2848-01-3Relevant articles and documents
A Palladium-Free Sonogashira Coupling Protocol Employing an in Situ Prepared Copper/Chelating 1,2,3-Triazolylidene System
Tonis, Efstathios,Stein, Felix,Stamatopoulos, Ioannis K.,Stubbe, Jessica,Zarkadoulas, Athanasios,Sarkar, Biprajit,Vougioukalakis, Georgios C.
, p. 616 - 620 (2020/11/25)
A new, palladium-free Sonogashira coupling reaction protocol using a catalytic system that comprises a simple, cheap, widely available copper salt and a chelating 1,2,3-triazolylidene ligand precursor is reported. This protocol provides the desired coupling products in moderate to very good yields.
Rosuvastatin intermediate compound and preparation method and application thereof
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Paragraph 0030, (2017/08/29)
The invention relates to an intermediate compound for preparation of rosuvastatin calcium. A structure of the intermediate compound is shown as a formula (I), and the intermediate compound is stable and high in nucleophilicity and reaction activity. In addition, the invention further relates to a preparation process suitable for industrial production of rosuvastatin calcium. Due to adoption of the intermediate compound, a rosuvastatin calcium preparation method is mild in reaction condition, free of ultralow-temperature equipment, simple in aftertreatment and easy in operation, and intermediate product olefin which is an intermediate compound shown as a formula (III) is high in stereoselectivity and yield, high in product quality and high in economic benefit.
Cyclic decapeptide gramicidin S derivatives containing phosphines: Novel ligands for asymmetric catalysis
Guisado-Barrios, Gregorio,Mu?oz, Bianca K.,Kamer, Paul C. J.,Lastdrager, Bas,Van Der Marel, Gijs,Overhand, Mark,Vega-Vázquez, Marino,Martin-Pastor, Manuel
supporting information, p. 1973 - 1978 (2013/05/22)
The cyclic peptide gramicidin S was used as a rigid template to provide novel peptide-based bisphosphine ligands for transition metal catalysis. Two bisphosphine-coordinated Rh(i) complexes allowed asymmetric hydrogenation with 10-52% ee and the corresponding Pd(ii) analogues catalysed asymmetric allylic alkylation with 13-15% ee. The Royal Society of Chemistry 2013.
PREPARATION OF DIAZO AND DIAZONIUM COMPOUNDS
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Page/Page column 26, (2010/06/13)
A method for making diazo-compounds, diazonium salts thereof and other protected forms of these compounds. Diaz-compounds are prepared by reaction of a tertiary phosphine reagent carrying a reactive carbonyl group with an azide. The reaction can also generate an acyl triazene which can be converted thermally or by addition of base to form the diazo-compound or the acyl triazene can be isolated. The method is particularly useful for conversion of azides carrying one or more electron withdrawing groups to diazo-compounds. The method can be carried out in aqueous medium under mild conditions and is particularly useful for conversion of azido sugars to diazo-compound and diazonium salts thereof under physiological conditions. Tertiary phosphine reagents, particularly those that are water-soluble, and precursors for preparation of the reagents are provided.
Approaches to water-soluble phosphines. II. Free radical addition reactions of phenylphosphines
Heesche-Wagner, Kerstin,Mitchell, Terence N.
, p. 99 - 106 (2007/10/02)
Free radical additions of diphenylphosphine, phenylphosphine and ethylenebis(phenylphosphine) to the following species are described: alkynols, alkyne ethers, unsaturated carboxylic acids and esters and β-lactones.In a number of cases, these lead to water-soluble phosphines.NMR spectroscopic characterization of all new products has been carried out.Key words: Phosphine; Water soluble phosphines; Radical addition; Chirality
Reductive cleavage of the carbon-phosphorus bond with alkali metals. III Reactions of arylalkylphosphines
Doorn, Johannes A. van,Meijboom, Nico
, p. 170 - 177 (2007/10/02)
The reductive cleavage of phenylalkylphosphines Ph2PR, PhPR2 (R = Bu, iPr) with Na/NH3 is unselective; both phenyl and alkyl groups can be cleavaged and Birch reduction may occur.Reaction of Ph2tBuP gives a high yield of diphenylphosphide.Polar groups (CO2Na, SO3Na) at the ω position of primary alkyl groups may lead to an increase in selectivity; Birch reduction is suppressed and a functionalised secondary phosphide is obtained.From diarylbenzyl- and diarylallylphosphines, the benzyl and allyl groups are selectively removed; Ar2PH and ArRPH are formed in high yield after hydrolytic work-up unless the aryl group bears F, CF3 or (CH3)2N substituents.From the reaction mixture of Ph2PCH2Ph we have isolated 1,2-diphenylethane. 2-Methoxyphenyl and 2,6-dimethoxyphenyl groups are selectively removed from Ar2BuP, ArPhBuP and Ar2P(CH2)3PAr2, forming ArBuPH, PhBuPH and ArP(H)(CH2)3(H)PAr, respectively.A double-cleavage reaction of Ar2RP may occur in low yield. 2,6-(dimethoxyphenyl-dibutylphosphine gives dibutylphosphine in moderate yield.When compounds with a 2,6-dimethoxyphenyl moiety are allowed to react with Li/THF, removal of a methyl group leads to novel phosphinophenols.It is concluded that cleavage of alkyl groups R selectively occurs when R radical is relatively stable (tBu, PhCH2> iPr > Bu).
ADDITION OF DIPHENYLPHOSPHINE TO MALEIC ANHYDRIDE AND RELATED COMPOUNDS
Doorn, J. A. van,Wife, R. L.
, p. 253 - 260 (2007/10/02)
A Michael addition of secondary phosphines to activated olefins containing the ethenedione moiety such as maleic anhydride, maleic ester and dibenzoylethene leads to functionalised tertiary phosphines.Reactions of activated olefins which contain a carboxylic group do not lead to the expected products; instead, phosphonium salts are formed by a sequence of reactions.A hydrogen shift plays a crucial role both in the reaction that leads to the adduct and in the reaction that leads to the phosphonium salt.Phosphinosuccinic anhydrides and phosphinosuccinic esters can betransformed into the corresponding succinic acids.Decarboxylation of phosphinosuccinic acids leads to phosphinopropionic acids.
A Simple Synthesis and Some Synthetic Applications of Substituted Phosphide and Phosphinite Anions
Tsvetkov, E. N.,Bondarenko, N. A.,Malakhova, I. G.,Kabachnik, M. I.
, p. 198 - 208 (2007/10/02)
Based on data for the acidity relationship of phosphines and phosphinous acids and water in dimethyl sulfoxide and water, a simple method is reported for the generation of phosphide and phosphinite anions by the action of concentrated aqueous alkali on primary and secondary phosphines as well as phosphinous acids in dimethyl sulfoxide or other dipolar aprotic solvents.Alkylation of the anion yields secondary and tertiary phosphines, polyphosphines, functionally substituted phosphines as well as similarly substituted phosphine oxides.Phosphinous acids have beenalkylated in various solvents in two-phase systems containing concentrated aqueous alkali and tetrabutylammonium iodide as phase transfer catalyst.
