Amidoximes provide facile platinum(II)-mediated oxime-nitrile coupling

The nucleophilic addition of amidoximes R'C(NH(2))═NOH R' = Me (2.Me), Ph (2.Ph)] to coordinated nitriles in the platinum(II) complexes trans-PtCl(2)(RCN)(2)] R = Et (1t.Et), Ph (1t.Ph), NMe(2) (1t.NMe(2))] and cis-PtCl(2)(RCN)(2)] R = Et (1c.Et), Ph (1c.Ph), NMe(2) (1c.NMe(2))] proceeds in a 1:1 molar ratio and leads to the monoaddition products trans-PtCl(RCN){HN═C(R)ONC(R')NH(2)}]Cl R = NMe(2); R' = Me (3a]Cl), Ph (3b]Cl)], cis-PtCl(2){HN═C(R)ONC(R')NH(2)}] R = NMe(2); R' = Me (4a), Ph (4b)], and trans/cis-PtCl(2)(RCN){HN═C(R)ONC(R')NH(2)}] R = Et; R' = Me (5a, 6a), Ph (5b, 6b); R = Ph; R' = Me (5c, 6c), Ph (5d, 6d), correspondingly]. If the nucleophilic addition proceeds in a 2:1 molar ratio, the reaction gives the bisaddition species trans/cis-Pt{HN═C(R)ONC(R')NH(2)}(2)]Cl(2) R = NMe(2); R' = Me (7a]Cl(2), 8a]Cl(2)), Ph (7b]Cl(2), 8b]Cl(2))] and trans/cis-PtCl(2){HN═C(R)ONC(R')NH(2)}(2)] R = Et; R' = Me (10a), Ph (9b, 10b); R = Ph; R' = Me (9c, 10c), Ph (9d, 10d), respectively]. The reaction of 1 equiv of the corresponding amidoxime and each of 3a]Cl, 3b]Cl, 5b-5d, and 6a-6d leads to 7a]Cl(2), 7b]Cl(2), 9b-9d, and 10a-10d. Open-chain bisaddition species 9b-9d and 10a-10d were transformed to corresponding chelated bisaddition complexes 7d](2+)-7f](2+) and 8c](2+)-8f](2+) by the addition of 2 equiv AgNO(3). All of the complexes synthesized bear nitrogen-bound O-iminoacylated amidoxime groups. The obtained complexes were characterized by elemental analyses, high-resolution ESI-MS, IR, and (1)H NMR techniques, while 4a, 4b, 5b, 6d, 7b](Cl)(2), 7d](SO(3)CF(3))(2), 8b](Cl)(2), 8f](NO(3))(2), 9b, and 10b were also characterized by single-crystal X-ray diffraction.