Triazole-gold (TAAu) catalyzed three-component coupling (A3 reaction) towards the synthesis of 2, 4-disubstituted quinoline derivatives

A gold-catalyzed three-component coupling reaction (A3 reaction) was developed as an efficient approach for the synthesis of challenging 2,4-disubstituted quinoline derivatives. Compared to previously reported Cu/Au bi-catalyst system, this protocol enables achieving A3 reaction only in the presence of triazole-gold catalyst. Notably, 4-alkyl substituted or 2-alkyl substituted quinoline derivatives were obtained with good yields, which highlighted the unique advantage of this new strategy.     

Synthesis of alkoxymethyl derivatives of resorcinarene via the Mannich reaction catalysed with iminodiacetic acid

The conditions of a simple synthesis of tetra(alkoxymethyl) derivatives of resorcinarene via the Mannich reaction catalysed with iminodiacetic acid are described. A possibility of high yield synthesis of such derivatives for the selected straight-chain alcohols is shown. A possible mechanism of this reaction is suggested.     

Iron(III)-catalyzed synthesis of selenoesters from α-amino carbonyl derivatives at room temperature

An Fe(III)-catalyzed efficient method has been developed for the synthesis of selenoester derivatives in high yields through the coupling of α-amino carbonyl/glycine derivatives and diselenides under ambient air. A library of benzoselenoate derivatives having a variety of substituents has been synthesized. A plausible reaction pathway has been predicted. Experimental results suggest that the reaction proceeds through a radical pathway. Operational simplicity, compatibility with various α-amino carbonyls and diselenides, high yields, fast reaction and mild reaction conditions are the notable advantages of this procedure. We have also shown the practical application of the synthesized selenoesters which is useful to generate peptide bonds in biological sciences.     

Efficient synthesis of phenanthridinone derivatives via a palladium-catalyzed coupling process

A palladium-mediated domino reaction was developed to conveniently synthesize phenanthridinone derivatives. Phosphine ligand 1 strongly promotes the domino process, which includes aryl-aryl coupling and C-N bond formations concomitant with a deamidation reaction. The versatility and applicability to a broad range of substrates make this reaction useful for the development of bioactive derivatives. [reaction: see text].     

Simple and one-pot protocol for synthesis of indene-spiro-oxindoles involving tandem Prins and Friedel-Crafts reactions

[reaction: see text] A simple and one-pot protocol for the synthesis of indene-spiro-oxindole derivatives via TiCl4-mediated reaction between 1,1-diarylethylenes and isatin derivatives involving construction of two carbon-carbon bonds through tandem Prins and intramolecular Friedel-Crafts (PFC) reactions has been described. A plausible mechanism for this transformation is also presented.     

Unexpected formation of fluorine-containing tetrahydrocarbazole during the reaction of indole, paraformaldehyde, and fluorine-containing β-ketoesters

A surprise and mild method to prepare fluorine-containing indole derivatives through a one-pot three-component condensation reaction sequence is presented. To our surprise, during the reaction of preparation of fluorine-containing indole derivatives, unexpected formation of fluorine-containing tetrahydrocarbazole was found. Moreover, this method has been demonstrated in the preparation of functionalized polycyclic indole derivatives in a straightforward and atom-economical manner.     

Convergent integration of two self-labor domino sequences: a novel method for the synthesis of oxazole derivatives from methyl ketones and benzoins

A highly efficient method for the synthesis of oxazole derivatives from methyl ketones, benzoins and ammonium acetate has been established via a novel strategy-convergent integration of two self-labor domino sequences. Owing to the simple and readily available starting materials, mild reaction conditions, facile operation, and the high bioactivity of oxazole derivatives, this reaction promises diverse applications in medical chemistry. Additionally, this reaction could provide an efficient example for self-labor synthesis strategy of organic compounds.     

A facile [4+1] type synthetic route to thiophenes from dienol silyl ethers and elemental sulfur

A facile method for the synthesis of thiophene derivatives via the reaction of readily accessible dienol silyl ethers with elemental sulfur is described. Dienol silyl ethers and elemental sulfur, when heated at 180 °C in the presence of MS4A, provided 3-siloxythiophene derivatives in yields up to 98%. In this reaction, thiophene derivatives might be formed through 1,2-dithiines and eight-membered cyclic tetrasulfides.     

A Practical method for preparation of β-glycosides of N-acetylglucosamine

A mild and efficient method for preparation of GlcNAc derivatives by reaction of glycosyl acceptors with glycosyl oxazolines has been developed. The key feature is use of Yb(OTf)₃ as promoter, requiring moderate reaction times and equivalence stoichiometry. We anticipate application in the preparation of a wide range of derivatives of this biologically important class of building blocks.     

Regiodivergent synthesis of functionalized indene derivatives via Pt-catalyzed Rautenstrauch reaction of propargyl carbonates

A regiodivergent synthesis of functionalized indene derivatives from a Pt-catalyzed Rautenstrauch reaction of propargyl carbonate is described. A one-pot Rautenstrauch/Tsuji-Trost reaction delivering 2-indanones was realized efficiently using this methodology.     

One-pot synthesis of novel pyrrolo-1,4-benzoxazines via a three- component reaction of 2-amino phenols,acetylenic esters and nitrostyrene derivatives简

A simple and efficient synthetic protocol has been developed using a one-pot, three-component reaction involving 2-amino phenols, dialkyl acetylene dicarboxylates and nitrostyrene derivatives. Utilizing this protocol, a variety of novel pyrrolo-1,4-benzoxazine derivatives were synthesized in excellent yields.     

固定化脯氨酸及其衍生物用于催化不对称有机合成

脯氨酸及其衍生物作为有机手性催化剂,在不对称有机合成中得到广泛应用。该类催化剂具有结构简单、来源丰富和选择性高等优点,但仍存在催化剂用量大、难以回收以及无法重复利用等不足。近年来,随着固定化技术的发展,固定化脯氨酸及其衍生物受到广泛关注。固定化脯氨酸及其衍生物催化剂可以简化不对称催化中产物的分离过程,实现催化剂的便利回收与循环使用。本文综述了固定化脯氨酸及其衍生物的制备及在催化不对称有机合成(如Aldol反应、Michael加成反应、Mannich反应等)中的研究进展。     

DMAP-catalyzed four-component one-pot synthesis of highly functionalized spirooxindole-1,4-dihydropyridines derivatives in aqueous ethanol

An efficient, clean, and environmental friendly ‘one-pot’ four-component reaction was developed for assembling a novel type of spirooxindole derivatives containing dihydropyridine and pyrrolidinone. The reaction could be easily performed in aqueous ethanol with 4-DMAP as catalyst in good yields. The high efficiency and the simple and mild condition of the reaction, in addition with its avoidance of time-consuming, costly syntheses, and tedious workup, endowed the reaction with application significance. A series of spirooxindole derivatives were therefore prepared in excellent yields by using this ‘one-pot’ four-component reaction method.     

Synthesis of planar chiral selenide derivatives of ferrocenyl-oxazoline and their application in enantioselective palladium catalyzed allylic substitution reaction

A series of chiral selenide derivatives of ferrocenyl-oxazolines was synthesized and applied in a palladium catalyzed allylic reaction, with high enantioselectivity and moderate yield: the role of planar chirality in this reaction was also studied.     

Chromium-mediated synthesis of polycyclic aromatic compounds from halobiaryls

[reaction: see text] Reaction of 2,2'-dihalobiphenyl with butyllithium followed by the addition of chromium(III) chloride and alkynes afforded the corresponding phenanthrene derivatives via formal [4 + 2] cycloaddition. A variety of alkynes could be used for this reaction, such as alkyl, aryl, silyl, and alkoxycarbonyl alkynes. Repetitive process of the reaction gave more extended polycyclic compounds such as benzo[g]chrysene and azacyclopentaphenalene derivatives.     

Hydrogen bond assisted synthesis of azacyclophanes from l-tyrosine derivatives

Spectroscopic and computational studies reveal that a dimer of two units of l-tyrosine derivatives, joined by intermolecular hydrogen bonds, acts as a template in the synthesis of azacyclophanes from l-tyrosine derivatives and formaldehyde via double Mannich type reaction. When the reaction is performed with l-tyrosine, the absence of this template leads to linear products. A new azacyclophane (benzoxazinephane) was synthesized by condensation of l-tyrosine isopropyl ester and formaldehyde.     

Amide-Assisted Rearrangement of Hydroxyarylformimidoyl Chloride to Diarylurea

A novel amide-assisted rearrangement reaction of hydroxybenzimidoyl chloride has been established for the efficient synthesis of 1,3-diphenylurea derivatives. A variety of electronically and sterically different 1,3-diphenylurea derivatives can be obtained in good to excellent yields, and a proposed reaction mechanism is also presented.     

Alder-ene reaction of aryne with olefins

A novel intermolecular Alder-ene reaction based on aryne and olefins was developed. We performed this transformation under mild conditions such as at room temperature, and this reaction displayed high selectivity and good yields only in the presence of CsF. Hence, the intermolecular Alder-ene reaction of aryne with olefins provides an effective route to synthesize derivatives of olefins.     

Highly rapid and direct synthesis of monoacylated piperazine derivatives from carboxylic acids under mild conditions

A series of monoacylated piperazine derivatives were obtained by the reaction of carboxylic acids with 2-chloro-4,6-dimethoxy-1,3,5-triazine in dichloromethane at room temperature. Good to excellent yields, short reaction times and mild reaction conditions are important features of this methodology.     

Exo ring opening in methyl pheophorbide a 132-amide derivatives under the action of amines

Russian Chemical Bulletin - A reaction of methyl pheophorbide a 132-amide derivatives with amines was studied to explore a possibility of using this reaction in the synthesis of new macrocyclic...