The present invention discloses an aminothiol compound having a general formula I wherein R
1
-R
5
are substitutable ligands. Such compound can perform as a superior catalyst in an asymmetric addition reaction of organic metal compounds and aldehyde. According to the present invention, the aminothiol compound is needed only less than 0.02% based on main reactants to obtain enantioselectivity higher than 98% enantiomeric excess, whereby the asymmetric reactions can become very economic.
1
New β-amino thiols as efficient catalysts for highly enantioselective alkenylzinc addition to aldehydes
作者:Shi-Liang Tseng、Teng-Kuei Yang
DOI:10.1016/j.tetasy.2004.11.093
日期:2005.2
A series of new optically active beta-amino thiols and thiolacetates prepared from the simple natural amino acid, (S)-(-)-valine, were found to be effective catalysts for the enantioselective addition of alkenylzinc to alclehydes and thereby providing an efficient route for chiral (E)-allylic alcohols with ees of up to >99% in the presence of 7a (1 mol %). (C) 2005 Published by Elsevier Ltd.
Secondary and Tertiary Amino Ketones and Alcohols Derived from Desoxybenzoin and 1,2-Diphenylethanol.<sup>1</sup> Ring-Chain Tautomerism of the α-(β-Hydroxyethylamino) Ketones<sup>2</sup>
作者:Robert E. Lutz、James A. Freek、Robert S. Murphey
DOI:10.1021/ja01186a012
日期:1948.6
Isomeric Amino Alcohols from the Reaction of Styrene Oxide with Benzylamine
作者:Colin L. Browne、Robert E. Lutz
DOI:10.1021/jo50009a002
日期:1952.9
Photochemistry of Intramolecular Charge Transfer Excited States in Donor-Acceptor-Substituted Diamines
作者:Yingsheng Wang、Kirk S. Schanze
DOI:10.1021/j100018a019
日期:1995.5
The photochemistry and photophysics of 1,2-diamines C(5)H(10)NCHPhCHPhNHC(6)H(4)R (1, R = CN, and 2, R = 4-pyridyl) have been examined. These compounds display a strong absorption band in the near-UV which is due to intramolecular charge transfer from the secondary amine group to the 4-cyanophenyl or (4-pyridyl)phenyl acceptor unit. Photoexcitation into this absorption band leads to moderately intense fluorescence from the (1)LE state of the charge transfer chromophore and to homolytic bond fragmentation across the 1,2 C-C bond with moderate quantum efficiency. Detailed photochemical and photophysical studies reveal that the bond fragmentation reaction ensues from a second intramolecular charge transfer excited state (denoted (CT)-C-1) which is based on electron transfer from the tertiary piperidine nitrogen to the 4-cyanophenyl or (4-pyridyl)phenyl unit. Photochemical product analysis reveals that erythro --> three (or three --> erythro) isomerization occurs under both argon-degassed and air-saturated conditions. This observation indicates that recombination of the radicals formed by bond fragmentation occurs, both within the geminate pair and between free radicals that have escaped the solvent cage. Analysis of fluorescence, transient absorption, and steady-state photochemical kinetics data indicates that (1) internal conversion from the (1)LE state to the (CT)-C-1 state by intramolecular electron transfer occurs with k greater than or equal to 10(9) s(-1) in all of the diamines; (2) bond fragmentation within the (CT)-C-1 state occurs with k greater than or equal to 10(8) s(-1) in each of the diamines: (3) bond fragmentation may be faster in erythro-1 than in threo-1.