1,5,9-环十二碳三烯的阳离子型跨环齐聚合反应

本文研究1,5,9-环十二碳三烯在阳离子型引发剂AlCl3和BF3.OEt2催化下进行的跨环聚合反应, 考察各种反应条件对跨环聚合反应的影响, 产物为白色粉末, 分子量均在1096-1431之间对其溶解性, 核磁共振和红外光谱的分析, 确认了它的结构。     

Synthesis of some cycloundecane derivatives from 1,5,9-cyclododecatriene

Summary Cycloundecanecarboxylic and cycloundecadienecarboxylic acids were synthesized from cis-trans-trans-1,5,9-cyclododecatriene.     

Capillary gas chromatography of hydrogenation products of 1,5,9-cyclododecatriene stereoisomers

Summary The separation of the products obtained by the hydrogenation of 1,5,9-cyclododecatriene stereoisomers on fused-silica capillary columns coated with dimethylsilicone and cyanopropylmethylsilicone stationary phases was investigated. Retention indices of cyclododecatrienes, cyclododecadienes, cyclododecenes and cyclododecane were determined at three temperatures. The respective standard deviations were 0.3 and 0.6 i.u. The influence of the polarity of the stationary phases on the chromatographic retention of these cyclic hydrocarbones is discussed.     

A convenient route to diazepines by intramolecular cyclisation of carbonylazides

The appropriate substituted carbonylazides I treated with warm acetic acid give the corresponding acetamide IV or the cyclic lactam VI . This is a convenient route to 10,11-Dihydro-5H-pyrrolo[1,2-a][1,4]-benzodiazepin-11-one and 10,11-Dihydro-4H-thieno[2,3-e]pyrrolo[1,2-a][1,4]diazepin-10-one.     

Kinetics of homogeneous acetoxylation of cyclododecene and 1,5,9-cyclododecatriene catalyzed by Pd(OAc)2

The kinetics of acetoxylation of cyclododecene and (E,E,E)-1,5,9-cyclododecatriene catalyzed by Pd(OAc)₂ has been studied in glacial acetic acid solutions at 323–343 K and atmospheric pressure. The experimental data were described by kinetic equations of the Michaelis-Menten type.     

An extensive study of bromination of cis,trans,trans-1,5,9-cyclododecatriene: product structures and conformations

Bromine has been added to cis,trans,trans-1,5,9-cyclododecatriene under various reaction conditions. All expected direct addition products have been isolated, and their structures have been determined by microanalysis, NMR and X-ray crystallography. Advanced NMR techniques were used to determine solution conformations of several of the compounds, enabling comparison with the solid-state conformations obtained by crystallography.     

Tailor-made synthesis of various backbone-substituted imidazolinium salts by triflic anhydride mediated intramolecular cyclisation

We have found a Tf(2)O-mediated intramolecular cyclization reaction and have revealed an intriguing stereoselectivity and a regioselectivity during the preparation of intermediate alcohols, which allow for the tailor-made synthesis of various backbone-substituted imidazolinium salts, and structurally specific syn-4,5-disubstituted imidazolinium salts.     

A new type of acid-induced intramolecular cyclisation of Knoevenagel condensation products in the carbohydrate field. Stereochemical control of the cyclisation process.

The products of the Knoevenagel reaction between methyl acetoacetate and aldehydopentoses undergo various cyclisation processes when treated with trifluoroacetic acid in aprotic solvents which are controlled by the sugar configuration at C-2 and C-3.     

Intramolecular cyclization of Z,E,E-1,5,9,-cyclododecatriene by the Cp2TiCl2?LiAlH4 system

The system Cp₂TiCl₂–LiAlH₄, in the absence of ethereal solvents, catalyzes the intramolecular cyclization of Z,E,E-1,5,9-cyclododecatriene, yielding a mixture of C₁₂ hydrocarbons consisting mainly of cis, anti, cis-and cis, syn, trans-tricyclo [7.3.0.0^2,6] dodec-7-ene and 5,6,7,8,9,10-hexahydrobenzocyclooctene.

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Cp₂TiCl₂–LiAlH₄, , Z,E,E,-1,5,9-, C₁₂, , , - , , - [7.3.0.0.^2,6] -7, 5,6,7,8,9,10-.

     

Decomposition of cumene hydroperoxide in the presence of 1,5,9-cyclododecatriene catalyzed by MoO2 (ACAC)2: A kinetic study

The kinetics of decomposition of cumene hydroperoxide in the presence of 1,5,9-cyclododecatriene, catalyzed by MoO₂(acac)₂ has been studied at constant temperature (303 K) and at atmospheric pressure. The influence of substrate, catalyst and product concentrations on the rate has been established. The rate and equilibrium constants have been calculated.

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1,5,9-. MoO₂(acac)₂. , .

     

Extending the Curtin–Hammett principle: the relative rates of intramolecular cyclisation versus intermolecular processes

A common tactic for synthetic chemists is to employ high dilution to ensure cyclisation is favoured over intermolecular processes. This intuitive strategy is ubiquitous in synthesis, although a quantitative analysis of these systems has not previously been proposed. In this Letter a theoretical analysis of the Curtin–Hammett principle when applied to systems in which the two equilibrating reactive species each undergo reactions of different orders is reported. This quantitative analysis predicts that a change in product distribution will be observed over time (under fixed conditions). However, the product ratios may be controlled by the addition of excess reagent(s) or by altering their concentration(s), consistent with established best practice (i.e., high dilution to maximise the formation of cyclised products, and high concentrations of reagents to maximise the formation of products resulting from intermolecular reactions).     

Formation of N-bridgehead 1,2,5-thiadiazolium and selenadiazolium rings through an intramolecular cyclisation reaction

Treatment of N-lithiopyridylketimide derivatives Li[R(C=N)py] (R=Ph, py) with ECl(2) (E=S, Se) affords the fused thiadiazolium and selenadiazolium salts [RC(6)H(4)N(2)E]Cl [1]Cl and [2]Cl containing a bridgehead N atom through intramolecular coordination.     

Silver-catalysed intramolecular cyclisation of 2-alkynylacetophenones and 3-acetyl-2-alkynylpyridines in the presence of ammonia

Silver-catalysed/microwave-assisted domino reactions of 2-alkynyl-acetophenones and 3-acetyl-2-alkynylpyridines in the presence of ammonia are widely described. In most cases the reaction give a mixture of the imino- and carbo-cyclisation products, with a general preference for the former. A plausible mechanism is proposed and the dual activity of silver salts is supported by NMR experiments.     

Synthesis of bridged carbocyclic systems related to diterpenes involving intramolecular cyclisation of diazomethyl ketones

The tricyclic dienediones 5,6 and 7 have been synthesised for entry into the ring systems of the tetracyclic diterpenes atisirene (1), phyllocladene (3) and hibaene (4) respectively.     

Efficient Horner-Wadsworth-Emmons intramolecular cyclisation of a N-substituted phthalimide promoted by KF-Alumina: a general tool for the synthesis of functionalised isoindolinones

An intramolecular Horner-Wadsworth-Emmons reaction promoted by KF-Alumina involving a N-substituted phthalimide, cleanly and efficiently furnishes an interesting α,β-unsaturated tricyclic enone which may undergo selective alkylations at the α′-position.     

Delineating ligand effects in intramolecular aryl amidation reactions: formation of a novel spiro-heterocycle by a tandem cyclisation process

Ligand effects for intramolecular Pd-catalysed aryl amidation reaction were examined for the synthesis of seven-membered benzolactam rings. In an attempt to produce an eight-membered ring, tandem C-N/C-O bond forming reactions occurred to give a novel spiro-benzofuran-lactam structure.     

Electrogenerated Nickel(I) complexes as catalysts for the intramolecular radical cyclisation of unsaturated α-bromoesters

The indirect electroreduction of unsaturated α-bromoesters using Ni(II) complexes as electron-transfer mediators is achieved in N,N′-dimethylformamide by constant current electrolysis between a cathode and a sacrificial anode in a diaphragmless cell. Cyclic compounds are obtained in moderate to good yields in conditions that avoid the usual preparation using organotin reagents.