Metal-free directed sp(2)-C-H borylation

Lv, JH; Chen, XY; Xue, XS; Zhao, BL; Liang, Y; Wang, MY; Jin, LQ; Yuan, Y; Han, Y; Zhao, Y; Lu, Y; Zhao, J; Sun, WY; Houk, KN; Shi, ZZ

Shi, ZZ (reprint author), Nanjing Univ, Sch Chem & Chem Engn, Chem & Biomed Innovat Ctr ChemBIC, State Key Lab Coordinat Chem, Nanjing, Jiangsu, Peoples R China.; Shi, ZZ (reprint author), Yangzhou Univ, Coll Chem & Chem Engn, Yangzhou, Jiangsu, Peoples R

NATURE, 2019; 575 (7782): 336

Abstract

Organoboron reagents are important synthetic intermediates that have a key role in the construction of natural products, pharmaceuticals and organic materials(1). The discovery of simpler, milder and more efficient approaches to organoborons can open additional routes to diverse substances(2-5). Here we show a general method for the directed C-H borylation of arenes and heteroarenes without the use of metal catalysts. C7- and C4-borylated indoles are produced by a mild approach that is compatible with a broad range of functional groups. The mechanism, which is established by density functional theory calculations, involves BBr3 acting as both a reagent and a catalyst. The potential utility of this strategy is highlighted by the downstream transformation of the formed boron species into natural products and drug scaffolds.

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