A method of alkylating or acylating an arene includes reacting the arene with an organic halide in the presence of an aprotic solvent and a catalyst of formula (I)

MR.sup.1.sub.mX.sub.n.Z(R.sup.2)(R.sup.3)(I)

wherein M is Al, Ga, or Fe; R.sup.1 is C.sub.1-C.sub.12 alkyl; m is 0 or 1; R.sup.2 and R.sup.3 are each independently unsubstituted or substituted C.sub.2-C.sub.12 alkyl; each occurrence of X is independently a halogen; n is 2 or 3; the sum of m and n is 3; and Z is S or O. When M is Al, then m is 1, n is 2, and R.sup.2 and R.sup.3 are each independently substituted with at least one electron-withdrawing group. When M is Ga or Fe, then m is 0 and n is 3.

The present disclosure provides a device for continuously preparing 2,6-dihydroxybenzaldehyde and use thereof. The device includes a first continuous reaction unit for hydroxy protection reaction, a second continuous reaction unit for lithiation and hydroformylation, and a third continuous reaction unit for deprotection reaction that are connected in series. The third continuous reaction unit includes: a first columnar continuous reactor, connected to the second continuous reaction unit and used for deprotection of the lithiated hydroformylated product while performing liquid separation to obtain an organic phase containing 2,6-dihydroxybenzaldehyde and an aqueous phase.

The present disclosure provides a device for continuously preparing 2,6-dihydroxybenzaldehyde and use thereof. The device includes a first continuous reaction unit for hydroxy protection reaction, a second continuous reaction unit for lithiation and hydroformylation, and a third continuous reaction unit for deprotection reaction that are connected in series. The third continuous reaction unit includes: a first columnar continuous reactor, connected to the second continuous reaction unit and used for deprotection of the lithiated hydroformylated product while performing liquid separation to obtain an organic phase containing 2,6-dihydroxybenzaldehyde and an aqueous phase.