94199-20-9Relevant academic research and scientific papers
Zirconium cation coordination in the borohydride-mediated synthesis of β-hydroxy-N-alkoxylamines
Williams, David R,Benbow, John W,Sattleberg, Thomas R,Ihle, David C
, p. 8597 - 8601 (2007/10/03)
Hydride reductions of oxime ethers to hydroxylamine derivatives are facilitated by the participation of neighboring hydroxyl groups. Precomplexation with zirconium cation in ether-methylene chloride solutions is effective for selective C=N bond reduction. The course for stereochemical control is dictated by Lewis acid coordination complexes of E- and Z-oximino ethers which lead to the preferred diastereofacial delivery of external hydride.
Asymmetric Diels-Alder reactions of enantiopure 1-methoxy-3-(phenyl-2- hydroxyethylsulfinyl)-1,3-butadienes
Aversa,Bonaccorsi,Giannetto,Jones
, p. 805 - 808 (2007/10/02)
Enantiopure 1-methoxy-3-(1-phenyl- and 2-phenyl-2-hydroxyethylsulfinyl)- 1,3-butadienes were prepared from ethyl mandelate. Diels-Alder reactions with methyl acrylate proceeded with complete regioselectivity and high diastereoselectivity.
Enantioselective Protonation of Samarium Enolates by a C2-Symmetric Chiral Diol
Takeuchi, Seiji,Ohira, Akiko,Miyoshi, Norikazu,Mashio, Hajime,Ohgo, Yoshiaki
, p. 1763 - 1780 (2007/10/02)
High enantioselectivity (up to 97percentee) have been achieved in the protonation of samarium enolates which were generated by SmI2-mediated cross-coupling reaction between unsymmetrical dialkylketene and allyl iodide, using, using a C2-symmetr
Recognition by New Symmetrically Substituted Chiral Diphenyl- and Di-tert-butylpyridino-18-crown-6 and Asymmetrically Substituted Chiral Dimethylpyridino-18-crown-6 Ligands of the Enantiomers of Various Organic Ammonium Perchlorates
Huszthy, Peter,Bradshaw, Jerald S.,Zhu, Cheng Y.,Izatt, Reed M.,Lifson, Shneior
, p. 3330 - 3336 (2007/10/02)
Three new chiral pyridino-18-crown-6 ligands have been prepared.These ligands contain either two phenyl, two tert-butyl, or two methyl substituents on chiral macroring carbon atoms.The chiral di-tert-butyl-substituted diester crown analogue was also prepared.The starting chiral di-tert-butyl-substituted tetraethylene glycol needed to prepare the two di-tert-butyl-substituted crowns was obtained from chiral tert-butyl-1,2-ethanediol, which was resolved from its bis(hydrogen phthalate) brucine salt.A high degree of chiral recognition in CD2Cl2 of the enantiomers of ammonium perchlorate (NapEt) was shown by the diphenyl- and di-tert-butyl-substituted crowns as measured by differences in the free energy of avtivation (ΔGc*) values determined by temperature dependent 1H NMR spectroscopy.The diphenyl- and di-tert-butyl-substituted crowns also exhibited high chiral recognition for the enantiomers of NapEt and other chiral organic ammonium salts in methanol and methanol-chloroform mixtures as shown by a large difference in the log K values determined by a direct 1H NMR technique.
Asymmetric Radical Reaction in the Coordination Sphere. 2. Asymmetric Addition of Alkane- and Arenesulfonyl Chlorides to Olefins Catalyzed by a Ruthenium(II)-Phosphine Complex with Chiral Ligands
Kameyama, Masayuki,Kamigata, Nobumasa,Kobayashi, Michio
, p. 3312 - 3316 (2007/10/02)
The addition of arenesulfonyl chlorides to styrene in the presence of a catalytic amount of a ruthenium(II) complex with chiral phosphine ligands, Ru2Cl43 or Ru2Cl43, proceeds under mild conditions to give optically active 1:1 adducts,
The Preparation of New Chiral Diphenyl-Substituted Macrocyclic Polyether-Diester Compounds and their Enantiomeric Recognition of Chiral Organic Ammonium Salts
Bradshaw, Jerald S.,Thompson, Patricia K.,Izatt, Reed M.,Morin, Frederick G.,Grant, David M.
, p. 897 - 901 (2007/10/02)
A series of chiral diphenyl-substituted macrocyclic polyether-diester ligands have been prepared from the chiral diphenyl-substituted tetraethylene glycol.Enantiomeric recognition by the chiral diphenyl-sunstituted pyridino-diester-18-crown-6 compound (7)
