Journal of the American Chemical Society · 2018 · 140 citations · 45 references
Natural SciencesChemistryCatalysisGreen ChemistryOrganic ChemistryCarboxylic AcidsCarboxylic DerivativesActivation Of Carboxylic AcidsAliphatic Carboxylic AcidsC-h ActivationCarboxylic Acid Derivative SynthesisCarboxylic Acid SynthesisCouplingsHeck ReactionPalladium Catalysts
An acetyl-protected aminoethyl phenyl thioether has been developed to promote C(sp3)–H activation. Significant ligand enhancement is demonstrated by the realization of the first Pd(II)-catalyzed olefination of C(sp3)–H bonds of free carboxylic acids without using an auxiliary. Subsequent lactonization of the olefinated product via 1,4 addition provided exclusively monoselectivity in the presence of multiple β-C–H bonds. The product γ-lactone can be readily opened to give either the highly valuable β-olefinated or γ-hydroxylated aliphatic acids. Considering the challenges in developing Heck couplings using alkyl halides, this reaction offers a useful alternative.
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A general alkyl-alkyl cross-coupling enabled by redox-active esters and alkylzinc reagents
Tian Qin, Josep Cornellà, Chao Li et al. · Science · 2016 · 744 citations
Ligand-Enabled Reactivity and Selectivity in a Synthetically Versatile Aryl C–H Olefination
Dong‐Hui Wang, Keary M. Engle, Bing‐Feng Shi et al. · Science · 2009 · 738 citations