화학공학소재연구정보센터
Inorganic Chemistry, Vol.51, No.10, 5950-5964, 2012
Amidoximes Provide Facile Platinum(II)-Mediated Oxime-Nitrile Coupling
The nucleophilic addition of amidoximes R'C(NH2)=NOH [R' = Me (2.Me), Ph (2.Ph)] to coordinated nitriles in the platinum(II) complexes trans-[PtCl2(RCN)(2)] [R = Et (1t.Et), Ph (1t.Ph), NMe2 (1t.NMe2)] and cis-[PtCl2(RCN)(2)] [R = Et (1c.Et), Ph (1c.Ph), NMe2 (1c.NMe2)] proceeds in a 1:1 molar ratio and leads to the monoaddition products trans-[PtCl(RCN){H (N) under bar =C(R)O (N) under barC(R')NH2}]Cl [R = NMe2; R' = Me ([3a]Cl), Ph ([3b]Cl)], cis-[PtCl2{H (N) under bar =C(R)O (N) under barC(R')NH2}] [R = NMe2; R' = Me (4a), Ph (4b)], and trans/cis-[PtCl2(RCN){H (N) under bar =C(R)ONC(R')NH2}] [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{H (N) under bar =C(R)O (N) under barC(R')NH2}(2)]Cl-2 [R = NMe2; R' = Me ([7a]Cl-2, [8a]Cl-2), Ph ([7b]Cl-2, [8b]Cl-2)] and trans/cis-[PtCl2{H (N) under bar =C(R)ONC(R')NH2}(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 AgNO3. 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 H-1 NMR techniques, while 4a, 4b, 5b, 6d, [7b](Cl)(2), [7d](SO3CF3)(2), [8b](Cl)(2), [8f](NO3)(2), 9b, and 10b were also characterized by single-crystal X-ray diffraction.