One-pot sequential Baylis-Hillman and Michael reactions

A new one-pot procedure for the sequential Baylis-Hillman and Michael reactions has been developed to construct two carbon-carbon bonds with three components. This procedure has been applied to combine a variety of aromatic aldehydes, β-unsubstituted acrylates and activated methide nucleophiles to generate highly diversified and functionalized organic compounds.     

One-pot, three-component synthesis of secondary amines and trisubstituted hydrazines from ketones

Various imines and hydrazones were reduced to the corresponding amines and hydrazines using borane-tetrahydrofuran complex as a reducing agent in the solution of lithium perchlorate in diethyl ether. The initial imines or hydrazones have been prepared at the same conditions just before the reduction step. Both steps were carried out in one vessel with a good yield and insignificant formation of by-products.     

Sequential three-component reactions: synthesis, regioselectivity and application of functionalized dihydropyridines (DHPs) for the creation of fused naphthyridines

Facile and efficient synthesis of tetrasubstituted 1,4- and 1,6-dihydropyridines (DHPs) has been achieved by employing three-component domino reaction using dimethyl acetylenedicarboxylate (DMAD), aliphatic amines, and α,β-unsaturated aldehyde in the presence of 30 mol % trifluoroacetic acid. Interestingly, regioselectivity for the synthesis of 1,4-dihydropyridines can be increased by using 30 mol % triflic acid. In addition, the synthesis of fused-naphthyridine derivatives has been accomplished involving imino-Diels-Alder reaction by employing 1,4-dihydropyridines, aromatic aldehydes, and aromatic amines.     

One-pot synthesis of macrocyclic compounds possessing two cyclobutane rings by sequential inter- and intramolecular [2+2] photocycloaddition reactions

Sensitized photocycloaddition reactions of 6,6′-dimethyl-4,4′-[1,3-bis(methylenoxy)phenylene]-di-2-pyrone (1) with electron-poor α,ω-diolefins such as ethylene diacrylate (2a) and polyoxyethylene dimethacrylates (2b-d) afforded site- and stereoselective macrocyclic dioxatetralactones (3a-d) and (4b) having 18- to 25-membered rings across the C5-C6 and C5′-C6′ double bonds, or C5-C6 and C3′-C4′ double bonds in 1, respectively. Similar photoreactions of 1 with electron-rich α,ω-diolefins such as poly(ethylene glycol)divinyl ether (2e and 2f) afforded crown ether-type macrocyclic compounds (5e and 5f) having 18- and 21-membered rings across the C3-C4 and C3′-C4′ double bonds in 1, respectively. The stereochemical features of 3b, 5e-xx, and 5e-nn were determined by the X-ray crystal analysis. The reaction mechanism was inferred by MO methods.     

Palladium-catalyzed sequential alkylation-alkenylation reactions: application towards the synthesis of polyfunctionalized fused aromatic rings

The synthesis of polyfunctionalized fused aromatic carbo- and heterocycles from aryl iodides and bromoenoates via a tandem palladium-catalyzed aromatic substitution intramolecular Heck sequence is reported. Using Pd(OAc)₂ and tri-2-furylphosphine (TFP) in the presence of norbornene and Cs₂CO₃ in CH₃CN at 85 °C gave a variety of functionalized bi- and tricyclic fused aromatic rings in good yield.     

One-pot and catalyst-free synthesis of thiosemicarbazones via multicomponent coupling reactions

A novel and efficient procedure for the synthesis of thiosemicarbazones has been achieved via a multicomponent and catalyst-free reaction of phenyl or p-chlorophenyl isothiocyanate, hydrazine, and aldehydes or ketones. The method afforded 20 thiosemicarbazones in good yields and short reaction time.     

One-pot three-component synthesis of indole-3-glyoxyl derivatives and indole-3-glyoxyl triazoles

A general and efficient reaction of indole with oxalyl chloride and nucleophiles providing indole-3-glyoxyl derivatives has been developed in mild conditions. In the same fashion, the other reaction involved the addition of organic azides leading to the synthesis of indole-3-glyoxyl-1,2,3-triazoles, which proceeds smoothly generating the products in moderate to high yields.     

One-pot synthesis of substituted indolines via a copper-catalyzed sequential multicomponent/C-N coupling reaction

One-pot synthesis of 2-(N-sulfonylimino)indolines has been developed. The procedure combines the copper-catalyzed three-component reaction of sulfonyl azides, o-bromophenylacetylenes, and amines and the copper-catalyzed intramolecular C-N coupling in one sequence, which afforded the products in moderate to good yields. The resulting 2-(N-sulfonylimino)indolines could be easily transformed to pharmaceutically valuable oxindoles (indolin-2-ones).     

One-pot, three-component synthesis of five-membered cyclic nitrones by addition/cyclization/condensation domino reaction

A new approach to five-membered cyclic nitrones connected with the incorporation of a planar aromatic ring system into the structure is described. This procedure is based on an allenyloxime one-pot domino transformation under simple base catalysis in alcoholic and aqueous solvents. The structure of obtained nitrones was studied by X-ray analysis and the reactivity of products in 1,3-dipolar cycloadditions was tested.     

One-pot three-component synthesis of the spiroacenaphthylene derivatives

A facile and efficient one-pot three-component synthesis of the spiroacenaphthylene derivatives was achieved, via the reaction of acenaphthequinone, malononitrile/ethylcyanoacetate and various reagents including α-methylencarbonyl compounds/enols.     

"一锅法"合成N-链烯基-(2R,3R)-O,O-二乙酰酒石酰亚胺

本文报导一种由(2R,3R)-二乙酰酒石酸酐合成N-ω-链烯基二乙酰酒石酰亚胺的简单有效的"一锅合成法", 并使总产率有大幅度的提高。     

One-pot synthesis of dendritic polyamide

Dendritic polyamides with polydispersity of 1.1–1.4 have been successfully prepared from trimesic acid, 5-aminoisophthalic acid, and 4-aminophenylpropionic acid as a core molecule, a dendron, and a spacer unit, respectively, with a one-pot procedure. This procedure involves successive activation of end carboxyl groups with the condensing agent diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate (DBOP), followed by condensation of active amide with 5-aminoisopthalic acid or 4-aminophenylpropionic acid and, finally, capping of the end carboxyl groups with p-anisidine. The structure of dendritic polyamides was investigated by ¹H-NMR spectroscopy, and it was found that the polymers obtained contained approximately 10% defects. Furthermore, the model reaction was studied to demonstrate the feasibility of dendritic polyamides. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3638–3645, 1999     

One-pot,four-component synthesis of benzylpyrazolyl naphthoquinone derivatives and molecular docking studies

A highly efficient, green, one-pot, four-component approach for the synthesis of benzylpyrazolyl naphthoquinone derivatives (5a–p) have been developed by the domino reaction of 2-hydroxy naphthoquinone, aromatic aldehyde, ethyl acetoacetate, and phenyl hydrazine derivatives in water and employed p-toluene sulfonic acid (p-TSA) as the right choice of catalyst at reflux. Docking simulation was performed to position compounds 5a, 5b, and 5g into the anaplastic lymphoma kinase (ALK) structure active site to determine the probable binding model.     

One-pot synthesis of pyrrolidino- and piperidinoquinolinones by three-component aza-Diels-Alder reactions of in situ generated N-arylimines and cyclic enamides

An efficient synthesis of hexahydropyrrolo[3,2-c]quinolin-2-ones and hexahydropyridino[3,2-c]quinolin-2-ones has been developed in moderate to high yields by one-pot two-step aza-Diels-Alder reactions of N-arylimines, formed in situ from anilines and benzaldehydes, with cyclic enamides, formed in situ from 5-hydroxypyrrolidin-2-ones and 6-hydroxypiperidin-2-ones by BF₃·OEt₂-promoted dehydration in dichloromethane at room temperature. The hexahydropyrrolo[3,2-c]quinolin-2-ones were formed as a single exo-stereoisomer in most cases and hexahydropyridino[3,2-c]quinolin-2-ones were formed as a mixture of exo- and endo-isomers favoring the endo-diastereomer.     

One-pot three-component catalytic synthesis of fully substituted pyrroles from readily available propargylic alcohols, 1,3-dicarbonyl compounds and primary amines

A simple and highly efficient method for the preparation of fully substituted pyrroles, from readily accessible secondary propargylic alcohols, 1,3-dicarbonyl compounds and primary amines, has been developed. The one-pot multicomponent reaction, which is catalysed by the system [Ru(eta(3)-2-C(3)H(4)Me)(CO)(dppf)][SbF(6)]/CF(3)CO(2)H (dppf: 1,1'-bis(diphenylphosphanyl)ferrocene), involves initial propargylation of the 1,3-dicarbonyl compound promoted by CF(3)CO(2)H and subsequent condensation between the resulting gamma-keto alkyne and the primary amine to afford a propargylated beta-enamino ester or ketone, which undergoes a ruthenium-catalysed 5-exo-dig annulation to form the final pyrrole.