A Convenient Synthesis of Functionalized Dibenzotellurophenes and Related Compounds via the Intramolecular Telluro Coupling Reaction. The Positive Effect of Heavy Chalcogen Atoms on the Molecular Hyperpolarizability of a Captodative Conjugation System
摘要:
Nitro-containing dibenzotellurophenes and related compounds, which are otherwise laborious to obtain, were prepared by the reaction of 2,2'-diiodobiphenyl derivatives with an in situ prepared tellurium-copper slurry. Partial reduction of 3,7-dinitrodibenzotellurophene using hydrazine hydrate/palladium on charcoal led to 3-amino-7-nitrodibenzotellurophene, which was found to exhibit a relatively large third-order molecular hyperpolarizability gamma (1.4 x 10(-31) esu) in the measurement of degenerated four-wave mixing (DFWM) as compared with 4-amino-4'-nitrobiphenyl and other previously reported compounds, confirming the positive effect of tellurium atom on the nonlinear optical property of a captodative conjugation system.
Preparation of N-substituted phthalimides by the palladium-catalyzed carbonylation and coupling of o-dihalo aromatics and primary amines
摘要:
A novel method for the formation of N-substituted phthalimides is described which is based on the palladium-catalyzed carbonylation and coupling of o-dihalo aromatics and primary amines. Optimal conditions established for the reaction using o-diiodobenzene and aniline were DMAc (0.2 M), 115-degrees-C, 90 psi of CO, 3% PdCl2L2, and 2.4 equiv of DBU. This process is tolerant of a wide variety of functional groups and gives good yields of the desired products. Variables such as temperature, catalyst type and loading, CO pressure, solvent, and base were examined to optimize this reaction. The reaction of aniline with 1,2-dibromocyclopentene under similar conditions gave a variety of products.
We have developed a convenient one-step preparation of aromatic and some heterocyclic iodides by the sequential diazotiza- tion-iodination of the aromatic amines with a KI/NaNO2/p-TsOH system in acetonitrile at room temperature. This method has general character and allows aryl iodides with either donor or acceptor sub- stituents in various positions to be obtained from the corresponding amines in
Iodination of nitroarenes by a superactive reagent based on iodine chloride
作者:V. K. Chaikovskii、T. S. Kharlova、V. D. Filimnov
DOI:10.1007/bf02495292
日期:1999.7
Iodinechloride reacts with Ag2SO3 in H2SO4 to give a new superelectrophilic reagent capable of iodinating nitrobenzene, halogenated nitrobenzenes, nitrotoluenes, and aromatic compounds with two nitro groups in the ring. Mononitroarenes are easily iodinated at 0–20°C, while dinitroarenes require heating to 100–170°C.
Formation of Arenesvia Diallylarenes: Strategic Utilization of Suzuki–Miyaura Cross-Coupling, Claisen Rearrangement and Ring-Closing Metathesis
作者:Sambasivarao Kotha、Vrajesh R. Shah、Kalyaneswar Mandal
DOI:10.1002/adsc.200600469
日期:2007.5.7
benzoannulation are reported. The first strategy is based on the Suzuki–Miyauracross-coupling reaction. To this end, various ortho-diallylbenzene derivatives were prepared from the corrresponding diiodo derivatives by an allylation strategy using an allylboronate as coupling partner. These diallyl derivatives were subjected to a ring-closingmetathesis (RCM) and one-pot dichlorodicyanoquinone (DDQ) oxidation
Stepwise Assembly of Site Specifically Functionalized Dehydrobenzo[18]annulenes
作者:Joshua J. Pak、Timothy J. R. Weakley、Michael M. Haley
DOI:10.1021/ja991749g
日期:1999.9.1
Site specifically functionalized dehydrobenzo[18]annulenes (DBAs) with previously inaccessible topologies (C2v and Cs symmetry) were prepared by utilizing an in situ protiodesilylation/alkynylation reaction. By application of a stepwise syntheticroute, donor and/or acceptor functional groups were introduced to the annulenic core in a designed manner. The electronic absorption spectra of the DBAs revealed
NOVEL DIAMINOPHENOTHIAZINE COMPOUNDS, A METHOD FOR PREPARING SAME AND USES THEREOF
申请人:Galey Laurent
公开号:US20100204215A1
公开(公告)日:2010-08-12
Novel 2,8-diaminophenothiazine compounds, a method for preparing the same, and uses of the novel 2,8-diaminophenothiazine compounds in the field of treating liquid or gaseous fluids, especially influents and industrial or domestic effluents.