摘要:
Compounds of the formula (I) 1 in which Q1 and Q2 are each OH or form a trimeric boric anhydride, Z is CHO, CH2Y, X or a protected aldehyde group, and X is CN, COOH, COCl, CONH2 or C(OR)3, and Y is OH or NH2, and Z is in the o-, m- or p-position to the boronic acid radical, are prepared by a) reacting a compound of the formula (II) 2 nullwith Mg in the presence of an anthracene compound and, if desired, a transition-metal halide and, if desired, an Mg halide or in the presence of a transition-metal halide and, if desired, an Mg halide, to give the corresponding arylmagnesium chloride, b) reacting the latter with a borate of the formula B(ORnull)3 and hydrolyzing the product, with removal of the aldehyde protecting group, c) and, if desired, oxidizing or reducing the free aldehyde group.
摘要:
The novel two-stage process described here makes it possible to obtain substituted benzyl compounds and toluene derivatives in a simple manner and in high yields by means of Suzuki-type coupling reactions of an aromatic with an organoboron compound, followed by a reduction. The process is particularly useful for preparing ortho-substituted benzyl compounds and toluene derivatives. The process can be applied to both intermolecular and intramolecular coupling reactions. Catalysts used for the coupling reaction are palladium compounds and/or nickel compounds. An advantageous aspect is that only very small amounts of catalyst are required.