Month: September 2024

Stereoselective Process for a CCR3 Antagonist was written by Yue, Tai-Yuen;McLeod, Douglas D.;Albertson, Kevin B.;Beck, Steven R.;Deerberg, Joerg;Fortunak, Joseph M.;Nugent, William A.;Radesca, Lilian A.;Tang, Liya;Xiang, Cathie Dong. And the article was included in Organic Process Research & Development in 2006.Application of 77876-39-2 This article mentions the following:

A convergent, multikilogram, stereoselective synthesis of 1 is described. A key fragment, (S)-3-(4-fluorobenzyl)piperidine (2) was synthesized from valerolactam in three steps using our recently discovered Ir-BDPP-catalyzed asym. hydrogenation. Another key fragment, (1R,2R)-2-(benzyloxycarbonylamino)cyclohexanecarboxaldehyde (3) was synthesized from meso-hexahydrophthalic anhydride in seven steps. The stereochem. was set in the first step of this sequence via a quinidine-mediated desymmetrization of the meso-anhydride. Coupling of the fragments 2 and 3 followed by deprotection provided the penultimate 23. The active pharmaceutical ingredient (API) free base 1 was obtained by treatment of 23 with the aminothiazole fragment 4 under mild conditions. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Application of 77876-39-2).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Application of 77876-39-2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

High stereoselectivity in asymmetric Grignard cross-coupling catalyzed by nickel complexes of chiral (aminoalkylferrocenyl)phosphines was written by Hayashi, Tamio;Tajika, Masatoyo;Tamao, Kohei;Kumada, Makoto. And the article was included in Journal of the American Chemical Society in 1976.Category: chiral-phosphine-ligands This article mentions the following:

Chiral (aminoalkylferrocenyl)phosphines were effective ligands for Ni-phosphine catalyzed asym. Grignard cross-coupling reactions. In the presence of a 1:2 mixture of anhydrous NiCl2 and (S)-(R)-I (R)-(S)-I or (S)-II, the cross-coupling of PhCHMeMgCl with CH2:CHBr occurred smoothly at 0 to -20° to give 3-phenyl-1-butene of 52 ∼63% optical purity, only 4% optical yield was obtained using (R)-III as a chiral ligand. The ability of (S)-(R)-I, (R)-(S)-I and (S)-II to cause asymmetric induction was due to the complexation of the Mg atom in the Grignard reagent with the Me2N group on these (aminoalkylferrocenyl)phosphines. In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2Category: chiral-phosphine-ligands).

(R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Category: chiral-phosphine-ligands

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis