نتایج جستجو برای: phosphines

تعداد نتایج: 579  

Journal: :Synthesis 2021

Abstract (4+3)-Annulations are incredibly versatile reactions which combine a 4-atom synthon and 3-atom to form both 7-membered carbocycles as well heterocycles. We have previously reviewed transition-metal-catalyzed (4+3)-annulations. In this review, we will cover examples involving bases, NHCs, phosphines, Lewis Brønsted acids some rare of boronic acid catalysis photocatalysis. analogy our pr...

Journal: :Organic & biomolecular chemistry 2013
Xin Li Feng Wang Nan Dong Jin-Pei Cheng

A regioselective [3 + 2] cycloaddition of benzofuranone type active olefins with allenoates catalyzed by trivalent phosphines has been developed, which provided an easy access to enriched functionalized spirocyclic benzofuranones. The reactions accommodated a number of benzofuranone type electron-deficient olefins and allenoates to give the desired 3-spirocyclopentane benzofuran-2-ones or 2-spi...

Journal: :Chemical communications 2018
F Schömberg Y Zi I Vilotijevic

Ynones are efficiently reduced with a mild hydride donor in the presence of a catalytic amount of nucleophilic phosphines. The reactions are selective 1,2-reductions that give propargyl alcohols in yields of up to 96%. It is proposed that success in these reactions depends on the activation of ynones by a Lewis base catalyst. A protic additive plays a key role in suppressing the undesired react...

2018

An overview is given of the chemistry of tris(azolyl)phosphines with focus on their preparation and application in coordinationand organometallic chemistry and catalysis. These systems share with the more abundant tris(pyrazolyl)borates and -methanes the ability to function as tridentate nitrogen ligands with hemilabile character, but the additional phosphine donor site grants them bifunctional...

2007
Apollinaire Munyaneza Muhammad D. Bala Neil J. Coville Helgard G. Raubenheimer

Reactions of (η-RC5H4)Fe(CO)2I (R = H, Me) complexes with phosphine ligands PR′3 (R′ = Ph, m-Tol, p-C6H4OMe, p-C6H4Cl, p-C6H4F) have been performed under solvent-free conditions in the melt phase and generally yielded the ionic products [(η5-RC5H4)Fe(CO)2PR′3]I rather than the CO substituted products (η5-RC5H4)Fe(CO)(PR′3)I. The complexes have been characterised by IR, NMR and MS techniques. By...

Journal: :Organic letters 2000
D W Old M C Harris S L Buchwald

[equation--see text] The N-arylation of indoles, including a variety of substituted ones, has been carried out using bulky, electron-rich phosphines as the supporting ligand in combination with Pd(2)(dba)(3). Using this catalyst system, the efficient coupling of indole and a variety of substituted indoles with aryl iodides, bromides, chlorides, and triflates can be achieved.

Journal: :Organic & biomolecular chemistry 2011
Gabriella Buscemi Philip W Miller Steven Kealey Antony D Gee Nicholas J Long Jan Passchier Ramon Vilar

Palladium dimers with sterically hindered phosphines have been shown to be excellent pre-catalysts for the aminocarbonylation of aryl halides to yield amides and one of them has been successfully employed as a pre-catalyst for the synthesis of (11)C-radiolabelled amides for PET imaging.

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