A visible‐light‐induced intramolecular crossed [2 + 2] cycloaddition reaction of allene‐tethered alkylidenecyclopropanes was reported in this paper. The reactions were conducted under mild conditions using Iridium(III) catalyst FirPic as a photosensitizer for energy transfer, affording bridged bicyclic alkenes moderate to good yields with excellent regioselectivity and stereoselectivity through the regulation substituents at olefin’s terminal position. Meanwhile, computational study...

A facile synthetic method of functionalized pyrrolo[1,2-a]indoles has been developed via a thermally-induced ring-opening and cyclization reaction from aniline-tethered alkylidenecyclopropanes with aldehydes.

The chemoselective [4+2] vs. [2+2] cycloaddition between allenoates and dithioesters can be controlled by switching the nucleophilic amine catalyst. two modes of cyclizations represent first example controllable annulations dienophiles catalyzed amine. These are useful in offering a divergent synthesis sulfur-containing heterocycles. On basis this investigation, it realized that with vicinal electron-withdrawing group react not only like Michael acceptor but also as ketone or imine.

In the Baylis–Hillman reaction of N-benzylidene-4-methylbenzenesulfonamide with cyclohex-2-en-1-one or cyclopent-2-en-1-one, we found that, in presence a catalytic amount DMAP, can be greatly accelerated to give normal adduct 1 3 good very high yields; moreover, using PBu3 as Lewis base adducts could obtained yields within 5 h, however, DBU cyclohex-2-en-1-one, besides abnormal 3-aryl-2-[(4-methylphenyl)sulfonyl]-2-azabicyclo[2.2.2]octan-5-one 2 was formed at same time; substituent's effects...

A facile synthetic method for preparation of bicyclo[4.2.0] nitrogen heterocycles has been developed via a thermal induced intramolecular [2 + 2] cycloaddition reaction allene-ACPs. The DFT calculations indicate that this proceeds in concerted manner and strained small ring is essential.

In this article, we described the use of an easily available polymer‐based hafnium chloride and montmorillonite KSF catalyst (HfCl4/KSF‐polyDMAP) in transamidation under relatively mild conditions. This metal can be recovered reused reaction to give corresponding amides good yields.

Abstract Phenolic compounds can be nitrated with 60 % nitric acid (1.2 equiv.) in the presence of catalytic amounts a Zr or Hf oxychloride complex and montmorillonite KSF to give corresponding products good yields heterogeneous system. The co‐catalyst easily recovered reused next batch nitration. This is practical process for nitration phenolic clean way. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Thermally-induced intramolecular [2 + 2] cycloadditions of acrylamide-tethered alkylidenecyclopropanes to generate a series novel cyclobutane-containing spiro[2.3]hexanes were disclosed.

[reaction: see text] A new general method for the synthesis of 5,6-dihydropyran-2-ones from cyclopropyl aryl ketones (monoactivated cyclopropanes) and alpha-ketoesters in good to excellent yields has been developed. The process involves a cascade reactions, including nucleophilic ring-opening reaction monoactivated cyclopropane by H2O, Lewis acid mediated transesterification, an aldol type reaction.

TMSOTf-mediated reactions of 2-aryl-1-(1-phenylcyclopropyl)ethanones 1 with allenic esters afford a novel method for the synthesis 6-methyl-3a,7-diaryl-3,3a-dihydro-2H-benzofuran-4-one derivatives 2 in moderate yields. In addition, we also found that 1-cyclopropyl-2-arylethanones ethyl acetoacetate can provide corresponding 2,3-dihydrobenzofuran-4-ol and dihydrofuro[2,3-h]chromen-2-one yields via sequential reaction involving nucleophilic ring-opening cyclopropane by H2O, one intermolecular...

A catalyst‐free self‐catalyzed [3+2] cycloaddition reaction of 3‐isothiocyanato oxindoles with vinylpyridines has been established, affording the desired products in high yields (up to 97 %) moderate good diastereoselectivities 11:1) under mild conditions. The mechanism investigated by control experiments, DFT calculations pK a values and kinetic studies, revealing that this featured mutual activation between oxindole vinylpyridine generate reactive species. Furthermore, these could be...

C2-Symmetric optically active pyrrolidinium salts were synthesized by the reaction of 2, 3 : 4, 5-di-O-benzylidene-(3R, 4R)-dihydroxy-(2S, 5S)-bis(hydroxymethyl)pyrrolidine (2), (3R, 4R)-dimethoxy-(2S, 5S)-bis(methoxymethyl)-pyrrolidine (3), 5-Di-O-benzylidene-(3R, 4R)-dihydroxy-N-(2-hydroxyethyl)-(2S, 5S)-bis(hydroxymethyl)-pyrrolidine (5), and 4R)-dimethoxy-N-(2-hydroxyethyl)-(2S, 5S)-bis(methoxymethyl)pyrrolidine (7) with methyl iodide or α, ω-dibromoalkanes. They exhibited low chiral...

Abstract This paper reports the full details of Lewis acid SnCl 4 ‐mediated reactions cyclopropyl alkyl ketones with α‐keto esters under mild conditions. In general, it was found that four products were formed in ketones. However, by controlling aldol reaction process, corresponding spiro‐γ‐lactone can be exclusively obtained moderate to good yields stereoselectivities via sequential nucleophilic ring‐opening cyclopropane H 2 O, type and subsequent cyclic transesterification mediated acid....

Abstract Synopsis. Upon UV irradiation in methanol,diaryl triphenylmethylphosponate underwent three types of elimination two aryl groups to give biaryls: the first is an α,α-elimination phenyl from a triphenylmethyl group which leads formation corresponding carbene intermidiate; second diaryl ester afford biaryl; third and both moieties arylbenzene.

The helium cryo-plant is an indispensable subsystem for the application of low temperature superconductors in large-scale scientific facilities. However, it important to note that requires stable operation and consumes a substantial amount electrical power its operation. Additionally, construction incurs significant economic costs. To achieve necessary cooling capacity while reducing consumption ensuring stability feasibility, constrained multi-objective optimization performed using interior...

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Abstract Herein, the first example of gold‐catalyzed benzylation (hetero)aryl boronic acids with (hetero)benzyl bromides to give corresponding cross‐coupling products in moderate good yields is reported. The reaction proceeds through a possible intermolecular S N 2‐type pathway wide variety di(hetero)arylmethanes as desired products. An intriguing mechanism has been proposed on basis control experiments, 31 P‐NMR spectroscopic detection and DFT calculations.

In the title compound, [Cu(SO(4))(C(15)H(11)N(5))(H(2)O)]·CH(3)OH·2H(2)O, Cu(II) ion is in a distorted square-pyramidal geometry, which three N atoms from chelating 1-(1,10-phenanthrolin-2-yl)-1H-pyrazol-3-amine ligand and one O atom sulfate anion define basal plane coordinating water mol-ecule located at apex. crystal, hydrogen-bonding inter-actions involving solvent mol-ecules, methanol amine group (one with an intra-molecular inter-action to of atoms) complex are observed. π-π between...

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