4696-27-9Relevant academic research and scientific papers
Supported imidazolylphosphine catalysts for highly (E)-selective alkene isomerization
Erdogan, Gulin,Grotjahn, Douglas B.
supporting information, p. 2818 - 2821 (2014/06/23)
For fine chemical synthesis, immobilized catalysts offer little advantage if they produce a product mixture that must be separated. Selective isomerization of terminal olefins is achieved by heterogenized bifunctional catalysts. Outstanding and consistent (E)-selectivity (>99%) even in cases where (E) and (Z) isomers are of comparable stability, combined with modest catalyst loadings (1 to 2 mol %), set these catalysts apart from previously reported systems. Ease of catalyst removal and high geometric selectivity avoid tedious purifications.
Stereoselective alkene isomerization over one position
Larsen, Casey R.,Grotjahn, Douglas B.
supporting information; experimental part, p. 10357 - 10360 (2012/08/08)
Although controlling both the position of the double bond and E:Z selectivity in alkene isomerization is difficult, 1 is a very efficient catalyst for selective mono-isomerization of a variety of multifunctional alkenes to afford >99.5% E-products. Many reactions are complete within 10 min at room temperature. Even sensitive enols and enamides susceptible to further reaction can be generated. Catalyst loadings in the 0.01-0.1 mol% range can be employed. E-to-Z isomerization of the product from diallyl ether was only -6 times as fast as its formation, showing the extremely high kinetic selectivity of 1.
Mild and selective deuteration and isomerization of alkenes by a bifunctional catalyst and deuterium oxide
Erdogan, Guelin,Grotjahn, Douglas B.
body text, p. 10354 - 10355 (2009/12/08)
(Figure Presented) H/D exchange is achieved at allylic positions of alkenes using D2O in acetone and alkene isomerization catalyst 1, which features a bifunctional imidazolylphosphine. The basic nitrogen of the latter is thought to deprotonate an alkene substrate coordinated to the CpRu center; at this stage the protonated nitrogen could undergo H/D exchange with deuterium oxide. An exceptional degree of deuteration is achieved at positions accessible to isomerization, with a high degree of control. Using biphasic settings one can literally wash out reactive protons on the substrate without using organic solvents.
Extensive isomerization of alkenes using a bifunctional catalyst: An alkene zipper
Grotjahn, Douglas B.,Larsen, Casey R.,Gustafson, Jeffery L.,Nair, Reji,Sharma, Abhinandini
, p. 9592 - 9593 (2008/03/11)
Catalyzed movement of alkene double bonds up to 30 positions has been accomplished using a catalyst featuring a cationic CpRu fragment and bifunctional imidazolylphosphine. The basic nitrogen of the latter is thought to deprotonate coordinated alkene intermediates reversibly, facilitating isomerization between terminal and (E)-alkenes and accelerating conversions by factors of up to 1 × 104. Copyright
Tumor inhibiting saccharide conjugates
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, (2008/06/13)
The invention relates to a method for the preparation of glycoconjugates of phosphorus amides with the general formula STR1 where the connection of the sugar with the phosphoric acid amide mustard residue, and the ifosfamide mustard residue, respectively, occurs preferably in the 1-position, and where R1 and R2 ; which can be the same or different, denote hydrogen, lower C1 -C4 alkyl or C1 -C6 haloalkyl and where as sugar there can be present mono-, di-, or polysaccharides in all existing isomeric and enantiomeric forms, wherein in a known way protected brominated sugars are conjugated with the respective phosphorus compounds, and freed of the protective residues, and to the use of said compounds as anti-tumour drugs.
THE DIPROPENYL ETHERS: VIBRATIONAL AND 13C NMR SPECTRA
Hollein, Helen C.,Snyder, William H.
, p. 187 - 204 (2007/10/02)
The infrared vapor phase and solution spectra and the Raman liquid phase spectra as well as the 13C NMR absorption have been examined for the dipropenyl ether isomers, i.e. cis, cis (I), cis, trans (II) and trans, trans (III).Evidence based on double bond vibrational coupling, the simple nature of the spectra and the assignment of most of the fundamentals shows only one planar s-trans, s-trans conformations for each isomers.The strong double bond coupling probably indicates that substantial "through space" electron delocalization between the double bonds must be involved, and that this reduces or takes precedence over oxygen electron delocalization in the order I > II > III.The "cis effect" is explained by a dipolar interaction of β-methyl hydrogen with ether oxygen, which is absent in the trans-propenyl structures.
