trans-1-Sulfonylamino-2-isoborneolsulfonylaminocyclohexane Derivatives: Excellent Chiral Ligands for the Catalytic Enantioselective Addition of Organozinc Reagents to Ketones
作者:Vicente J. Forrat、Oscar Prieto、Diego J. Ramón、Miguel Yus
DOI:10.1002/chem.200501397
日期:2006.5.24
The catalytic enantioselectiveaddition of different organozinc reagents (such as alkyl and aryl derivatives or in situ generated aryl, allyl alkenyl, and alkynyl derivatives obtained through different transmetallation processes) to simple ketones has been accomplished by using titanium tetraisopropoxide and chiral ligands derived from substituted trans-1-sulfonylamino-2-isoborneolsulfonylaminocyclohexane
Synthesis, structure and chiroptical study of chiral macrocyclic imine nickel(ii) coordination compounds derived from camphor
作者:Tao Wu、Cheng-Hui Li、Yi-Zhi Li、Zhao-Gui Zhang、Xiao-Zeng You
DOI:10.1039/b923326a
日期:——
A couple of enantiomers of novel chiralmacrocyclic imines based on R/S-camphor were asymmetrically synthesized. Through the chiralmacrocyclic ligands, enantiomers of nickel(II) coordination compounds were obtained. The chirality of the ligand was transferred to the nickel atom upon coordination, leading to predetermined configuration. The chiral ligands and corresponding nickel coordination compounds
Titanium-promoted enantioselective diethylzinc addition to benzaldehyde in the presence of C2-symmetrical bis(camphorsulfonamide) ligands
作者:Tomasz Bauer、Joanna Gajewiak
DOI:10.1016/j.tet.2003.10.030
日期:2003.12
The synthesis of several C2-symmetric bissulfonamides is described, starting from camphorsulfonyl chloride and various aromatic as well as aliphatic diamines. These compounds have been used as ligands for titanium tetraisopropoxide promoted diethylzinc addition to benzaldehyde. The best enantiomeric excess obtained in this study was 67%. The stereochemical outcome of the reaction is highly influenced
Vibrational and electronic circular dichroism monitoring of copper(II) coordination with a chiral ligand
作者:Tao Wu、Xiao-Peng Zhang、Cheng-Hui Li、Petr Bouř、Yi-Zhi Li、Xiao-Zeng You
DOI:10.1002/chir.22010
日期:2012.6
macrocyclic imine ligands derived from R‐/S‐camphor were asymmetrically synthesized and characterized with the aid of chiroptical spectroscopies. Crystal structures of both enantiomers were determined by single crystal X‐ray diffraction analysis. Circular dichroism (CD) spectra were analyzed using a simplified exciton model as well as quantum chemical computations. The absoluteconfiguration of the copper(II)