31582-91-9Relevant academic research and scientific papers
Decarboxylative C(sp3)?O Cross-Coupling
Mao, Runze,Balon, Jonathan,Hu, Xile
, p. 13624 - 13628 (2018/09/25)
Alkyl aryl ethers are an important class of compounds in medicinal and agricultural chemistry. Catalytic C(sp3)?O cross-coupling of alkyl electrophiles with phenols is an unexplored disconnection strategy to the synthesis of alkyl aryl ethers, with the potential to overcome some of the major limitations of existing methods such as C(sp2)?O cross-coupling and SN2 reactions. Reported here is a tandem photoredox and copper catalysis to achieve decarboxylative C(sp3)?O coupling of alkyl N-hydroxyphthalimide (NHPI) esters with phenols under mild reaction conditions. This method was used to synthesize a diverse set of alkyl aryl ethers using readily available alkyl carboxylic acids, including many natural products and drug molecules. Complementarity in scope and functional-group tolerance to existing methods was demonstrated.
Copper Catalyzed sp3 C-H Etherification with Acyl Protected Phenols
Salvador, Tolani K.,Arnett, Charles H.,Kundu, Subrata,Sapiezynski, Nicholas G.,Bertke, Jeffery A.,Raghibi Boroujeni, Mahdi,Warren, Timothy H.
supporting information, p. 16580 - 16583 (2017/01/10)
A variety of acyl protected phenols AcOAr participate in sp3 C-H etherification of substrates R-H to give alkyl aryl ethers R-OAr employing tBuOOtBu as oxidant with copper(I) β-diketiminato catalysts [CuI]. Although 1°, 2°, and 3° C-H bonds may be functionalized, selectivity studies reveal a preference for the construction of hindered, 3° C-OAr bonds. Mechanistic studies indicate that β-diketiminato copper(II) phenolates [CuII]-OAr play a key role in this C-O bond forming reaction, formed via transesterification of AcOAr with [CuII]-OtBu intermediates generated upon reaction of [CuI] with tBuOOtBu.
Heterogeneous palladium-catalyzed synthesis of aromatic ethers by solvent-free dehydrogenative aromatization: Mechanism, scope, and limitations under aerobic and non-aerobic conditions
Sutter, Marc,Lafon, Romain,Raoul, Yann,Metay, Estelle,Lemaire, Marc
supporting information, p. 5902 - 5916 (2013/09/23)
Starting from cyclohexanone derivatives and alcohols, both non-aromatic precursors, aryl ethers could be synthesized in good yields and with good selectivities in the presence of a catalytic amount of Pd/C, in one step, without added solvent, in a reaction vessel open to air. For less reactive substrates, the addition of 1-octene in a closed system under non-aerobic conditions improved the conversion. In addition, the catalyst could be recycled several times with no decrease in the yield of the aryl ether. The process was also used with tetralone derivatives and polyols. Several reactions were performed to propose a mechanism for this transformation. The formation of an enol ether followed by a dehydrogenation reaction seem to be the key steps of this reaction. Aryl ethers were prepared in good yields and with good selectivities in a solvent-free and heterogeneous catalytic dehydrogenative alkylation of cyclohexanones with various alcohols. Three different complementary routes were used, and for the first time, non-aerobic, safe conditions could be used. Moreover, the catalyst could be recycled several times with no decrease in the yield of the aryl ether. Copyright
