Reversal of enantioselectivity using catalysts containing multiple stereogenic centres
摘要:
N-methylation of ligands with multiple stereogenic centres is shown to provide the product of the opposite configuration in significant enantiomeric excess (e.e), in the addition of diethylzinc to aldehydes. The catalysts possess stereogenic centres appended to a trans-1,2-cyclohexanediamine core. (C) 2001 Elsevier Science Ltd. All rights reserved.
Asymmetric synthesis using catalysts containing multiple stereogenic centres and a trans-1,2-diaminocyclohexane core; reversal of predominant enantioselectivity upon N-alkylation
作者:Alexander J.A. Cobb、Charles M. Marson
DOI:10.1016/j.tet.2004.11.030
日期:2005.1
N-Methylation of ligands containing a trans-1,2-diaminocyclohexane core and multiple stereogeniccentres is shown to provide the product of the opposite configuration in significant enantiomeric excess, in the addition of diethylzinc to aldehydes. Some of the ligands were effective in an asymmetric Michael addition.
Reversal of enantioselectivity using catalysts containing multiple stereogenic centres
作者:Alexander J.A. Cobb、Charles M. Marson
DOI:10.1016/s0957-4166(01)00290-7
日期:2001.7
N-methylation of ligands with multiple stereogenic centres is shown to provide the product of the opposite configuration in significant enantiomeric excess (e.e), in the addition of diethylzinc to aldehydes. The catalysts possess stereogenic centres appended to a trans-1,2-cyclohexanediamine core. (C) 2001 Elsevier Science Ltd. All rights reserved.
Metal Complexes of New, Chiral N<sub>2</sub>O<sub>2</sub> Tetradentate Ligands
作者:Ronald J. Cross、Louis J. Farrugia、Paul D. Newman、Robert D. Peacock、Diane Stirling
DOI:10.1021/ic980172l
日期:1999.3.1
groups, though the chiral ligands adopt a different stereochemistry in the two complexes. In 2, the absoluteconfiguration about the Cu(II) center is Delta, with the nitrogens possessing the S stereochemistry, whereas for the Ni(II) analogue, coordination gives the Lambda isomer with the R configuration at the stereogenic nitrogens. Addition of H(2)L1 or H(2)L2 to Mn(II) in basic methanol solution results