Two classes of cationic palladium(II) phosphine carboxylate complexes were isolated and characterized. Reactions of trans-[(R3P)(2)Pd(O2CR')(2)] (1) with [Li(OEt2)(2.5)][B(C6F5)(4)] in MeCN led to carboxylate abstraction and formation of trans-[(R3P)(2)Pd(O2CR')(MeCN)][B(C6F5)(4)] (2) in good to excellent yields. On the other hand, carboxylate abstraction reactions of 1 with [Me-2(H)NPh][B(C6F5)(4)] or p-toluenesulfonic acid (HOTs center dot H2O) in CH2Cl2 furnished the palladium cations [(R3P)(2)Pd(kappa(2)-O,O-O2CR')](+) (3). The reactions of 2 and 3 with Lewis bases were found to be different in some cases. For example, reactions of 2 with pyridine furnished the simple products of acetonitrile substitution, trans-[(R3P)(2)Pd(O2CR')(py)][B(C6F5)(4)]. In contrast, the reaction of 3e (R = Pr-i, R' = CH3) with CD3CN in the presence of excess sodium carbonate yielded a material derived from cyclometalation of one of the Pr-i arms of a (Pr3P)-Pr-i ligand. New complexes were characterized by elemental analyses and NMR (H-1, C-13, and P-31) spectroscopic methods and in two cases by single-crystal X-ray structural methods.
Two classes of cationic palladium(II) phosphine carboxylate complexes were isolated and characterized. Reactions of trans-[(R3P)(2)Pd(O2CR')(2)] (1) with [Li(OEt2)(2.5)][B(C6F5)(4)] in MeCN led to carboxylate abstraction and formation of trans-[(R3P)(2)Pd(O2CR')(MeCN)][B(C6F5)(4)] (2) in good to excellent yields. On the other hand, carboxylate abstraction reactions of 1 with [Me-2(H)NPh][B(C6F5)(4)] or p-toluenesulfonic acid (HOTs center dot H2O) in CH2Cl2 furnished the palladium cations [(R3P)(2)Pd(kappa(2)-O,O-O2CR')](+) (3). The reactions of 2 and 3 with Lewis bases were found to be different in some cases. For example, reactions of 2 with pyridine furnished the simple products of acetonitrile substitution, trans-[(R3P)(2)Pd(O2CR')(py)][B(C6F5)(4)]. In contrast, the reaction of 3e (R = Pr-i, R' = CH3) with CD3CN in the presence of excess sodium carbonate yielded a material derived from cyclometalation of one of the Pr-i arms of a (Pr3P)-Pr-i ligand. New complexes were characterized by elemental analyses and NMR (H-1, C-13, and P-31) spectroscopic methods and in two cases by single-crystal X-ray structural methods.