New Pd(0) olefin complexes, 2-5, of a binaphthalene-based chiral P,N(oxazoline) auxiliary, (S,R)-2-[4-(isopropyl)oxazol-2-yl]-2'-diphenylphosphino-1,1'-binaphthyl 1, have been prepared (olefin = fumaronitrile, maleic anhydride, 4-cyclopentene-1,3-dione, and. dibenzylideneacetone). These compounds reveal different dynamic behavior in solution as shown by 2-D exchange spectroscopy. Ligand 1 affords excellent enantioselectivity (up to 99% ee) in the allylic amination of a 1,3-diphenyl allyl precursor. The solid-state structure of [Pd(eta(3)-PhCHCHCHMe)(1)]OTf, 15, has been determined and shows two different diastereomeric cations within one unit cell; that is both the si and re faces of the allyl crystallize together, the first example of this for a moderately large allyl ligand. The structure of PdCl(2)(1) is also reported and reveals las does that for 15) that the oxazoline ring of 1 is twisted relative to the P-Pd-N coordination plane, thus placing this ring substituent above and not below the coordination plane. A more exact solid-state structure for Pd(2)(dba)(3) has been determined.
|Titolo:||Palladium(0) olefin complexes and enantioselective allylic amination/alkylation with a P,N-auxiliary|
ALBINATI, ALBERTO (Ultimo)
|Parole Chiave:||asymmetric catalysis; ligands; alkylation; amination; substitutions; isomerization; resolution; chemistry|
|Settore Scientifico Disciplinare:||Settore CHIM/03 - Chimica Generale e Inorganica|
|Data di pubblicazione:||29-mar-1999|
|Digital Object Identifier (DOI):||10.1021/om980920e|
|Appare nelle tipologie:||01 - Articolo su periodico|