Praseodymium-Induced Pinacol Formation

Abstract

In an attempt to regenerate Ti(0) from TiO x for possible application in a catalytic McMurry coupling reaction, a praseodymium-based pinacol reaction was uncovered. This reaction formed the two products 2,3-diphenyl-2,3-butanediol (3) and a,b-dimethyl-a-phenyl-b-[(trimethylsilyl)oxy]-benzene-ethanol (6) in a 1:3 ratio.

A Rare Earth Metal Catalyzed Aerobic Dehydrogenation of N-Heterocycles

“…Imamoto et al discovered that a simple praseodymium chloride salt combined with lithium reagents could efficiently yield alcohols from carbonyl compounds under mild conditions . Priefer et al reported that the in situ formed reagents of Pr 0 /TMSCl induced carbon–carbon coupling of ketones to generate pinacols . Zhang et al studied the Barbier-type reaction with praseodymium reagents, which showed efficient insertion of the carbon–iodide bond of allyl iodide to yield the organometallic complex, reacting with ketones under mild conditions without any additives .…”

“…8 Priefer et al reported that the in situ formed reagents of Pr 0 /TMSCl induced carbon− carbon coupling of ketones to generate pinacols. 9 Zhang et al studied the Barbier-type reaction with praseodymium reagents, which showed efficient insertion of the carbon−iodide bond of allyl iodide to yield the organometallic complex, reacting with ketones under mild conditions without any additives. 10 In 2017, Pan et al discovered that Pr(OTf) 3 -catalyzed regioselective amination using azides could produce C3−Nsubstituted coumarins.…”

α-Regioselective Barbier Reaction of Carbonyl Compounds and Allyl Halides Mediated by Praseodymium

“…However, the use of zerovalent lanthaniod metals in Barbier reaction was still limited to Sm . To the best of our knowledge, only a few cases using praseodymium metal directly in organic synthesis have been reported . Very recently, our group became deeply interested in the application of lanthanide metals in organic synthesis .…”