کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1322061 1499917 2012 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Versatile nuclephilic Michael addition to chelated (Ph2P)2CCH2 (vdpp) in Schiff base cyclometallated palladium(II) compounds: C–C, C–O and C–N bond formation, dinuclear palladacycles and geometrical isomerism
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Versatile nuclephilic Michael addition to chelated (Ph2P)2CCH2 (vdpp) in Schiff base cyclometallated palladium(II) compounds: C–C, C–O and C–N bond formation, dinuclear palladacycles and geometrical isomerism
چکیده انگلیسی

Treatment of the mononuclear complex [Pd{2,4-(MeO2)C6H2C(H)N(Cy)-C6,N}{(Ph2P)2CCH2-P,P′}][PF6] (1) with methyl 2-oxocyclopentanecarboxilate, α-acetylbutyrolactone or methyl phenylsulfonylacetate in the presence of anhydrous sodium carbonate yielded the addition products [Pd{2,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{(Ph2P)2CHCH2C(R1)(R2)-P,P′}][PF6] (R1 = COOCH3, R2 = COCH2CH2CH2, 2; R1 = COCH3, R2 = COOCH2CH2, 3; R1 = COOCH3, R2 = SO2Ph, 4) in high yield. The existence of two chiral carbon atoms in the diphosphine moiety produces the existence of optical isomers. Reaction of 1 with acetone and potassium tert-butoxide afforded complex [Pd{2,4-(Me)2C6H2C(H)N(Cy)-C6,N}{(Ph2P)2CHCH2CH2COCH3-P,P′}][PF6] (5), via C–C bond formation. Complex 1 reacts in methanol and in ethanol to give the corresponding addition products [Pd{2,4-(MeO)2C6H2C(H)NCy-C6,N}{(Ph2P)2CHCH2OR-P,P′}][PF6] (R = CH3, 6; R = CH2CH3, 7), via C–O bond formation. Treatment of complex 1 with cyclohexylamine or dimethylhidrazine gives place to [Pd{2,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{(Ph2P)2CHCH2N(H)R–P,P′}][PF6] (R = C6H11, 8; R = N(CH3)2, 9), via C–N formation. The crystal structure of 7 has been determined by X-ray crystallography and comprises equimolar amounts of the (C16R) and (C16S) enantiomers. Reaction of compound 1 with dl-alanine or dl-metionine and anhydrous sodium carbonate yields [Pd{2,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{(Ph2P)2CHCH2NHCH(R1)(R2)-P,P′}][PF6] (R1 = CH3, R2 = COOH, 10; R1 = CH2CH2SCH3, R2 = COOH, 11). Treatment of complex 1 with piperazine give rise to the dinuclear compound [{Pd[2,4-(MeO)2C6H2C(H)N(Cy)-C6,N]}2{(Ph2P)2CHCH2N(CH2CH2)2NCH2CH(PPh2)2-P,P,P′,P′}][PF6]212, in which each N–H bond of the piperazine has been added to the vinylidene bond of one vdpp ligand.

Chelated (Ph2P)2CCH2 (vdpp) in Schiff base palladacycles is activated towards Michael addition to give compounds with new C–C, C–O and C–N bonds.Figure optionsDownload as PowerPoint slideHighlights
► Activation of (Ph2P)2CCH2 (vdpp) towards Michael addition reactions.
► Geometrical isomerism in the addition products of (Ph2P)2CCH2 (vdpp).
► Double addition of a cyclic diamine.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Organometallic Chemistry - Volume 720, 1 December 2012, Pages 30–37
نویسندگان
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