Baohua Chen

CuO-promoted construction of N-2-aryl-substituted-1,2,3-triazoles via azide-chalcone oxidative cycloaddition and post-triazole arylation.

An efficient one-pot three-component stepwise approach for the synthesis of N-2-aryl-substituted-1,2,3-triazoles has been developed. By using this azide-chalcone oxidative cycloaddition and post-triazole arylation, a series of N-2-aryl-substituted-1,2,3-triazoles are readily prepared under mild conditions in excellent yields and high regioselectivity. Both the catalyst and substrates are readily available.

Conversion of tributylstannylferrocene to a variety of heteroaryl ferrocenes

Abstract Tributylstannylferrocene (Fcue5f8SnBu 3 ) was converted to a variety of heteroaryl ferrocenes, such as 2-thiophenyl, 3-thiophenyl, 3-pyridyl, 3-quinolyl, 4-oxazolyl and 4-isoxazolyl ferrocene, by using Pd-catalyzed reactions. The Stille-coupling catalyst (PdCl 2 –PPh 3 ) promotes the reaction between Fcue5f8SnBu 3 and electron-deficient heterocyclic bromides, while a modified catalyst (Pd–Ph 3 P–CuO) proves to be the choice for the coupling of Fcue5f8SnBu 3 with electron-rich heterocyclic bromides.

Copper supported on H+-modified manganese oxide octahedral molecular sieves (Cu/H-OMS-2) as a heterogeneous biomimetic catalyst for the synthesis of imidazo[1,2-a]-N-heterocycles

Copper supported on acid-modified manganese oxide octahedral molecular sieves (Cu/H-OMS-2) was prepared and found to be a versatile catalyst for the oxidative synthesis of 3-aroylimidazopyridines with a broad substrate scope. Cu/H-OMS-2 that was characterized by BET, XRD, XPS, FTIR, TEM, SEM, H2-TPR and O2-TPD techniques could also be used to synthesize 3-aroylimidazopyrimidines and applied in one-pot, three-component reactions of ketones, aldehydes and 2-aminopyridines. The catalytic system employs low loading Cu as the catalytic metal and support H-OMS-2 as the electron-transfer mediator (ETM) to sequentially lower the redox energy barrier, which generates a low-energy pathway and enables the reaction to proceed in a biomimetic way. Moreover, Cu/H-OMS-2 could be reutilized 4 times with a slight decrease in the catalytic activity.

Preparation of 1,5-diketone derivatives containing ferrocenyl by Michael reaction under solvent-free condition

Abstract This work describes a fast, mild, convenient and simple method for preparing 1,5-diketones by Michael reaction under solvent-free condition. Fourteen new 1,5-diketone compounds containing ferrocenyl were synthesized. The product 1f is discussed from its 1 H-NMR spectrum.

SOLID-PHASE SYNTHESIS OF FERROCENYLCHALKONE

ABSTRACT A convenient and rapid aldol condensation between acylferrocene and ketone or aldehyde is performed in excellent yield in presence of solid NaOH under mild and solvent-free ‘dry’ conditions.

(E)-cinnamoylferrocene S-methylcarbo-dithioylhydrazone and its complexes

The new organometallic compound, (E)-cinnamoylferrocene S-methylcarbodithioylhydrazone (HCfmc) and its complexes with some metals(II) acetates, M(Cfmc).OAc.nH(2)O (M = Ni2+, Cu2+, Zn2+, Cd2+ Hg2+ and Pb2+; n = 0 - 2) were prepared and characterized by LR, UV, H-1 NMR. It is shown that the HCfmc is a bidentate ligand with trans configuration which coordinates with the metal through the azomethine nitrogen and thioenolic sulfur atom. One acetate ion coordinates as a bidentate ligand.

OMS-2-Supported Cu Hydroxide-Catalyzed Benzoxazoles Synthesis from Catechols and Amines via Domino Oxidation Process at Room Temperature

In the presence of manganese oxide octahedral molecular sieve (OMS-2) supported copper hydroxide Cu(OH)x/OMS-2, aerobic synthesis of benzoxazoles from catechols and amines via domino oxidation/cyclization at room temperature is achieved. This heterogeneous benzoxazoles synthesis initiated by the efficient oxidation of catechols over Cu(OH)x/OMS-2 tolerates a variety of substrates, especially amines containing sensitive groups (hydroxyl, cyano, amino, vinyl, ethynyl, ester, and even acetyl groups) and heterocycles, which affords functionalized benzoxazoles in good to excellent yields by employing low catalyst loading (2 mol % Cu). The characterization and plausible catalytic mechanism of Cu(OH)x/OMS-2 are described. The notable features of our catalytic protocol such as the use of air as the benign oxidant and EtOH as the solvent, mild conditions, ease of product separation, being scalable up to the gram level, and superior reusability of catalyst (up to 10 cycles) make it more practical and environmentally friendly for organic synthesis.

Convenient Synthesis of Aryl Ferrocenyl Ketone via Palladium‐Catalyzed Carbonylation Coupling

Abstract A series of aryl ferrocenyl ketones were prepared from iodoferrocene, phenylboronic acids, and CO via palladium‐catalyzed carbonylation coupling in a short time. The procedure was efficient and convenient and avoided formation of diacylated derivatives compared with currently available Friedel–Crafts acylation methodologies.

Preparation of ferrocenyl mono- and dienone derivatives through aldol condensation of 1,1′-diacetylferrocene with aromatic aldehydes in dry conditions

Abstract 1,1′-Diacetylferrocene was condensed with aromatic aldehydes without solvent in the presence of solid NaOH. Diacetylferrocene can give good yields of mono- or diene with either one or two molecules of a wide range of aldehydes depending only on the stoichiometry. Cyclization to ferrocenphane does not occur in this condition.

Transition metal(II) complexes of (E)-cinnamoylferrocene (S)-methylcarbodithioylhydrazone

A new organometallic ligand, (E)-cinnamoylferrocene (S)-methylcarbodithioylhydrazone (HCfmc) and six transition metal(II) complexes thereof M(Cfmc)2·nH2O (M=Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+; n=0–2) have been prepared and characterized by elemetal analyses, i.r., u.v., 1H-n.m.r. spectra, electrochemical properties, fluorescence spectra and molar conductances. The HCfmc ligand acts as a bidentate donor, coordinating to the metal ions via nitrogen and sulfur atoms with a trans-configuration.