84127-04-8Relevant articles and documents
Hydrogen/Halogen Exchange of Phosphines for the Rapid Formation of Cyclopolyphosphines
Barrett, Adam N.,Woof, Callum R.,Goult, Christopher A.,Gasperini, Danila,Mahon, Mary F.,Webster, Ruth L.
supporting information, p. 16826 - 16833 (2021/11/04)
The hydrogen/halogen exchange of phosphines has been exploited to establish a truly useable substrate scope and straightforward methodology for the formation of cyclopolyphosphines. Starting from a single dichlorophosphine, a sacrificial proton "donor phosphine"makes the rapid, mild synthesis of cyclopolyphosphines possible: reactions are complete within 10 min at room temperature. Novel (aryl)cyclopentaphosphines (ArP)5 have been formed in good conversion, with the crystal structures presented. The use of catalytic quantities of iron(III) acetylacetonate provides significant improvements in conversion in the context of diphosphine (Ar2P)2 and alkyl-substituted cyclotetra- or cyclopentaphosphine ((AlkylP)n, where n = 4 or 5) formation. Both iron-free and iron-mediated reactions show high levels of selectivity for one specific ring size. Finally, investigations into the reactivity of Fe(acac)3 suggest that the iron species is acting as a sink for the hydrochloric acid byproduct of the reaction.
Tailored Cobalt-Catalysts for Reductive Alkylation of Anilines with Carboxylic Acids under Mild Conditions
Liu, Weiping,Sahoo, Basudev,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
, p. 11673 - 11677 (2018/09/10)
The first cobalt-catalyzed hydrogenative N-methylation and alkylation of amines with readily available carboxylic acid feedstocks as alkylating agents and H2 as ideal reductant is described. Combination of tailor-made triphos ligands with cobalt(II) tetrafluoroborate significantly improved the efficiency, thus promoting the reaction under milder conditions. This novel protocol allows for a broad substrate scope with good functional group tolerance, even in the presence of reducible alkenes, esters, and amides.
Copper-catalyzed C–P cross-coupling of secondary phosphines with (hetero)aromatic bromide
Li, Chun-Jing,Lü, Jing,Zhang, Zhi-Xun,Zhou, Kun,Li, Yan,Qi, Guang-Hui
, p. 4547 - 4562 (2018/04/20)
A novel and convenient approach to the synthesis of various tertiary phosphines via a copper-catalyzed cross-coupling of (hetero)aromatic bromide with secondary phosphines has been developed. The reaction employs cheap copper as the catalyst, 2,6-bis(N-methylaminomethyl)pyridine (L4) as a perfect ligand and KOtBu as a base; all reactions are carried out under argon atmosphere. A variety of sterically hindered and/or functionalized substrates were found to react under these reaction conditions to provide products in good to excellent yields. Moreover, ten new tertiary phosphines were first reported in this process.