68850-07-7Relevant articles and documents
Photo-Arbuzov rearrangements of cyclic phosphite systems
Landis, Margaret S,Turro, Nicholas J,Bhanthumnavin, Worawan,Bentrude, Wesley G
, p. 239 - 246 (2002)
The direct UV irradiation of cyclic phosphites 1-4 was carried out in argon-saturated solvents. In all cases examined, the rearranged, ring-contracted Photo-Arbuzov phosphonate was the major product formed with isolated yields ranging from 40 to 50%. Thes
Optical resolution of C2-symmetric racemic 1,4-diols with o-xylylene structure by chiral resolving agent (S)-ALBO-V
Asami, Masatoshi,Zhong, Lvling,Sekiguchi, Naoki,Yamada, Kumiko,Hiwatashi, Yuya,Taniguchi, Toshiro,Hosoda, Naoya,Ito, Suguru
supporting information, p. 966 - 968 (2015/09/01)
Optical resolution of C2-symmetric racemic 1,4-diols, 1,2-bis(1-hydroxyalkyl)benzene, was examined using (S)-5-allyl-2-oxabicyclo[3.3.0]octene ((S)-ALBO-V) as chiral resolving agent. Diastereomeric acetals obtained from the 1,4-diols with (S)-A
Simple Aza -conjugate addition methodology for the synthesis of isoindole nitrones and 3,4-dihydroisoquinoline nitrones
Peacock, Lucy R.,Chapman, Robert S. L.,Sedgwick, Adam C.,Bull, Steven D.,Mahon, Mary F.,Amans, Dominique
supporting information, p. 994 - 997 (2015/03/18)
Aryl-aldehydes containing ortho-substituted α,β-unsaturated carboxylic acid derivatives react with hydroxylamine to afford reactive N-hydroxy-carbinolamine intermediates that undergo intramolecular aza-conjugate addition reactions to afford isoindole nitrones and 3,4-dihydroisoquinoline nitrones in good yield. Conditions have been developed to reduce these isoindole nitrones to their corresponding hydroxylamine, enamine, and amine derivatives. Isoindole nitrones react with dimethyl acetylenedicarboxylate (DMAD) via a [4 + 2]-cycloaddition/deamination pathway to afford substituted naphthalene derivatives, while 3,4-dihydroisoquinoline nitrones react with DMAD via a [1,3]-dipolar cycloaddition pathway to afford tricyclic heteroarenes.
Synthesis of α,β-unsaturated dioxanes, dioxolanes and dioxepanes by trans-acetalisation of dimethylacetals with meso or C 2-symmetrical 1,2-, 1,3- and 1,4-diols
Lemiègre, Lo?c,Lesetre, Fleur,Combret, Jean-Claude,Maddaluno, Jacques
, p. 415 - 427 (2007/10/03)
Several o-dibenzylic diols were prepared reacting organometallics with o-phthalaldehyde at room temperature in ether. The identity of the meso and C2-symmetrical (D,L) isomers as well as their ratio were determined by chiral gas chromatography. The meso and C2 (racemic) stereoisomeric diols were easily separated by flash chromatography on silica gel. A set of 18 α,β-unsaturated acetals were then prepared reacting those, as well as commercially available 1,2, 1,3 and 1,4 diols, with the corresponding methylacetals in acidic medium. A trans-acetalisation procedure adapted to the cases of fragile allylic alcohols or unfavorable 1,6 diols-derived dioxonanes based on a Dean-Stark trapping of methanol was also employed.
NEW CHIRAL DIOLS, THEIR MANUFACTURE AND LIGANDS AND CATALYSTS DERIVED THEREFROM
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Page 26, (2008/06/13)
The present invention relates to a method for the preparation of C2-symmetric 1,4-diols of the formula IVA or IVB, wherein ring A, R1 and R2 have the meanings given in the specification, that makes use of the metallation of pure enantiomers of α-(aryl or heteroaryl)-α-substituted alkanol compounds or the use of said alkanol compounds in the preparation of said mmetric 1,4-diols; novel C2--symmetric 1,4-diols in enantiomerically pure form; and methods of use or their use in the synthesis of chiral ligands which find use to produce catalysts for a variety of asymmetric transformations such as hydrogenations.
Asymmetric synthesis catalyzed by transition metal complexes with new chiral ligands
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, (2008/06/13)
A chiral ligand having the following structure: STR1 wherein AR is any aromatic and/or ring structure, and R is selected from the group consisting of aryl, oxygenated aryl, alkyl, oxygenated alkyl, AR, oxygenated AR and combinations thereof.
Chelating ligands and catalysts and processes employing the same
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, (2008/06/13)
A hydroformylation process including contacting hydroformylation stock in a reaction zone at a temperature of from about 20° C. to about 250° C. and a pressure of from about 15 psig to about 800 psig with hydrogen and carbon monoxide wherein the catalyst
Chemoselective Addition of Organotitanium Reagents to Carbonyl Compounds
Reetz, Manfred T.,Westermann, Juergen,Steinbach, Rainer,Wenderoth, Bernd,Peter, Roland,et al.
, p. 1421 - 1440 (2007/10/02)
The conversion of classical carbanions such as RMgX, RLi, or deprotonated nitriles, sulfones, and carboxylic esters into titanium analogs results in reagents which add chemoselectively to carbonyl compounds in the presence of other functional groups.The standard titanating agent is chlorotriisopropoxytitanium (1).Grignard-type reactions and aldol additions are aldehyde-selective in the presence of ketones.Other functional groups such as alkyl and aryl halides, esters, amides as well as nitro and cyano moieties are tolerated.Discrimination between two aldehydes or two ketones is also possible.Replacing alkoxy ligands by methyl groups at titanium increases reactivity dramatically, relative rates increasing in the series CH3Ti(OCHMe2)3 (CH3)2Ti(OCHMe2)2 (CH3)4Ti.The latter reagent and its zirconium analog methylate sterically hindered and/or enolizable ketones which normally fail to undergo Grignard reactions.The ate complex H2C=CHCH2Ti(OCHMe2)4MgCl (63) is aldehyde-selective, while the amino analog H2C=CHCH2Ti(NMe2)4MgCl (64) adds selectively to ketones in the presence of aldehydes.
