Reaction of aromatic aldehydes and ketones with ytterbium metal gives the corresponding pinacols in high yields. Cross-coupling reaction of benzophenone with other carbonyl compounds to produce unsymmetrical pinacols is also described.
Bis(tri-n-butylstannyl)benzopinacolate: Preparation and use as a mediator of intermolecular free radical reactions
作者:David J. Hart、Ramanarayanan Krishnamurthy、Lori M. Pook、Franklin L. Seely
DOI:10.1016/s0040-4039(00)61484-3
日期:1993.12
Bis(tri-n-butylstannyl)benzopinacolate (2) serves as a thermal source of tri-n-butylstannyl radicals and mediates intermolecular coupling of selected alkyl halides to O-benzylformaldoxime and electron deficient olefins. A free radical non-chain mechanism is proposed for these reactions.
Direct β-Functionalization of Cyclic Ketones with Aryl Ketones via the Merger of Photoredox and Organocatalysis
作者:Filip R. Petronijević、Manuel Nappi、David W. C. MacMillan
DOI:10.1021/ja410478a
日期:2013.12.11
The direct β-coupling of cyclic ketones with aryl ketones has been achieved via the synergistic combination of photoredoxcatalysis and organocatalysis. Diaryl oxymethyl or aryl-alkyl oxymethyl radicals, transiently generated via single-electron reduction of ketone precursors, readily merge with β-enaminyl radical species, generated by photon-induced enamine oxidation, to produce γ-hydroxyketone adducts