To form an electrophile for this reaction to occur, the acyl halide interacts with the catalyst. However, on reviewing the conditions for the reaction, I have encountered that the 2 equivalence of the acyl halide is required.
In the case of the acyl chloride, there are 2 ways the acyl chloride can react with the catalyst.
(Sorry for the sloppy diagram)
In the case of the first reaction, Cl is good leaving group, but what is the reasoning of the second reaction to occur?