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Tandem Acid/Pd-Catalyzed Reductive Rearrangement of Glycol Derivatives.

ABSTRACT: 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 ?,?'-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.

SUBMITTER: Schmidt TA

PROVIDER: S-EPMC7154628 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

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Tandem Acid/Pd-Catalyzed Reductive Rearrangement of Glycol Derivatives.

Schmidt Tanno A TA Ciszek Benjamin B Kathe Prasad P Fleischer Ivana I

Chemistry (Weinheim an der Bergstrasse, Germany) 20200304 16

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 requ ...[more]

PMID: 31951298

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