1174525-47-3Relevant academic research and scientific papers
Optically active mixed unsymmetric imine platinum(II) complexes - Utilization of the liberated imines for further syntheses of mixed imine-diazadiene complexes and of (E)-cyanoalkenes
Lasri, Jamal,Guedes Da Silva, M. Fatima C.,Charmier, M. Adilia Januario,Pombeiro, Armando J. L.
, p. 3668 - 3677 (2008)
Treatment of trans-[PtCl2(NCR)2] (1) {R = CH 2CO2Me (1a), Ph (1b)} with (R*)-camphor oxime (C9H16)C=NOH (2) gives access to the optically active mixed imine-nitrile complexes trans-(R*)-[PtCl2{NH=C(R)ON= C(C9H16)}(NCR)] (4), which, on reaction with ketoximes R1R2C=NOH (3) {R1 = R2 = Me (3a), C4H8 (3b)}, give the chiral unsymmetric bis(imine) complexes trans-(R*)-[PtCl2{NH=C(R)ON=C(C9H 16)}{NH=C(R)-ON=CR1R2}] (6) in moderate yields. An alternative route involves the reaction of the starting complexes 1 with ketoximes 3 to give the mixed imine-nitrile complexes trans-[PtCl 2{NH=C(R)ON=CR1R2}(NCR)] (5), followed by reaction of the latter with (R*)-camphor oxime (2) to afford products 6 in similar yields. Treatment of complexes 1 or 4 with two or one equivalent of 2, respectively, gives the symmetrical bis-(imine) complexes trans-[PtCl 2{NH=C(R)ON=C(C9H16)}2] (7). These reactions are accelerated by microwave irradiation to afford, in better yields (71-50%), the same products. The new optically active diimine compounds NH=C(R)ON=C-(C9H16) (8) are quantitatively liberated upon reaction of complexes 7 with a diphosphane. The chiral diimino ester 8a (R = CH2CO2Me) acts as a protic nucleophile and efficiently couples with the coordinated nitrile in 4 to give the new optically active, mixed, unsymmetric imine-1,3-diaza-1,3-diene complexes trans-(R*,R*) -[PtCl2{NH=C(R)ON=C(C9H16)}{NH= C(R)N=C(CH 2CO2Me)ON=C(C9H16)}] (9). Diimino ester 8a with an acidic α-methylene group also reacts with acyclic nitrones -O+N(Me)=C(H)R′ (10) to afford stereoselectively the (E)-cyanoalkenes (N≡C)C(CO2Me)=C(H) R′ (11) {R′ = 4-MeC6H4 (11a), 2,4,6-Me 3C6H2 (11b)}. All of these compounds were characterized by IR and NMR (1H, 13C, and 195Pt for metal complexes) spectroscopy, ESI-MS or FAB-MS, elemental analysis, and X-ray diffraction analysis (for 5c and 7b). Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
PtII-mediated imine-nitrile coupling leading to symmetrical (1,3,5,7,9-pentaazanona-1,3,6,8-tetraenato)Pt(II) complexes containing the incorporated 1,3-diiminoisoindoline moiety
Lasri, Jamal,Kuznetsov, Maxim L.,Guedes Da Silva, M. Fatima C.,Pombeiro, Armando J. L.
, p. 10774 - 10786,13 (2020/09/02)
Treatment of trans-[PtCl2(NCR)2] (1; R = Et (1a), Ph (1b)) with 1,3-diiminoisoindoline (2) gives access to the corresponding symmetrical (1,3,5,7,9-pentaazanona-1,3,6,8-tetraenato)Pt(II) complexes [PtCl{NH=C(R)N=C(C6H4)NC=NC(R)=NH}] (3). The reactions of 1 with one equivalent of 1,1,3,3-tetramethylguanidine (4), 1,3-diphenylguanidine (6), or acetone oxime (8) leads to the formation of mixed asymmetrical Pt(II) complexes trans-[PtCl2{NH=C(R)N=C(NMe2)2}(NCR)] (5), [PtCl{NH=C(R)NC(NHPh)=NPh}(NCR)] (7), or trans-[PtCl2{NH=C(Ph) ON=CMe2}(NCPh)] (9), respectively, as a result of nucleophilic addition to one of the nitrile ligands in 1. Treatment of 5, 7, and 9 with one equivalent of 2 leads to complexes 3. The complexes were characterized by IR, 1H, 13C{1H}, and 195Pt NMR (for 3) spectroscopies, ESI+-MS, elemental analyses, and X-ray diffraction (for 3). Complex 3a has an asymmetric unit with five independent Pt molecules of the same chemical composition and two molecules of water, resulting in a total of 40 molecules of the complex and sixteen guest water molecules per unit cell. Theoretical calculations revealed that the most plausible mechanism of formation of complexes 3 includes stepwise nucleophilic addition of 2 to one of the nitrile ligands in 1, a first cyclization upon formation of the Pt-N bond and elimination of HCl, and a second nucleophilic addition/cyclization.
