نتایج جستجو برای: phosphines

تعداد نتایج: 579  

Journal: :Dalton transactions 2011
Rafael Ballesteros-Garrido Laurence Bonnafoux Fernando Blanco Rafael Ballesteros Frédéric R Leroux Belén Abarca Françoise Colobert Ibon Alkorta José Elguero

A series of new triazolopyridine-based phosphines has been prepared. These compounds revealed unexpected spectroscopic patterns. In particular, the NMR spectra are highly dependent on the relative conformational preference of the phosphine substituent at C7. Here, we report on their complete NMR analysis, X-ray structures and DFT calculations that confirm the particular arrangement of the phosp...

Journal: :Dalton transactions 2013
Daniele Anselmo Rafael Gramage-Doria Tatiana Besset Martha V Escárcega-Bobadilla Giovanni Salassa Eduardo C Escudero-Adán Marta Martínez Belmonte Eddy Martin Joost N H Reek Arjan W Kleij

The use of the commercially available, bifunctional phosphine 1,3,5-triaza-7-phosphaadamantane (abbreviated as PN3) in conjunction with a series of Zn(salphen) complexes leads to sterically encumbered phosphine ligands as a result of (reversible) coordinative Zn-N interactions. The solid state and solution phase behaviour of these supramolecular ligand systems have been investigated in detail a...

Journal: :Chemical communications 2005
Makeba B Murphy-Jolly Lesley C Lewis Andrew J M Caffyn

Tris(perfluoroalkyl)phosphines, of interest as tunable alternatives to the carbon monoxide ligand, can be synthesised by the nucleophile mediated reaction of perfluoroalkyltrimethylsilanes with triphenylphosphite; the method can be extended to diphosphines.

Journal: :Chemical communications 2016
A F Fearnley J An M Jackson P Lindovska R M Denton

We report a synthesis method for the construction of quaternary aryl phoshonium salts at ambient temperature. The regiospecific reaction involves the coupling of phosphines with aryl radicals derived from diaryliodonium salts under photoredox conditions.

Journal: :Dalton transactions 2010
Robin J Blagg Neil G Connelly Mairi F Haddow Alex Hamilton Matteo Lusi A Guy Orpen Benjamin M Ridgway

The heteroscorpionate ligands [HB(taz)(2)(pz(R))](-) (pz(R) = pz, pz(Me2), pz(Ph)) and [HB(taz)(pz)(2)](-), synthesised from the appropriate potassium hydrotris(pyrazolyl)borate salt and 4-ethyl-3-methyl-5-thioxo-1,2,4-triazole (Htaz), react with [{Rh(cod)(μ-Cl)}(2)] to give [Rh(cod)Tx] {Tx = HB(taz)(2)(pz), HB(taz)(2)(pz(Me2)), HB(taz)(2)(pz(Ph)), HB(taz)(pz)(2)}; the heteroscorpionate rhodabo...

Journal: :Chemical communications 2015
Roman Dobrovetsky Katsuhiko Takeuchi Douglas W Stephan

The stoichiometric reaction of trityl cation with two equivalents of Ph2PH affords the phosphine stabilized phosphenium salt [Ph2(H)PPPh2][B(C6F5)4] via hydride abstraction, while catalytic amounts of B(p-HC6F4)3 effects catalytic phosphine dehydrocoupling with the liberation of H2. This reaction is accelerated by the presence of olefin or imine, effecting concurrent hydrogenation.

Journal: :Chemistry 2015
Andrew K King Antoine Buchard Mary F Mahon Ruth L Webster

Catalytic dehydrocoupling of primary and secondary phosphines has been achieved for the first time using an iron pre-catalyst. The reaction proceeds under mild reaction conditions and is successful with a range of diarylphosphines. A proton acceptor is not needed for the transformation to take place, but addition of 1-hexene does allow for turnover at 50 °C. The catalytic system developed also ...

Journal: :Chemical communications 2006
Rosenildo Corrêa da Costa J A Gladysz

Reactions of the bis(pyridine) complex (H2IMes)(Py)2(Cl)2Ru(=CHPh) and fluorous phosphines P(CH2CH2R(fn))3 (n = a, 6; b, 8; c, 10; R(fn) = (CF2)(n-1)CF3) give (H2IMes)(P(CH2CH2R(fn))3)(Cl)2Ru(=CHPh) (2a-c, 64-73%), which are analogs of Grubbs' second generation catalyst and effective alkene metathesis catalysts under organic monophasic and fluorous/organic biphasic conditions. The latter give r...

Journal: :The Journal of organic chemistry 1997
Zhaogen Chen Qiongzhong Jiang Guoxin Zhu Dengming Xiao Ping Cao Cheng Guo Xumu Zhang

Design and synthesis of chiral phosphines have played a significant role in the development of transition metal catalyzed asymmetric reactions.1 Many excellent chiral bidentate phosphines such as DIPAMP,2 DIOP,3 Chiraphos,4 and BINAP5 have been developed for a variety of catalytic reactions. Recent additions to this family of ligands include the Duphos and BPE species of Burk and co-workers.6 T...

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