- Structure determination and DFT studies of some new phosphite-based cycloplatinated(II) complexes containing biphosphine ligands
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The starting complex [PtCl{(κ2-P,C)P(OC6H4) (OPh)2}SMe2], 3, was prepared by a new method using the reaction of [PtCl2(P(OPh)3)2] with 1 equiv of PtCl2 in x
- Paziresh, Sareh,Aghakhanpour, Reza Babadi,Esmaeilbeig, Ahmad R.
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- Characterization and phenylacetylene-assisted cyclometalation of an isolable hydrido-selenolato PtII complex having phosphite ligands, cis-[PtH(SeTrip){P(OPh)3}2]#
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A hydridoselenolato PtII complex having P(OPh)3 ligands, cis-[PtH(SeTrip){P(OPh)3}2] (Trip: 9-triptycyl), was synthesized by the reaction of TripSeH with [Pt{P(OPh)3} 2]. The structure was characterized by NMR spectroscopy and X-ray crystallography in comparison with the corresponding PPh3 complex, cis-[PtH(SeTrip)(PPh3)2], indicating the stronger coordination of P(OPh)3 to the Pt center than that of PPh 3. On heating at 130 °C in xylene for 17 h, cis-[PtH(SeTrip)- {P(OPh)3}2] was converted to the corresponding 1,2-selenaplatinacycle (SP-42)-[Pt(kC1,kSe9-TripSe(2-)) {P(OPh)3}2] through an intramolecular cyclization (cyclometalation). The reaction with dimethyl acetylenedicarboxylate (DMAD) gave a mixture of hydroselenation products (E)- and (Z)-(MeO2C)CH= C(SeTrip)CO2Me non-stereoselectively together with 1H-2-benzoselenin, dimethyl 7H-7,11b[1',2']-benzenoanthra[9,1-bc]selenin-2,3-dicarboxylate. In the reaction with phenylacetylene in toluene at 110 °C, phenylacetylene served as a hydrogen acceptor to form the 1,2-selenaplatinacycle and styrene. Based on the results of controlled experiments using cis-[PtD(SeTrip){P(OPh) 3}2] and phenylacetylene-d, the mechanism of the cyclometalation was proposed as the 1,2- (major) and 2,1- (minor) insertions of phenylacetylene into the Pt-H bond followed by cyclometalation between the Pt center and the triptycyl group. The reaction with phenylacetylene in the presence of excess P(OPh)3 furnished a 1,2,3-oxaphosphaplatinacycle, (SP-4-2)-[Pt{kC,kP-(Z)-CH=C(Ph)-OP(OPh)2}(SeTrip){P(OPh) 3}], as a minor product, together with the 1,2-selenaplatinacycle in a decreased yield.
- Kamon, Hitomi,Aoki, Yutaro,Nakata, Norio,Ishii, Akihiko
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p. 274 - 282
(2014/03/21)
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- Platinum complexes of aromatic selenolates
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Several synthetic methods are used to prepare naphthalene based aromatic 1,2-diselenoles. A new one-pot synthesis starting from naphthalene is used to produce the known compound naphtho[1,8-c,d][1,2]diselenole (Se2naph). Friedel-Crafts alkylation is used on Se2naph to substitute either one tert-butyl group to form 2-tert-butylnaphtho[1,8-c,d][1,2]diselenole (mt-Se2naph) or two tert-butyl groups to form 2,7-di-tert- butylnaphtho[1,8-c,d][1,2]diselenole (dt-Se2naph). Bromination of mt-Se2naph results in dibromination of the naphthalene ring, rather than reaction at selenium, to give 4,7-dibromo-2-tert-butylnaphtho[1,8-c,d][1,2] -diselenole (mt-Se2naphBr2). Reduction of the Se-Se bond in Se2naph, mt-Se2naph, dibenzo[c,e][1,2]diselenine (dibenzSe2), or diphenyl diselenide (Se2Ph2) with LiBEt3 H, followed by in-situ addition of [PtCl 2{P(OPh)3}2] yields the fourcoordinate mono-and dinuclear platinum(II) bis(phosphite) complexes [Pt(Se2naph){P(OPh) 3}2] (1), [Pt(mt-Se2naph)-{P(OPh) 3}2] (2), [Pt2(dibenzSe2) 2{P(OPh)3}2] (3), cis-[Pt(SePh) 2-{P(OPh)3}2] (4), and trans-[Pt 2(SePh)4{P(OPh)3}2] (5).
- Fuller, Amy L.,Knight, Fergus R.,Slawin, Alexandra M. Z.,Woollins, J. Derek
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p. 4034 - 4043
(2011/01/07)
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- Syntheses and characterization of novel bis(phosphoranido)platinum(II) complexes: Reactions of lithium bis(naphth-l,8-diyl-8-oxy)phosphoranide with cis-PtCl2(PRs)2 (R = OPh, OMe, Me)
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The reactions of cis-PtCl2(PR3J2 (R = OPh, OMe) with 1 equiv. of lithium, phosphoranide generated from, a bis(naphth-1,8diyl-8-oxy)phosphorane lead to the formation of cis-monophosphoranido complexes with high stereospecificity. The reaction of cis-PtCl2(PMe3)2 with 1 equiv. of the lithium, phosphoranide afforded a trans-monophosphoranido complex, exclusively. Hitherto unknown trans-bis(phosphoranido)platinum.(II) complexes were obtained as major products in the reactions of cis-PtCl2(PR3)2 (R = OPh, OMe, Me) with an excess of the lithium phosphoranide. The stereochemistry was confirmed by X-ray structural analysis of the bis(phosphoranido) complex bearing triphenyl phosphites.
- Kajiyama, Kazumasa,Sato, Issei,Yamashita, Satoru,Miyamoto, Takeshi K.
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p. 5516 - 5521
(2010/06/15)
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- Synthesis and NMR spectroscopy of cyclopalladated tertiary phosphite complexes. X-ray crystal structure of Pd(η5-C5H5)(P(OPh)2(OC6H4))
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The paper reports the authors' initial studies on the cyclometalation and characterization of complexes derived from P(OPh)3 and P(OEt)2(OPh), with the latter ligand selected so that after cyclometalation and subsequent transformation (e.g., carbonylation), hydrolysis would readily yield the ortho-substituted phenol. For comparison purposes the authors have also prepared and cyclopalladated P(OEt)2(NMePh), an N-methylaniline analog. In the course of this work, the crystal structure of Pd(η5-C5H5)(P(OPh)2(OC6H4)) was determined and found to contain some interesting features, which are discussed as well.
- Albinati,Affolter,Pregosin
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p. 379 - 387
(2008/10/08)
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