Palladium complexes reaction with mineral acids

Reaction of the bis(salicylidenimine)palladium(II) complexes with mineral acids yields N-bonded complexes tranr-[PdX2(LH)2] (X = Cl, Br, I, SCN LH = HOC6H4CHNPh).243... 

The acid-catalyzed hydrocarboxylation of alkenes (the Koch reaction) can be performed in a number of ways. In one method, the alkene is treated with carbon monoxide and water at 100-350°C and 500-1000-atm pressure with a mineral acid catalyst. However, the reaction can also be performed under milder conditions. If the alkene is first treated with CO and catalyst and then water added, the reaction can be accomplished at 0-50°C and 1-100 atm. If formic acid is used as the source of both the CO and the water, the reaction can be carried out at room temperature and atmospheric pressure.The formic acid procedure is called the Koch-Haaf reaction (the Koch-Haaf reaction can also be applied to alcohols, see 10-77). Nearly all alkenes can be hydrocarboxylated by one or more of these procedures. However, conjugated dienes are polymerized instead. Hydrocarboxylation can also be accomplished under mild conditions (160°C and 50 atm) by the use of nickel carbonyl as catalyst. Acid catalysts are used along with the nickel carbonyl, but basic catalysts can also be employed. Other metallic salts and complexes can be used, sometimes with variations in the reaction procedure, including palladium, platinum, and rhodium catalysts. The Ni(CO)4-catalyzed oxidative carbonylation with CO and water as a nucleophile is often called Reppe carbonylationP The toxic nature of nickel... 

Electrophilic reagents, including Br2, CI2, NCS-SCN, and I2, will react rapidly and in high yield to add across the Pd-C bond. Mineral acids will cleave the bond in cyclometalated complexes as well. Since cyclometalation with palladium halide complexes generates HCl, frequently a weak base, such as sodium acetate, is added to prevent reversal of the cyclometalation reaction. 

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