Tandem α-Alkylation/Asymmetric Transfer Hydrogenation of Acetophenones with Primary Alcohols
作者:Oleksandr O. Kovalenko、Helena Lundberg、Dennis Hübner、Hans Adolfsson
DOI:10.1002/ejoc.201403032
日期:2014.10
A tandem -alkylation/asymmetric transferhydrogenation of acetophenones with primary alcohols, mediated by a single ruthenium catalyst, is described. Under optimized reaction conditions and with use of [Ru(p-cymene)Cl-2](2) in combination with an amino acid hydroxyamide ligand, the chiral secondary alcohol products were isolated in moderate yields and in moderate to good enantiomeric excess (up to
An efficient catalyst for the asymmetric addition of organoaluminum reagents to aldehydes is presented. The system is based on a readily available binaphthyl derivative as a chiral ligand and an excess of titanium tetraisopropoxide. The asymmetric methylation, ethylation, and propylation of a wide variety of aromatic and aliphatic aldehydes proceeded with good yields and with high enantioselectivities in a simple one-pot procedure under mild conditions. (C) 2012 Elsevier Ltd. All rights reserved.
A relay catalysis strategy for enantioselective nickel-catalyzed migratory hydroarylation forming chiral α-aryl alkylboronates
Ligand-controlled reactivity plays an important role in transition-metal catalysis, enabling a vast number of efficient transformations to be discovered and developed. However, a single ligand is generally used to promote all steps of the catalytic cycle (e.g., oxidative addition, reductive elimination), a requirement that makes ligand design challenging and limits its generality, especially in relay