22859-83-2Relevant articles and documents
Tandem Acid/Pd-Catalyzed Reductive Rearrangement of Glycol Derivatives
Ciszek, Benjamin,Fleischer, Ivana,Kathe, Prasad,Schmidt, Tanno A.
supporting information, p. 3641 - 3646 (2020/03/25)
Herein, we describe the acid/Pd-tandem-catalyzed transformation of glycol derivatives into terminal formic esters. Mechanistic investigations show that the substrate undergoes rearrangement to an aldehyde under [1,2] hydrogen migration and cleavage of an oxygen-based leaving group. The leaving group is trapped as its formic ester, and the aldehyde is reduced and subsequently esterified to a formate. Whereas the rearrangement to the aldehyde is catalyzed by sulfonic acids, the reduction step requires a unique catalyst system comprising a PdII or Pd0 precursor in loadings as low as 0.75 mol % and α,α′-bis(di-tert-butylphosphino)-o-xylene as ligand. The reduction step makes use of formic acid as an easy-to-handle transfer reductant. The substrate scope of the transformation encompasses both aromatic and aliphatic substrates and a variety of leaving groups.
Synthesis and C-alkylation of hindered aldehyde enamines
Hodgson, David M.,Bray, Christopher D.,Kindon, Nicholas D.,Reynolds, Nigel J.,Coote, Steven J.,Um, Joann M.,Houk
body text, p. 1019 - 1028 (2009/07/04)
A new reactivity mode of hindered lithium amides with terminal epoxides is described whereby aldehyde enamines are produced via a previously unrecognized reaction pathway. Some of these aldehyde enamines display unprecedented C-alkylation reactivity toward unactivated primary and secondary alkyl halides. For comparison, the reactivity of aldehyde enamines synthesized via a traditional condensation method was examined. C-rather than N-alkylation was the dominant reaction pathway found with a range of electrophiles, making this route to α-alkylated aldehydes more synthetically useful than previously reported.
