Cyclopalladated ferrocenyl

Hollis TK, Overman LE (1997) Cyclopalladated ferrocenyl amines as enantioselective catalysts for the rearrangement of allylic imidates to allylic amides. Tetrahedron Lett 38 8837-8840... 

Cohen F, Overman LE (1998) Planar-chiral cyclopalladated ferrocenyl amines and imines as enantioselective catalysts for allylic imidate rearrangements. Tetrahedron Asymmetry 9 3213-3222... 

The asymmetric aza-Claisen rearrangement of allyl imidates, (86) (87), has been shown to be catalysed by homochiral cationic palladium(II) complexes, and a series of enantiopure cyclopalladated ferrocenyl amines and imines have been... 

Overman and co-workers carried out extensive studies on Pd(II)-catalyzed asymmetric allylic rearrangement of allylic imidates to form enantioenriched allylic amides. They achieved 97 % ee as the best result by the reaction of the allylic imidate 612 using the cyclopalladated ferrocenyl oxazoline 613 having elements of planar chirality as a catalyst precursor, and discussed the mechanism of the reaction [220]. 

With chiral cyclopalladated ferrocenyl compounds, allylic imidates were rearranged to allylic amides. Their enantioselectivities were dramatically improved by using catalysts containing planar chiral elements such as Pd, O, N, C, and Si. 

A cyclopalladated ferrocenyl oxazoline 3-methoxy-3-pentyl derivative 8.12 was activated in CH2CI2 by deiodination with CFjCOOAg, for example, to give rearranged allylic amide 8.11 in a high yield and a high enantioselectivity from -allylic imidate 8.10, as shown in Eq. (8.1) [16]. 

We have recently found, albeit in only one example derived from a cyclopalladated ferrocenyl starting material, that 1,3-dienes indeed insert into the Pd-C bond of these compounds and lead to stable Ti -allylpal-ladium compounds that may be depalladated in the presence of PPhj in methanol to afford six- or eight-membered rings. ... 

Ferrocenyl-iminophosphines, chiral, synthesis, 6, 204 l-(Ferrocenyl)indenyl ligands, in Ir complexes, 7, 386 Ferrocenylketimines, cyclopalladated, synthesis, 8, 286... 

Ferrocenylimines derived from benzoylferrocene were synthesized and cyclopalladated by Bosque et The cr(GH) bonds in ferrocenyl- and bis(ferrocenyl)imines were activated in cyclopalladation reactions. Depending on the imine, five- and six-membered palladacycles were obtained. Bosque and Lopez also studied the cyclopalladation of mono- and bidentate primary ferrocenylimines. Mak / /. studied the cyclopalladation of ferrocenylimines in which the nitrogen of the imine is also substituted with a cyclic ether. Enantiopure bis(//-acetato)-bridged dimers were obtained. The insertion of diphenylacetylene was also investigated. 

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