Mild and efficient palladium-catalyzed intramolecular direct arylation reactions
作者:Marc Lafrance、David Lapointe、Keith Fagnou
DOI:10.1016/j.tet.2008.01.057
日期:2008.6
been evaluated in the context of intramoleculardirect arylation reactions. Under the optimal conditions, arylation of simple arenes can be performed under very mild conditions, with heating to 50 °C. The role of the pivalic acid additive is rationalized by invoking a concerted palladation–deprotonation pathway where the pivalate is behaving as either an intramolecular base from the palladium metal or
Ultrasound-promoted intramolecular direct arylation in a capillary flow microreactor
作者:Lei Zhang、Mei Geng、Peng Teng、Dan Zhao、Xi Lu、Jian-Xin Li
DOI:10.1016/j.ultsonch.2011.07.008
日期:2012.3
An intramoleculardirectarylation of various aryl bromides was performed using ultrasonic irradiation and a continuous flow capillary microreactor. The present procedure provided a higher functional group tolerance, ligand-free, milder reaction conditions and a shorter reaction time for the directarylation compared with the conventional methods. The ultrasonic irritation not only greatly promoted
In this Communication, we describe direct arylation reactions with improved scope and catalyst activity for the intramolecular formation of biaryl compounds. This was achieved through the establishment of a highly active and robust catalyst system and the subsequent development of a novel phosphine ligand 27. The enhanced catalytic activity extends these transformations to include previously unreactive and poorly reactive substrates, and allows for very low catalyst loadings to be employed-as little as 0.1 mol %.
[EN] Certain novel heterocyclic 1,4-disubstituted benzene N-oxide derivatives have provided unexpected insecticidal and acaricidal activity. These compounds are represented by formula (I) wherein R1, R2, B, D, T, U, m, and n are fully described herein. In addition, compositions comprising an insecticidally effective amount of at least one compound of formula I, and optionally, an effective amount of at least one of a second compound, with at least one insecticidally compatible carrier are also disclosed; along with methods of controlling insects comprising applying said compositions to a locus where insects are present or are expected to be present. [FR] Certains nouveaux dérivés de 1,4 N-oxyde de benzène disubstitués hétérocycliques ont exercé une action insecticide et acaricide inattendue. Ces composés sont représentés par la formule (I), dans laquelle R1, R2, B, D, T, U, m, et n sont décrits de manière exhaustive. De plus, les compositions de l'invention contiennent une quantité suffisante pour être efficace d'un point de vue insecticide d'au moins un composé de formule (I), et éventuellement, une quantité efface d'au moins un second composé, associés à un support compatible d'un point de vue insecticide. Par ailleurs, l'invention concerne des procédés de lutte contre les insectes qui consistent à appliquer lesdites compositions à un site contenant ou censé contenir des insectes.