Synthesis and Characterization of Novel Aminophosphine Ligands Based on Ferrocenodecaline Backbones

Preparation of Optically Active α‐Amino[3]ferrocenophanes − Building Blocks for Chelate Ligands in Asymmetric Catalysis

“…Based on early work by the Dijon group, [3] Weissensteiner et al have developed synthetic pathways to optically active chelate bis(phosphanyl) [3]ferrocenophanes, such as 2. [4,5] We had recently found an interesting complementary synthetic entry into such functionalized [3]ferrocenophane ligand systems that was based on the very readily available 1,1Ј-diacetylferrocene [6] (4) starting material. Treatment of 4 with e.g.…”

Preparation and Application of Amino Phosphine Ligands Bearing Spiro[indane-1,2′-pyrrolidine] Backbone

“…Such ligands bearing an ( ortho -diphenylphosphino)­benzylamino structure have been reported by Tsuji, Ding, Vasse, and Zheng . P,N-bidentate compounds bearing an ( o -diphenylphosphino)­benzylamino structure and extra axial or planar chirality, or a ferrocene backbone were reported by Li, Hayashi, , Alberico and Salzer, and Weissensteiner . Generally, these P,N sp 3 -bidentate compounds did not perform well in transition-metal-catalyzed asymmetric reactions.…”

Selective Syntheses of Planar-Chiral Ferrocenes

“…79 In the last few decades it has been found that Ugi's approach is applicable to related substrates, revealing almost the same stereoselectivities regarding ortho-directed lithiation and nucleophilic substitution of the amine moiety. This includes utilization of N,N-dimethyl-1-ferrocenylalkylamines and -benzylamines (85), 77,80−96 homoannularly bridged N,N-α-dimethylamino-1,2-tetramethylene ferrocenes (86), 97 88,99,116,117 It should be noted that ferrocenophanes 87−89 exhibit a reversed selectivity toward ortho-directed lithiation in comparison to Ugi's amine. Whereas (S)-77 yields upon lithiation and subsequent phosphanylation (S,R p )-78 as the major product, bridged (S)-87 gives, due to the fixed conformation, exclusively (S,S p )-91 on applying the same reaction conditions (Scheme 25).…”

“…The enantiopure starting materials 85−90 have been made available among others by resolution, 97,102,106 asymmetric reductions of ferrocenyl ketones 77,80,82,94,96,108,111,112 and imines, 105,113 asymmetric alkylation/arylation of ferrocenealdehydes, 114,115 and the use of enantiomerically pure cyclopentadienes or cyclopentadienyl ligands. 88,99,116,117 It should be noted that ferrocenophanes 87−89 exhibit a reversed selectivity toward ortho-directed lithiation in comparison to Ugi's amine. Whereas (S)-77 yields upon lithiation and subsequent phosphanylation (S,R p )-78 as the major product, bridged (S)-87 gives, due to the fixed conformation, exclusively (S,S p )-91 on applying the same reaction conditions (Scheme 25).…”

“…In the last few decades it has been found that Ugi’s approach is applicable to related substrates, revealing almost the same stereoselectivities regarding ortho-directed lithiation and nucleophilic substitution of the amine moiety. This includes utilization of N , N -dimethyl-1-ferrocenylalkylamines and -benzylamines ( 85 ), ,− homoannularly bridged N , N -α-dimethylamino-1,2-tetramethylene ferrocenes ( 86 ), − heteroannularly bridged [3] ( 87 , ,− 88 , )- and [5]ferrocenophanes ( 89 ) , as well as bisferrocenyldiamines ( 90 ) (Chart ). The enantiopure starting materials 85 – 90 have been made available among others by resolution, ,, asymmetric reductions of ferrocenyl ketones ,,,,,,, and imines, , asymmetric alkylation/arylation of ferrocenealdehydes, , and the use of enantiomerically pure cyclopentadienes or cyclopentadienyl ligands. ,,, …”