Catalytic C–H Borylation: From Madness to Method

Seminar series
Inorganic Chemistry
Wed, Apr 17 4:30pm
Cram Conference Room, 3440 Mol Sci
Speaker Professor Milton R. Smith, III
Michigan State University
Department of Chemistry

Chemists have sought methods for functionalizing sp2-C–H bonds that complement Electrophilic Aromatic Substitutions. Building from the first thermal, catalytic coupling of a borane and a hydrocarbon,1 our research group,2 and others, have developed highly active iridium catalysts that exhibit unique regioselectivities for arene substitution and remarkable chemoselectivity for C–H functionalization. For example, sp2-C–X bonds (X = Cl, Br, and I) that are commonly cleaved in reactions with late transition metal complexes are typically inert to the Ir catalysts. Consequently, these substrates generally give C–H borylated products. Extensions to heterocyclic substrates and development of one-pot, catalytic reactions where the boronate esters are further transformed make C—H borylation particularly attractive to synthetic chemists.

(1) Iverson, C. N.; Smith, M. R. III J. Am. Chem. Soc. 1999, 121, 7696-7697.
(2) Cho, J.-Y; Tse, M. K.; Holmes, D; Maleczka, R. E. Jr.; Smith, M. R. III Science 2002, 295, 305-308.
(3) Vanchura, B. A.; Preshlock, S. M.; Roosen, P. C.; Kallepalli, V. A.; Staples, R. J.; Maleczka, R. E. Jr.; Singleton, D. A.; Smith, M. R. III Chem. Commun. 2010, 46, 7724.