The N-ferrocenyl-linked N-heterocyclic carbenes 1a and 1b were obtained by treatment of their imidazolium salts 12a and 12b with potassium tert-butoxide. The latter were shown to be accessible from (R)-1-amino-2-methylferrocene (9) and aminoferrocene, respectively, which were converted into the corresponding formamidines and then subjected to a novel cyclization procedure. Treating the ligand precursors 12a and 12b with [Pd(OAc) 2 ] 3 under different reaction conditions afforded the trans-pyridine-substituted Pd II complexes 14a and 14b as well as their trans-triphenylphosphane-substituted

A study of the secondary interactions involving a pendant phenethyl group (NCH(CH 3 )Ph) of (S a ,R C ,R C )-O,O′-[1,1′-binaphthyl-2,2′-diyl]-N,N′-bis[1-phenylethyl]phosphoramidite (1) in d 8 and d 6 metal complexes is reported. A 1,2-η-phenyl interaction is found in [Pd(η 3 -allyl)(1,2-η-Ph-1-κP)] + (3), as indicated by NMR spectroscopy and by an X-ray study. The Rh(I) complexes [RhCl(NBD)(1-κP)] (4a) and [RhCl(COD)(1-κP)] (4b) were prepared, and their X-ray structures were determined. Chloride abstraction from 4a and 4b gave the corresponding cations [Rh(NBD)(1,2-η-Ph-1-κP)] + (5a) and [Rh(COD)(1,2η-Ph-1-κP)] + (5b), which were fully characterized. Besides NMR spectroscopic data, the 1,2-η-phenyl interaction is supported by an X-ray study of 5a. Upon standing in MeOH solution, 5b undergoes loss of the COD and forms [Rh(1-κP)(η 6 -Ph-1-κP)] + (6), whose η 6 -arene coordination was studied by NMR spectroscopy and by X-ray diffraction. For the sake of comparison with the d 8 complex 6, the crystal structure of the previously reported d 6 analogue [RuCl 2 (η 6 -Ph-1-κP)] + (7) was determined. This study shows that secondary π-arene-metal interactions turn phosphoramidite 1 to a four-, six-, or eight-electron donor, with increasing bond strength in this order.

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A practical aminocyclization of 1,6-enynes with a wide variety of substituted anilines, including N-alkyl anilines, has been achived by using cationic [JohnPhosAu(MeCN)]SbF6 as a general purpose catalyst. The resulting adducts can be easily converted into polycyclic compounds by palladium- and gold-catalyzed reactions.

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