Chiral Mono- and Bidentate Ligands Derived from D-Mannitol and Their Application in Rhodium(I)-Catalyzed Asymmetric Hydrogenation Reactions

Abstract

The new monodentate phosphoramidites 8a−g and bidentate phospholanes 13a−e are prepared in an ex-chiral-pool synthesis from D-mannitol. Chiral diols 7a−g, obtained via nucleophilic ring opening of bis(epoxides) 6a−b, are the key intermediates for the production of both classes of ligands. Treatment of 8a−g or 13a−e with [PdCl 2 (COD)] or [Rh(COD) 2 ][-SO 3 CF 3 ] yield the corresponding Pd (10a, 10f, 15a) and Rh compounds (9a−g and 14a−e), respectively. The C 2 symmetry of the complexes in the solid state is demonstrated by X-ray structure investigations performed on 10a, 10f and 15a. Sur-

Synthesis of Chiral Heterocyclic Phosphines for Application in Asymmetric Catalysis

“…In contrast to the synthesis of DuPHOS-type Later on the groups of Zhang [120], RajanBabu [121] and Rieger [122] extended this methodology to the synthesis of O-isopropylidene protected bis(phospholanes). Similarly as already described for the monodentate 3,4-oxysubstituted phospholanes (see Scheme 3.9) also homologues and even diastereomers of RoPHOS-type bis(phospholanes) can be (Scheme 3.45).…”

Phosphines and Related Tervalent Phosphorus Systems

“…326 The reactivity of ferrocenylmethyl alcohols, esters, ethers and amines towards nucleophiles (often secondary phosphines) has been utilised in the synthesis of new phosphines, including a tridentate system, (140), combining planar-, P-and C-chirality, 327,328 bulky phosphines, e.g., (141) and (142), 329 a ferrocenylmethylphosphine-containing polymer, 330 rac-[2-(diphenylphosphino) ferrocenyl]acetic acid and related compounds, 331 and ferrocenylphosphines bearing imidazolium groups, precursors of phosphino-carbene ligands. 332,333 The same approach has been used in the synthesis of new P,N-ferrocenyl ligands, e.g., (143) 334 and (144). 335 The established ring-opening of 1-phenyl-1-phospha[1]-ferrocenophane with phenyllithium has been applied in the synthesis of the new enantiopure phosphino-phosphinito ligand (145 Methods for the synthesis of C-functionalised arylphosphines based on the direct introduction of phosphino groups into aryl halides or tosylates, catalysed by a variety of metals, have continued to develop.…”

Chiral phosphites as ligands in asymmetric metal complex catalysis and synthesis of coordination compounds

“…Phosphite 25 derived from (S )-1,2,4-butanetriol was employed in the synthesis of complexes with an open and a half-open titanocene. 74 A novel group of phosphoramidites 26 and 27 75,76 should be pointed out.…”