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Diamine Ligand (diamine + ligand)
Selected AbstractsA Highly Effective Bis(sulfonamide),Diamine Ligand: A Unique Chiral Skeleton for the Enantioselective Cu-Catalyzed Henry ReactionCHEMISTRY - A EUROPEAN JOURNAL, Issue 28 2010Wei Jin A skeleton in the closet! As a unique chiral skeleton, the newly developed bis(sulfonamide),diamine, which contains both diamine and bis(sulfonamide) moieties, was a highly effective ligand for the asymmetric Cu(OAc)2 -catalyzed Henry reaction between nitromethane and aldehydes with a low catalyst loading at room temperature (see scheme). Both aliphatic and aromatic aldehydes gave excellent enantioselectivities of up to 99,%,ee. [source] Applications of Ruthenium Hydride Borohydride Complexes Containing Phosphinite and Diamine Ligands to Asymmetric Catalytic Reactions.CHEMINFORM, Issue 38 2005Rongwei Guo Abstract For Abstract see ChemInform Abstract in Full Text. [source] Simple Chiral Diaminobinaphthyl Dilithium Salts for Intramolecular Catalytic Asymmetric Hydroamination of Amino-1,3-dienesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Julia Deschamp Abstract Simple and easily accessible chiral lithium amide salts are reported as efficient (pre)catalysts for the diastereo- [up to (E:Z)=92:8] and enantioselective [up to 72% ee (E)] hydroamination/cyclisation of conjugated primary aminodienes. These chiral lithium salts are straightforwardly prepared by in situ combination of an N -substituted (R)-(+)-1,1,-binaphthyl-2,2,-diamine ligand and a commercial methyllithium solution. Information on the solid-state structure of these salts was obtained by X-ray analysis of a single crystal. [source] Asymmetric Lithiation of Boron Trifluoride-Activated Aminoferrocenes: An Experimental and Computational InvestigationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010Costa Metallinos Abstract Tertiary aminoferrocenes complexed to boron trifluoride (BF3) are shown to undergo asymmetric lithiation with alkyllithiums in the presence of bulky chiral 1,2-diaminocyclohexane ligands. This reaction represents the first BF3 -activated asymmetric lithiation of a prochiral aromatic amine and the first such transformation to be mediated by a chiral diamine other than (,)-sparteine. The process provides rapid access to a broad range of enantiomerically enriched 2-substituted-1-aminoferrocenes, including derivatives with uncommon substitution patterns that are of interest in catalysis. The enantioselectivity of the process is high enough (87:13 to 91:9 er) to allow for isolation of single enantiomers of several products after simple recrystallization as either the free aminoferrocenes or their ammonium fluoroborate salts. Both antipodes of the planar chiral 2-substituted-1-aminoferrocene products are accessible, as confirmed by single crystal X-ray diffraction analysis of two compounds with opposite relative stereochemistry. Single-point calculation of thirty-two different transition states of the reaction at the M06-2X/6-311+g(2d,2p) level produced a computational model that correctly predicted both the sense and extent of chiral induction. Three factors appeared to play important roles in determining enantioinduction during lithiation of BF3 -complexed tertiary aminoferrocenes: (i) the maintenance of a highly organized eight-membered ring transition state; (ii) the existence of a strong Li,,,F contact which placed the chiral diamine ligand in close proximity to the ferrocene substrate; (iii) the orientation of the sterically demanding N -alkyl groups of the chiral diamine additives, either away or towards, the aminoferrocene and the alkyllithium. The model may serve as a predictive tool for the rational design of new ligands for this and related asymmetric lithiations. [source] Synthesis and Cytotoxicity of Enantiomerically Pure [1,2-Diamino-1-(4-fluorophenyl)-3-methylbutane]platinum(II) ComplexesCHEMMEDCHEM, Issue 6 2006Anja Dullin Abstract A series of leaving group derivatives of enantiomerically pure [1,2-diamino-1-(4-fluorophenyl)-3-methylbutane]platinum(II) complexes were synthesized and tested for cytotoxicity. The enantiomeric purity was determined by 1H,NMR spectroscopy on the final diamines after derivation with (1R)-myrtenal. For coordination to platinum, the diamines were reacted with K2PtI4. The treatment of diiodoplatinum(II) complexes (4F-Ph/iProp-PtI2) with Ag2SO4 resulted in the sulfatoplatinum(II) complexes (4F-Ph/iProp-PtSO4), which can be easily transformed to dichloroplatinum(II) complexes (4F-Ph/iProp-PtCl2) with 2,n HCl. The importance of the leaving groups and the configuration at the diamine ligand on the antiproliferative effects was evaluated on the hormone-dependent MCF-7 and the hormone-independent MDA-MB 231 breast cancer cell lines as well as the LNCaP/FGC prostate cancer cell line. (R,R)-4F-Ph/iProp-PtCl2 was identified as the most active platinum(II) complex. The 3-methyl group increased antiproliferative effects relative to the [1,2-diamino-1-(4-fluorophenyl)butane]platinum(II) complexes described in an earlier study. [source] | ||||||||||