Electroorganic synthesis is a highly attractive technique to synthesize non-symmetric biphenols. These substances offer a unique structural motif in natural products and are important ligands for catalysts.[1] Typically, cross-coupling reactions need expensive transition-metal catalysts for the construction of biphenols.[2] Furthermore, commonly used methods require leaving groups or oxidizers. This leads to significant amounts of reagent waste during these cross-coupling reactions.

We established efficient pathways for the C,H activation cross-coupling to non-symmetric biphenols with tolerance of broad substitution pattern and a broad range of current density[3]. In this method, reagent waste is significally avoided due to electrons being the only reagent. Efficient and straightforward electro-organic reactions are highly attractive and sustainable.[4] Therefore, our developed method is ecological as well as economic and represents an inherently safe, and easily scalable alternative synthetic approach, which is superior to other oxidizers.[5]

References:

[1] (a) G. Bringmann, T. Gulder, T. A. M. Gulder, M. Breuning, Rev. 2011, 111, 563–639; (b) J. M. Brunel, Chem. Rev. 2005, 105, 857–898.

[2] (a) L. Ackermann, Modern Arylation Methods, Wiley-VCH, Weinheim, 2009; b) G. Dyker, Handbook of C-H Transformations, Wiley-VCH, Weinheim, 2005.

[3] Wiebe, B. Riehl, S. Lips, R. Franke, S. R. Waldvogel, Sci. Adv. 2017, 3:eaao3920.

[4] Elsler, D. Schollmeyer, K. M. Dyballa, R. Franke, S. R. Waldvogel, Angew. Chem. 2014, 126, 5311–5314; Angew. Chem. Int. Ed. 2014, 53, 5210–5213.

[5] Riehl, K. M. Dyballa, R. Franke, S. R. Waldvogel, Synthesis 2017, 49, 252–259.