Copolymerization of ethylene and carbon monoxide by phosphinite-modified palladium catalysts

Synthesis and characterization of new (N‐diphenylphosphino)‐isopropylanilines and their complexes: crystal structure of (Ph2P S)NHC6H44CH(CH3)2 and catalytic activity of palladium(II) complexes in the Heck and Suzuki cross‐coupling reactions

“…It is known that in platinum(II) complexes PtCl 2 (PR 3 ) 2 , the 1 J(Pt-P) coupling constant in the cis-isomer is larger than that in the trans-isomer. [31,32] Therefore, the signal with the large 1 J( 135 Pt-31 P) coupling constant of 3926.0 Hz for 2e is assigned to the cis arrangement of phosphines around the platinum(II) center while the signal with the small 1 J ( 135 Pt-31 P) coupling constant of 3336.0 Hz is assigned to the trans arrangement. The chemical shifts for 2d can help us in assigning the signals to the respective isomer.…”

“…The 31 P-{ 1 H} NMR showed single resonances at δ(P) 52.8 ppm, δ(P) 56.1 ppm and δ(P) 60.8 ppm for 1b-3b, respectively. Compounds 1c-3c were analyzed by 31 , M = Pd 3d, M = Pt 3e, respectively, as the main products in high yields (80-90%; Scheme 2). In the complexes 1d-3d and 1e-3e, the nitrogen atom of the amine group was not involved in coordination to the metal centers because the phosphorus atoms are much stronger donors and thus coordination to the metal center takes place preferentially at the phosphorus atoms.…”

“…The decomposition of the complexes was followed in situ by 31 P NMR spectroscopy. The resonances corresponding to complexes 1d-3d gradually disappeared with concomitant formation of Ph 2 P(O)H and Ph 2 P(O)OH as indentified by signals at δ = 21 and 35 ppm, respectively.…”

“…After addition of THF, the white precipitate (triethylammonium chloride) was filtered off under argon and the solvent removed in vacuo, which was washed with cold diethyl ether (2 × 15 ml) and dried in vacuo to produce dark yellow viscous oil compound 1; yield 0.43 g (92%). 31 …”

“…The product was collected by filtration and dried in vacuo; yield 0.31 g (95%); m.p. [190][191][192] • C. 31 …”