A meta‐Selective C−H Alumination of Mono‐Substituted Benzene by Using An Alkyl‐Substituted Al Anion through Hydride‐Eliminating S_NAr Reaction

Abstract

Reaction of an Al-centered anion with toluene proceeded to form CÀH cleaved product with a perfect metaselectivity and a relatively small kinetic isotope effect (KIE, k H / k D = 1.51). DFT calculations suggested a two-step reaction mechanism and electronically controlled meta-selectivity arising from the electron-donating methyl group. The reaction with other mono-substituted arenes was also investigated.

Hydroarylation of olefins catalysed by a dimeric ytterbium(II) alkyl

“…In contrast, hydroarylation, the addition of an arene C-H bond across olefins, offers significant advantages over classical Friedel-Crafts alkylation as the reaction is by-product free and the olefin starting materials are generally cheaper and more readily available compared to the corresponding alkyl halide. While a number of potent nucleophilic main group species have very recently been shown to activate and functionalise aryl C-H bonds [3][4][5][6][7][8][9] , only transition metal complexes have, thus far, provided an alternative catalytic pathway to new alkylated arene products (Fig. 1b) [10][11][12][13][14] .…”

Hydroarylation of olefins catalysed by a dimeric ytterbium(II) alkyl

“…In contrast, hydroarylation, the addition of an arene C-H bond across olefins, offers significant advantages over classical Friedel-Crafts alkylation as the reaction is by-product free and the olefin starting materials are generally cheaper and more readily available compared to the corresponding alkyl halide. While a number of potent nucleophilic main group species have very recently been shown to activate and functionalise aryl C-H bonds [3][4][5][6][7][8][9] , only transition metal complexes have, thus far, provided an alternative catalytic pathway to new alkylated arene products (Fig. 1b) [10][11][12][13][14] .…”