The copper-catalyzed Chan-Evans-Lam coupling reaction is a powerful method to form carbon–nitrogen and carbon–oxygen bonds. In most cases, the reaction requires the use of boronic acids. The synthesis and isolation of boronic acids can be impractical in some cases. For this reason, recent developments in the Chan-Evans-Lam reaction have included the direct use of aryl and alkyl boronate esters. While progress has been made in this area, none of the transformations are general, only applying to arylboronate esters and alkyl amines, for example. The direct coupling of <i>ortho</i>-borylated (pinacolatoboronate) benzylic amines with anilines and phenols has been established by our group, providing facile synthesis of biaryl amines and ethers with a pendant benzylic amine. These two transformations each have unique reactivity that will be discussed including the increased selectivity in the amination reaction with no added base, and a strong dependence on base for the coupling of phenols, particularly electron-deficient phenols. Proposed mechanisms to account for the unique reactivity and observed byproducts will be included. Finally, progress on extending this direct coupling to organoboronate esters lacking the adjacent benzylic amine will be described.

Chan-Evans-Lam amination and etherification directly from organoboronate esters

254th National Meeting (2017)

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