Neutral Rhodium(I) Aminophosphine-Phosphinite Complexes: Synthesis, Structure, and Use in Catalytic Asymmetric Hydrogenation of Activated Keto Compounds. Crystal Structure of [(S)-1-(Dicyclohexyl- phosphino)-2-(((dicyclohexylphosphino)oxy)methyl)- pyrrolidine](2,4-pentanedionato-O,O')rhodium(I)

Inversion of enantioselectivity in the platinum-catalyzed hydrogenation of substituted acetophenones

“…There are numerous examples of the inversion of ee in asymmetric hydrogenations induced by (small) variation of the structure of the ligand in homogeneous catalysis [71,72], and that of the chiral modifier in heterogeneous catalysis [66,[73][74][75]. These striking changes in the sense of enantioselection provide valuable information on the reaction mechanism.…”

Spiroketal‐Based Phosphorus Ligands for Highly Regioselective Hydroformylation of Terminal and Internal Olefins

“…Under the otherwise identical conditions, ligands 3 a and 3 d consistently afforded higher l/b values than 3 j with a biphenyl backbone, thus attesting the advantages of spiroketal backbone in this type of ligands. Remarkably, for the hydroformylation of styrene, an olefin well-known to favor the formation of the branched aldehyde in many Rh-catalyzed hydroformylation studies, [13] both 3 d and 3 j afforded preferentially the linear aldehyde with a moderate selectivity ( Table 3, entries [13][14].…”

“…In the case of longer-chain substrate 2-octene (Z/E = 4/1), the regioselectivities towards the linear aldehyde were also high for both Rh/3 a and Rh/3 d catalysts (l/b = 23.4 and 24.0, Table 5, entries 10,11). Under otherwise identical conditions, hydroformylation of these internal olfins with the biphenolbased ligand 3 j always afford-ed a lower regioselectivity than those of 3 a and 3 d, albeit with a higher activity ( Table 5, [14] or monodentate N-pyrrolylphosphines. [15] The spiroketal backbone forms a twelve-membered heterometallocyclic ring with the Rh center, and thus enforcing sufficient steric hindrance of the pyrrolyl rings around the rhodium center.…”

N-Phosphorylated Pyrrolidines: An Overview of Synthetic Approaches

“…One example is bis-N,O-phosphaneylpyrrolidines 11, obtained from (R)-pyrrolidin-2-ylmethanol (Scheme 2, A). 41,42 An excess of the dialkylchlorophosphine and prolonged reflux were required to achieve complete phosphorylation of the NH and OH groups. Gratifyingly, the yields of the target pyrrolidines were remarkably high (88-94%).…”

“…The authors noted that the enantioselectivity of the product was dependent on the nature of the aminophosphine group. 41 An additional bidentate N-(phosphaneyl)pyrrolidine ligand was synthesized from 2,2′-bipyrrolidine (12) (Scheme 2, B). 43 The starting diamine was treated with n-BuLi first, and the resulting lithium amide was reacted with chiral cyclic chlorophosphine 13 to give the bis(phospholan-1-yl)-2,2′-bipyrrolidine derivative 14 in 90% yield.…”