituted salicylates. Results allowed correlation of the Hammett constants effects in the intramolecular cyclization of O-ethoxycarbonyl ether of salicylic esters.     

Total synthesis of leustroducsin B

A convergent total synthesis of leustroducsin B (1), which is known to exhibit a variety of biological activities, was successfully carried out. Notable features of our synthesis include construction of the C8 stereocenter by lipase-mediated desymmetrization of meso-diol 4 (90.2% ee) and preparation of the C9-C11 anti-diol moiety by the addition of alkynylzinc reagent 20 to the aldehyde 19. Furthermore, a new diol protecting group, p-silyloxybenzylidene, was developed for the deprotection from densely functionalized substrates under weakly acidic conditions. The protecting group was easily removed in a two-step procedure ((HF)3.Et3N; AcOH-THF-H2O).     

One-pot enzymatic desymmetrization and Ugi MCR

A new approach to the synthesis of chiral peptidomimetics is reported. It combines an enzymatic desymmetrization of 3-phenylglutaric anhydrides with a subsequent Ugi multi-component reaction in a one-pot, two-step procedure. NMR and CD spectroscopy was used to assign the configurations of obtained products. Our synthetic method is very efficient and it can easily be extended to other types of multi-component reactions and can be used for the preparation of chiral peptidomimetic libraries.     

A single-enzyme, two-step, one-pot synthesis of N-substituted imidazole derivatives containing a glucose branch via combined acylation/Michael addition reaction

Combined regioselective acylation/Michael addition reaction catalyzed by alkaline protease from Bacillus subtilis in anhydrous pyridine for synthesis of N-substituted imidazole derivatives containing a glucose branch via a novel single-enzyme, two-step, one-pot procedure is reported.     

A convenient one-pot synthesis of ethylene blue

We have developed an efficient one-pot, two-step preparation of ethylene blue by eliminating aqueous work-ups and cumbersome purification techniques. Our procedure generates ethylene blue in good overall yields of 45-56% with approximately 95% purity, which is uncommon for the synthesis of a phenothiazinium salt. Due to its unique properties, ethylene blue has great potential for a broad range of biological applications and, as a result, an efficient procedure for the synthesis of ethylene blue is critical.     

Rapid Syntheses of Hexa and Heptahelicene

A two-step synthesis of hexahelicene (scheme 1; 53% over-all yield), a three-step synthesis of hexaheliene (scheme 2; 33% over-all yield), and a two-step synthesis of heptahelicene (scheme 3; 14% over-all yield) are described.     

Synthesis,characterization, and curing of hyperbranched allyl ether–maleate functional ester resins

A model two-step synthesis of a saturated hyperbranched hydroxyl-terminated ester has been developed to show a synthesis route. Three different series of hyperbranched esters with different terminations have been synthesized to relate some of their properties to their structures. This route has then been used to synthesize three different allyl ethermaleate functional hyperbranched ester resins in a two-step procedure. The resins have been characterized with respect to rheology, structure, and properties, and the differences are discussed. The allyl ether-maleate functional resins have also been studied with respect to curing performance and final film properties. © 1993 John Wiley & Sons, Inc.     

Synthesis of tert-butyl peresters from aldehydes by Bu4NI-catalyzed metal-free oxidation and its combination with the Kharasch-Sosnovsky reaction

A new tert-butyl peresters synthesis directly from aldehydes and TBHP was developed via Bu(4)NI-catalyzed aldehyde C-H oxidation. Mechanistic studies suggest that the protocol proceeds via a radical process. Combining the method with the Kharasch-Sosnovsky reaction offers a practical approach for the synthesis of allylic esters from simple aldehydes and alkenes via a two-step one-pot procedure.     

Short and efficient diastereoselective synthesis of pyrrolidinone-containing dipeptide analogues

The pyrrolidine-2,4-diones have been identified as a convenient starting point for the synthesis of peptide analogues. Herein we describe an optimized two-step reductive amination procedure, which provides a small library of pyrrolidinone-containing dipeptide analogues in high yield and excellent diastereoselectivity.     

Reductive rearrangement of 2-aroyl-2,3-dihydrobenzofurans into 2-hydroxydihydrochalcones and flav-2-enes

Chemistry of Heterocyclic Compounds - A two-step procedure was proposed for the synthesis of 2-aryl- and 2,4-diaryl-substituted 4H-chromenes by the formal [4+1] cycloaddition reaction of o-quinone...     

A rapid and efficient microwave-assisted synthesis of hydantoins and thiohydantoins

The present paper describes studies on the synthesis of the antiepileptic drug phenytoin, and of structurally related derivatives. First, the influence of the solvent has been investigated in the microwave-assisted synthesis of the drug, resulting in a yield improvement and a cleaner reaction. Second, a two-step reaction is described to synthesize selectively and in high yields phenytoin. The first step consists in microwave activation of the reaction of benzil with thiourea, the second step includes the conversion of the resulting 2-thiohydantoin to phenytoin using hydrogen peroxide. Moreover, microwave activation is a very convenient method for the synthesis of 3-alkylated phenytoin derivatives, resulting in a much more selective method than the previously reported procedure using alkylating agents.     

Synthesis and application of carbohydrate-derived morpholine amino acids

The synthesis of series of diversely functionalized epsilon-morpholine amino acids (MAAs, 5a-h) starting from an epsilon-sugar amino acid and following a two-step oxidative glycol cleavage/reductive amination strategy, is described. In an alternative synthetic scheme, diastereoisomerically pure delta-MAAs (12a,b) were obtained. Oligopeptides containing MAAs were prepared either by direct incorporation of a MAA building block or by subjecting a fully assembled SAA-containing peptide to the two-step glycol cleavage/reductive amination procedure.     

Microwave-assisted synthesis of 4-quinolylhydrazines followed by nickel boride reduction: a convenient approach to 4-aminoquinolines and derivatives

Nickel(II) chloride/sodium borohydride combination was employed for the reduction of 4-hydrazinoquinoline derivatives to the corresponding anilines. This reductive protocol was efficiently applied for the reductive cleavage of monosubstituted hydrazines. We described herein the microwave-assisted synthesis of 4-hydrazinoquinolines, which furnished a high yielding and rapid two-step procedure for the synthesis, under mild conditions, of 4-aminoquinolines as antimalarial precursors.