One-pot ipso-hydroxylation and ortho-/para-halogenation of (hetero)arylboronic acids under tungsten catalysis

Abstract

The one-pot ipso-hydroxylation-(decarboxylative)-halogenation of (hetero)aryl boronic acids under mild conditions has been developed, in which the (hetero)aryl boronic acids also promoted the reaction by releasing B(OH)3 as a Lewis acid for H2O2, hypohalite and tungsten catalyst.

Directing group controlled regioselective C–H borylation of 2-arylphenolic compounds at room temperature

“…As previously reported, the para -substituted phenyl (B ring) failed to give the borylation product in the presence of BBr 3 without a catalyst ( 1n ). 25 However, in our reaction, the B-aryl motif bearing either electron-donating or neutral para -substitutes ( 1n–1p ) gave good to excellent yields of DAOBs. The para -ether cannot be tolerated either, affording the free hydroxy in the final product ( 1q ).…”

“…Therefore, the desired selective C2′- and ortho -borylation of 2-arylarenolic compounds could be achieved with LA/BBr 3 by hydroxyl- and ester/carbamate-directed respective borylation at room temperature. Herein, as part of our continuing research into arylboronic acids, 25 we present DG-controlled regioselective borylation of arenolic compounds with Fe(OTf) 3 /BBr 3 . Highly-controlled regioselectivity, a broad substrate scope, good-to-excellent yields, and gram-scale synthesis were all achieved (Scheme 1D).…”