Light-Driven Organocatalysis Using Inexpensive, Nontoxic Bi<sub>2</sub>O<sub>3</sub>as the Photocatalyst
作者:Paola Riente、Alba Matas Adams、Josep Albero、Emilio Palomares、Miquel A. Pericàs
DOI:10.1002/anie.201405118
日期:2014.9.1
enantioselective catalytic processes that make use of sunlight as the energy source and nontoxic, affordable materials as catalysts represents one of the new and rapidly evolving areas in chemical research. The direct asymmetric α‐alkylation of aldehydes with α‐bromocarbonyl compounds can be successfully achieved by combining bismuth‐based materials as low‐band‐gap photocatalysts with the second‐generation MacMillan
Mechanism of the Stereoselective α-Alkylation of Aldehydes Driven by the Photochemical Activity of Enamines
作者:Ana Bahamonde、Paolo Melchiorre
DOI:10.1021/jacs.6b04871
日期:2016.6.29
Herein we describe our efforts to elucidate the key mechanistic aspects of the previously reported enantioselective photochemical α-alkylation of aldehydes with electron-poor organic halides. The chemistry exploits the potential of chiral enamines, key organocatalytic intermediates in thermal asymmetric processes, to directly participate in the photoexcitation of substrates either by forming a photoactive
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