Showing papers on "Dichlorophenylphosphine published in 2006"

Synthesis and reactivity of new chiral bicyclic phospholanes as acyl-transfer catalysts.

Abstract: [structure: see text] Synthesis of chiral phosphines 1a, 14a, and 18a as nucleophilic catalysts for anhydride activation and kinetic resolution of alcohols is described. Radical cyclization of alkenylphosphines produced the phosphabicyclooctane (PBO) core of catalysts 1a and 14a, while 18a was made by quenching a metallocycle precursor with dichlorophenylphosphine. Catalysts 1a and 14a are less reactive, while 18a is comparable to the most reactive catalysts in the PBO family. The preferred ground-state geometries of phosphine-boranes were identified using computational methods, and were correlated with the catalytic reactivity of the corresponding free phosphines.

Enantiomerically pure α-pinene derivatives from material of 65% enantiomeric purity. Part 2: C2-symmetric N,N'-3-(2α-hydroxy)pinane diimines and diamines

Abstract: The conversion of enantiomerically enriched (ee >99%) 2α-hydroxypinan-3-one and its oxime (obtained in previously described procedures∗ from α-pinene of 65% ee) into a range of derivatives with potential application in asymmetric synthesis was attempted C2-Symmetrical compounds, ligands for potential catalysts, were synthesized from 2α-hydroxypinan-3-one and either aliphatic or aromatic diamines Reduction or etherification/reduction of selected diiminodiols afforded respective diaminodiols and diaminoethers, which were further transformed into azolium salts Reactions of dipinanediaminoethers with dichlorophenylphosphine and subsequent in situ oxidation of the products afford the respective stable phosphinediamide oxides Four selected compounds were crystallographically studied

Synthesis of Symmetrical and Unsymmetrical Functionalized Arylphosphines from Chlorophosphines and Organozinc Reagents

Abstract: A stepwise procedure allowing the formation of symmetrical arylphosphines is described. It relies on the use of preformed functionalized aromatic organozinc reagents to perform arylations of chlorophosphines. Some preliminary results concerning the synthesis of unsymmetrical diarylphenylphosphines through sequential coupling of organozinc species with dichlorophenylphosphine are also reported.

31 P-NMR, 77 Se-NMR AND MASS SPECTRAL STUDIES ON SOME TRICOORDINATE P(III)-N AND TETRACOORDINATE P(V)-N SYSTEMS

Abstract: A series of aminophosphines were prepared by controlled condensation reaction between PCl 3 or PhPCl 2 and amines, and they were converted into the corresponding chalcogenides. 31 P-NMR and mass spectral data were collected for characterization of these asymmetrically substituted phosphines, and in addition, 77 Se- NMR data were collected for the phosphine selenides prepared. The spectral data revealed the importance of the dipolar structure for the heavier chalcogen atoms and the π-bond structure for the lighter ones. This study has also brought out the first examples of chiral tris(amino)phosphines and the corresponding selenides. KEY WORDS : Aminophosphines, Dichlorophenylphosphine, Chiral tris(amino)phosphines, Aminophosphine chalcogenides, 77 Se-NMR Bull. Chem. Soc. Ethiop. 2006 , 20(2), 207-218.

Synthesis of Symmetrical and Unsymmetrical Functionalized Arylphosphines from Chlorophosphines and Organozinc Reagents.

Abstract: A stepwise procedure allowing the formation of symmetrical arylphosphines is described. It relies on the use of preformed functionalized aromatic organozinc reagents to perform arylations of chlorophosphines. Some preliminary results concerning the synthesis of unsymmetrical diarylphenylphosphines through sequential coupling of organozinc species with dichlorophenylphosphine are also reported.

Method for producing menthyl phenylphosphinate

Abstract: PROBLEM TO BE SOLVED: To provide a method for readily producing menthyl phenylphosphinate by which an optically active enantiomer of the menthyl phenylphosphinate that can not be isolated conventionally can easily be separated, and the menthyl phenylphosphinate having high enantiomer selectivity (R P /S P or S P /R P ) can be produced by using a menthoxy metal species as a starting raw material. SOLUTION: The menthyl phenylphosphinate represented by general formula (I): HP(O)(OR)Ph (wherein, R is a menthyl group) is produced by reacting the menthoxy alkali metal species represented by general formula (II): ROM (wherein, R is a menthyl group; and M is an alkali metal) with dichlorophenylphosphine, and hydrolyzing the product. COPYRIGHT: (C)2006,JPO&NCIPI

Synthesis and Reactivity of New Chiral Bicyclic Phospholanes as Acyl‐Transfer Catalysts.

Abstract: [structure: see text] Synthesis of chiral phosphines 1a, 14a, and 18a as nucleophilic catalysts for anhydride activation and kinetic resolution of alcohols is described. Radical cyclization of alkenylphosphines produced the phosphabicyclooctane (PBO) core of catalysts 1a and 14a, while 18a was made by quenching a metallocycle precursor with dichlorophenylphosphine. Catalysts 1a and 14a are less reactive, while 18a is comparable to the most reactive catalysts in the PBO family. The preferred ground-state geometries of phosphine-boranes were identified using computational methods, and were correlated with the catalytic reactivity of the corresponding free phosphines.