Solid-phase synthesis of polyfunctional polylysine dendrons using aldehyde linkers

A straightforward method for the solid-phase synthesis of C-terminally modified polylysine dendrons has been developed by applying bisalkoxybenzaldehyde and trisalkoxybenzaldehyde linkers. The method has been used for the synthesis of polylysine dendrons with a variety of C-terminal ‘tail groups’ such as alkyl, propargyl, and dansyl to give dendrons in high crude purity. Furthermore, the method was successful for the synthesis of dendrons with multiple N-terminal pentapeptide groups together with C-terminal alkyl and propargyl tail groups. Finally, the method was shown to be well-suited for automated synthesis.     

A clean and expedient synthesis of spirooxindoles in aqueous media catalyzed over nanocrystalline MgO

An efficient and eco-friendly method for the synthesis of spirooxindoles with fused tetrahydrochromenes has been demonstrated using basic nanocrystalline MgO catalyst in aqueous condition. The method has been applied for the synthesis of a range of compounds with variable functionalities in excellent yield and selectivity.     

A competent pot and atom-efficient synthesis of Betti bases over nanocrystalline MgO involving a modified Mannich type reaction

A simple, efficient, and eco-friendly method for the synthesis of 1-(α-aminoalkyl) naphthols, the Betti bases, has been carried out over a basic nanocrystalline MgO catalyst in aqueous condition. The method has been applied for the synthesis of a range of compounds with variable functionalities in excellent yield and selectivity.     

New method for the direct electrophilic amination of aromatic compounds and its use in the annelation of the pyrimidine ring

A method has been developed for the synthesis of aromatic amines by the amination of the corresponding aromatic compounds using sodium azide in PPA. A method for the synthesis of quinazolines and benzo[h]quinazolines using this reaction and the subsequent reaction of the intermediates with 1,3,5-triazines has been developed.     

One‐Pot Synthesis of Hydrophobically Modified Iminosugar C‐Alkynylglycosides: Facile Synthesis of Polyhydroxy Tetrahydroindolizines

A mild and efficient one‐pot method has been developed for the stereoselective synthesis of structurally diverse novel iminosugar C‐alkynylglycosides. The generality of this methodology has been demonstrated with a wide variety of amines and copper acetylides. This one‐pot method has been exploited in the synthesis of new class of DNA cross‐linking agents, polyhydroxy 1‐vinyl‐tetrahydroindolizine derivatives.     

Synthesis of substituted benzoxazoles by the iron(Ⅲ)-catalyzed aerobic oxidation process

The FeCl3-catalyzed aerobic oxidation process for the synthesis of benzoxazoles,benzothiazole and benzimidazole has been discovered.This method has proved to be effective to a wide range of substrates,and it has been applied for the synthesis of JTP-426467.     

Sulfated tungstate: a green catalyst for Strecker reaction

A straightforward, mild, efficient, and general method has been developed for the synthesis of α-aminonitriles via Strecker reaction starting from aldehydes or ketones, amines, and trimethylsilyl cyanide in the presence of sulfated tungstate as a heterogeneous mild solid acid catalyst at room temperature and solvent free condition. The developed method has been successfully applied for the synthesis of a wide range of α-aminonitriles with variable functionality.     

Synthesis of photochromic diarylethenes using a microflow system

An effective method for the synthesis of photochromic diarylethenes based on microflow systems has been developed, and the synthesis of unsymmetrical diarylethenes which is difficult to achieve using conventional macro batch systems, has been accomplished.     

Light-directed maskless synthesis of peptide arrays using photolabile amino acid monomers

Novel photolabile amino acid monomers for photolithographic solid-phase peptide synthesis has been developed and a method for the maskless synthesis of individually addressable peptide microarrays using new building blocks has been described; these peptide microarrays are suitable for repetitive epitope-binding assays.     

Regiospecific synthesis of 3-(2,6-dihydroxyphenyl)phthalides: application to the synthesis of isopestacin and cryphonectric acid

DBU catalyzed condensation of phthalaldehydic acids and 1,3-diketones has been developed to be a general method for the synthesis of 3-substituted phthalides. This method, in combination with mercuric acetate mediated oxidative aromatization has been utilized for the regiospecific synthesis of isopestacin (9) and cryphonectric acid (10).     

Palladium(0)-catalysed cross-coupling of 2-trimethylsilylpyridine with aryl halides

A general method for the Hiyama coupling reaction between aryl halides and 2-trimethylsilylpyridine has been developed. These conditions have been successfully applied to the synthesis of bis-heteroaryl systems, a key disconnection for the pharmaceutical industry in the synthesis of drug-like molecules.     

Enzyme-catalyzed peptide synthesis in ice

A new method for increasing product yield in kinetically controlled enzymatic peptide synthesis catalyzed by serine and cysteine proteases is proposed - freezing the reaction mixture. The use of the method in preparative synthesis has been demonstrated.     

A new RNA synthetic method with a 2'-O-(2-cyanoethoxymethyl) protecting group

A novel method for the synthesis of RNA oligomers with 2-cyanoethoxymethyl (CEM) as the 2'-hydroxyl protecting group has been developed. The new method allows the synthesis of oligoribonucleotides with an efficiency and final purity comparable to that obtained in DNA synthesis. [structure: see text]     

Synthesis of the EF-ring segment of ciguatoxin CTX1B based on novel regioselective reduction of unsaturated cyanohydrins and ring-closing olefin metathesis

Aiming at a convergent total synthesis of ciguatoxin CTX1B, its EF-ring segment has been synthesized. During the synthesis, a novel method for the construction of branched ethers, based on regioselective reduction of γ-alkoxy β,γ-unsaturated α-silyloxy nitriles with borontrifluoride etherate and trialkyl silane or tributyltin hydride, has been developed. Combination use of the method and ring-closing olefin metathesis successfully provided medium-sized cyclic ethers. Efficient site-selective reduction of vinyl epoxides into homoallyl alcohols has also been developed.     

Base- and ligand-free room-temperature synthesis of N-fused heteroaromatic compounds via the transition metal-catalyzed cycloisomerization protocol

A new practical method for the synthesis of N-fused heterocycles via the transition metal-catalyzed cycloisomerization of heterocyles possessing a propagyl group has been developed. This very mild, base- and ligand-free method allows for the synthesis of diverse fused heterocyclic cores in good to excellent yields.     

Stereoselective synthesis of hydroxylated β-aminocyclohexanecarboxylic acids

A simple synthetic approach has been developed for the regio- and diastereoselective synthesis of hydroxylated 2-aminocyclohexanecarboxylic acid stereoisomers from 1,4-cyclohexadiene by the reductive opening of appropriate epoxide intermediates derived from the corresponding bicyclic β-lactams. This method has been extended to the synthesis of these hydroxylated β-amino acids in enantiomerically pure form.     

Substrate dependent intramolecular palladium-catalysed cyclisation and subsequent β-H elimination or C-H activation: a general method for the synthesis of fused pyran rings

An efficient and convenient method for the synthesis of fused pyran rings via intramolecular palladium-catalysed cyclisation followed by β-H elimination or C-H activation has been developed. It is possible to utilise this method for the synthesis of benzopyran systems.     

Supported palladium nanoparticle‐catalysed Suzuki–Miyaura cross‐coupling approach for synthesis of aminoarylbenzosuberene analogues from natural precursor

A semi‐synthetic method has been developed for the synthesis of aminoarylbenzosuberenes (AABs) from naturally occurring himachalenes, an isomeric mixture of sesquiterpenes present in Cedrus deodara oil. Polymer‐stabilized Pd(0) nanoparticle‐catalysed Suzuki–Miyaura cross‐coupling reaction of aminovinyl bromide‐substituted benzosuberenes has been adopted for AAB synthesis. The catalyst performed well with different amine substituents, and was recycled up to five times. The synthesis of such arylated benzosuberene class of compounds from natural precursors following semi‐synthetic approaches could provide an attractive alternative method with reduced number of steps.     

Synthesis of substituted benzoxazoles by the iron(III)-catalyzed aerobic oxidation process

The FeCl₃-catalyzed aerobic oxidation process for the synthesis of benzoxazoles, benzothiazole and benzimidazole has been discovered. This method has proved to be effective to a wide range of substrates, and it has been applied for the synthesis of JTP-426467.