Palladium(II) catalyzed allylic C-H alkylation reactions
type: CreativeWork
description: The selective formation of new carbon-carbon bonds is a central challenge for organic synthesis; organic molecules are based on carbon scaffolds which must be assembled from simple building blocks. Since Kolbe performed the first organic C-C bond forming reaction in his synthesis of acetic acid in 1845, the growth of organic synthesis has witnessed the proliferation of methods to forge C-C bonds. A recurring theme among these methods is the use of pre-installed, oxidized “functional groups” to enable and control the bond forming reaction. For the past 50 years, however, C-H activation has beckoned to chemists as the synthetic “way of the future.” Rather than relying upon a functional group, C-H activation promises the direct conversion of the inert, ubiquitous C-H bond to the desired C-C bond. This strategy has inspired tremendous excitement and speculation, but only recently has it begun to be reduced to practice in synthetically useful reactions. This work describes the discovery of the first palladium(II)-catalyzed allylic C-H alkylation reaction. Allylic alkylation has long been performed by palladium(0) catalysis with allylic oxygenate starting materials. In contrast, this method proceeds directly from the readily accessible, chemically robust a-olefin moiety. The development of such a reaction was impeded by the inherent incompatibility of the various steps of the putative catalytic cycle. In order to achieve catalytic turnover, an electrophilic C-H cleavage, a nucleophilic functionalization, and an oxidative Pd(II) regeneration step would all have to operate simultaneously. This series of interlocking compatibility challenges was unraveled with the aid of stoichiometric model studies and mechanistic insights gleaned from previous allylic C-H functionalization reactions. Ultimately, a catalytic allylic C-H alkylation reaction was discovered. The original allylic C-H alkylation reaction had an olefin scope limited to allylarene substrates. These substrates coul…
abstract: The selective formation of new carbon-carbon bonds is a central challenge for organic synthesis; organic molecules are based on carbon scaffolds which must be assembled from simple building blocks. Since Kolbe performed the first organic C-C bond forming reaction in his synthesis of acetic acid in 1845, the growth of organic synthesis has witnessed the proliferation of methods to forge C-C bonds. A recurring theme among these methods is the use of pre-installed, oxidized “functional groups” to enable and control the bond forming reaction. For the past 50 years, however, C-H activation has beckoned to chemists as the synthetic “way of the future.” Rather than relying upon a functional group, C-H activation promises the direct conversion of the inert, ubiquitous C-H bond to the desired C-C bond. This strategy has inspired tremendous excitement and speculation, but only recently has it begun to be reduced to practice in synthetically useful reactions. This work describes the discovery of the first palladium(II)-catalyzed allylic C-H alkylation reaction. Allylic alkylation has long been performed by palladium(0) catalysis with allylic oxygenate starting materials. In contrast, this method proceeds directly from the readily accessible, chemically robust a-olefin moiety. The development of such a reaction was impeded by the inherent incompatibility of the various steps of the putative catalytic cycle. In order to achieve catalytic turnover, an electrophilic C-H cleavage, a nucleophilic functionalization, and an oxidative Pd(II) regeneration step would all have to operate simultaneously. This series of interlocking compatibility challenges was unraveled with the aid of stoichiometric model studies and mechanistic insights gleaned from previous allylic C-H functionalization reactions. Ultimately, a catalytic allylic C-H alkylation reaction was discovered. The original allylic C-H alkylation reaction had an olefin scope limited to allylarene substrates. These substrates coul…
author: Young, Andrew
language: en
keywords: C-H activation, Allylic alkylation, Palladium catalysis, Sulfoxide ligands, Organometallic chemistry
date published: 2013-02-03T19:18:00Z
date modified: 2026-07-22T22:25:31Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/42164