Photochemical activity of a key donor–acceptor complex can drive stereoselective catalytic α-alkylation of aldehydes
作者:Elena Arceo、Igor D. Jurberg、Ana Álvarez-Fernández、Paolo Melchiorre
DOI:10.1038/nchem.1727
日期:2013.9
unique mechanism of catalysis is proposed, wherein the catalyst is involved actively in both the photochemical activation of the substrates (by inducing the transient formation of chiral electrondonor–acceptorcomplexes) and the stereoselectivity-defining event. We use this approach to enable transformations that are extremely difficult under thermal conditions, such as the asymmetric α-alkylation of
Visible-Light-Promoted Stereoselective Alkylation by Combining Heterogeneous Photocatalysis with Organocatalysis
作者:Maria Cherevatskaya、Matthias Neumann、Stefan Füldner、Christoph Harlander、Susanne Kümmel、Stephan Dankesreiter、Arno Pfitzner、Kirsten Zeitler、Burkhard König
DOI:10.1002/anie.201108721
日期:2012.4.23
Dream team: Heterogeneous inorganic semiconductors and chiral organocatalysts team up for the stereoselective photocatalytic formation of carbon–carbon bonds. However, the connection between the organic and inorganic catalysts should not be too tight: Covalent immobilization inactivates the system.
Enantioselective α-Benzylation of Aldehydes via Photoredox Organocatalysis
作者:Hui-Wen Shih、Mark N. Vander Wal、Rebecca L. Grange、David W. C. MacMillan
DOI:10.1021/ja106593m
日期:2010.10.6
The first enantioselective aldehydeα-benzylation using electron-deficient aryl and heteroaryl substrates has been accomplished. The productive merger of a chiral imidazolidinone organocatalyst and a commercially available iridium photoredox catalyst in the presence of household fluorescent light directly affords the desired homobenzylic stereogenicity in good to excellent yield and enantioselectivity