Browsing by Subject "Functionalization"

Now showing 1 - 3 of 3
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    Pd-catalyzed C(sp(3))-H functionalization/carbenoid insertion: all-carbon quaternary centers via multiple C-C bond formation
    (American Chemical Society, 2016-05-04) Gutierrez Bonet, Alvaro; Juliá Hernández, Francisco; Luis, Beatriz de; Martin, Ruben; Química Inorgánica
    A Pd-catalyzed C(sp3)-H functionalization/carbenoid insertion is described. The method allows for the rapid synthesis of bicyclic frameworks, generating all-carbon quaternary centers via multiple C–C bond-formations in a straightforward manner.
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    Remote carboxylation of halogenated aliphatic hydrocarbons with carbon dioxide
    (Nature Research, 2017-05-04) Juliá Hernández, Francisco; Moragas, Toni; Cornella, Josep; Martin, Ruben; Química Inorgánica
    Catalytic carbon-carbon bond-formation has allowed for the streamline of synthetic routes when assembling complex molecules. This is particularly important when incorporating saturated hydrocarbons, common motifs in petrochemicals and biologicallyrelevant molecules. However, cross-coupling methods involving alkyl electrophiles occur at specific and previously functionalised sites. Herein, we describe the discovery of a catalytic method capable of promoting carboxylation reactions at remote and unfunctionalised aliphatic sites under atmospheric pressure of CO2. The reaction occurs via selective migration of the catalyst along the hydrocarbon side-chain and operates with excellent regio- and chemoselectivity profile. Our results demonstrate that site-selectivity can be switched and controlled, allowing for the functionalisation of less-reactive positions in the presence of a priori more reactive ones. Furthermore, we show that raw materials obtained in bulk from petroleum processing, such as alkanes and unrefined mixtures of olefins, can be used as substrates. This constitutes a unique opportunity to integrate a catalytic platform en route to valuable fatty acids by direct transformation of petroleum-derived feedstocks. We anticipate that our methodology will have a broad impact in the preparation of carboxylic acids from simple chemical feedstocks, and will lead to new knowledge in synthetic design when targeting the controlled functionalisation of saturated hydrocarbon chains.
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    Walking metals for remote functionalization
    (American Chemical Society, 2018-02-08) Sommer, Heiko; Juliá Hernández, Francisco; Martin, Ruben; Marek, Ilan; Química Inorgánica
    The distant and selective activation of unreactive C−H and C−C bonds remains one of the biggest challenges in organic chemistry. In recent years, the development of remote functionalization has received growing interest as it allows for the activation of rather challenging C−H and C−C bonds distant from the initiation point by means of a “metal-walk”. A “metal-walk” or “chain-walk” is defined by an iterative series of consecutive 1,2- or 1,3-hydride shifts of a metal complex along a single hydrocarbon chain. With this approach, simple building blocks or mixtures thereof can be transformed into complex scaffolds in a convergent and unified strategy. A variety of catalytic systems have been developed and refined over the past decade ranging from late-transition-metal complexes to more sustainable iron- and cobalt-based systems. As the possibilities of this field are slowly unfolding, this area of research will contribute considerably to provide solutions to yet unmet synthetic challenges.