790225-26-2Relevant academic research and scientific papers
Reactions of [(PPh3)2Pt(η3-CH 2CCPh)]+ with oxygen nucleophiles and chemistry of resultant [(PPH3)2Pt (η3-CH2C(OR)CHPh)]+ complexes
Daniel, Kirsten L,Furilla, Joan L,Wojcicki, Andrew
, p. 192 - 203 (2002)
The η3-allenyl/propargyl complex [(PPh3) 2Pt (η3-CH2CCPh)]OTf (1OTf) undergoes addition reactions with a number of oxygen nucleophiles in CH2Cl2 solution at ambient temperature. With H2O, it yields the binuclear oxygen-bridged η 3-allyl [{(PPh3)2Pt (η3- CH2CCHPh)}2O](OTf)2 (2(OTf) 2). With primary and secondary alcohols, it rapidly affords the η3-(2-alkoxyallyl) complexes [(PPh3) 2Pt(η3-CH2C(OR) CHPh)]OTf (R = Et (3OTf), i-Pr (4OTf), CH2CMe3 (5OTf), CH2CH=CH2 (7OTf)), whereas with tertiary alcohols, in slower reactions, it gives both 2(OTf)2 and [(PPh3)2Pt(η3-CH2C (OR)CHPh)]OTf (R = CMe3, C(Me)2Et (6OTf)). There is no reaction at ambient temperature between 1OTf and phenols; however, 1OTf and PhOH afford [(PPh3)2Pt(η3- CH2C(OPh)CHPh)]OTf (8OTf) in the presence of NEt3. Competition studies reveal the following reactivity order, attributed to steric effects: Me3CCH2OH(1.0) 3-(2-alkoxyallyl) complexes react with NaOMe to yield the η3- oxatrimethylemethane product (PPh3)2Pt(η 3-CH2C(O)CHPh)(10), which was also obtained by reaction of 2(OTf)2 with two equivalents of NaOMe and of 1OTf with NaOH. Complex 10 undergoes conversion to the appropriate [(PPh3)2Pt(η3-CH2C (OR)CHPh)]+ with [Et3O]PF6, (MeO)2SO2 and MeI. The η3- (2-allyloxyallyl) 7OTf reacts with (PPh3)2Pt (C2H4) to give 10 and [(PPh3) 2Pt (η3-CH2CHCH2)]OTf; thermolysis of 7OTf in toluene at reflux furnishes [(PPh3) 2Pt(η3-CH2CHCH2)] OTf, whereas heating in benzene-chloroform affords [(PPh3) 2Pt(η3-CH2C(OCH=CHMe)CHPh)]OTf (11OTf), which results from isomerization of OCH2CH=CH 2 to OCH=CHMe. Reaction pathways have been suggested for a number of the aforementioned transformations. All new complexes were characterized by a combination of elemental analysis, FAB mass spectrometry and 1H-, 13C{1H}- and 31P{1H}-NMR spectroscopy. They were assigned structures in which the η3-allyl oxygen and Ph groups are syn from the 1H-NMR spectra.
