Ethyl, ligand structure

Based on hydrogenations of model substrates, several new ligands promise to have a similar potential as those described above. For example, Ru-Solphos (Solvias) catalysts have been shown to hydrogenate various yS-keto esters and / -diketones with ee-values up to >99% and TONs of up to 100000 (for ethyl-3-oxobutanoate) [75], while Ru-Synphos (Synkem) [107] catalysts achieved 99.4% ee at an SCR of 7000 for the hydrogenation of ethyl acetoacetate (for ligand structures, see Fig. 37.28). 

In hetero-Diels-Alder reactions, the effect of ligand structure and acidity on the catalytic activity of lanthanide catalysts has been reviewed.191 The effect of different C(2)-symmetric bisoxazolines on the zinc(II)-catalysed hetero-Diels-Alder reaction of ethyl glyoxylate with conjugated 1,3-dienes has been investigated.192 The hetero-Diels-Alder reaction 4-dimethylamino-2-phenyl-l-thiabuta-1,3 -diene with methyl acrylate and /V-cnoyloxazolidinone produces cw-3,4-disubstituted 3,4-dihydro-2//-... 

Nitrophenyl chloroformate activation. The reaction of polysaccharides with chloroformates forming reactive carbonate derivatives has often been used to link bioactive compounds, such as affinity ligands and enzymes, onto polysaccharide matrixes. It was reported that upon reaction with ethyl chloroformate cyclic carbonate as well as ethyl-carbonate structures are formed (9-13). Activation with N-succinimi-do chloroformate (14), 2,4,5-trichloroformate (14) and 4-nitrophenyl chloroformate (14, 15) reportedly led to the introduction of pending carbonate moieties. 

Fig. 1 Effect of ligand structures on ATRP activation rate constants (fcaot) with ethyl 2-bro-moisobutyrate (EtBriB) activated by Cu Br complexes in the presence of MeCN at 35 °C. N2 red, N3 black-, N4 blue-, amine/imine solid-, pyridine operv, mixed left-half solid-, linear open square-, branched filled triangle-, cyclic open circle. Reprinted with permission from American Chemical Society [41]...

The term benzodiazepine refers to a specific chemical structure. Numerous benzodiazepine-receptor ligands exist which have different structures. These include the jS-carbolines (e.g. methyl-6,7-dimethoxy-4-ethyl-jS-carboline 3-carboxylate DMCM), triazolopyridazines (e.g. CL 218872), imidazopyridines (e.g. zolpidem), and pyrazolo-quinolinones (e.g. CGS 8216). In experimental animals these compounds produce... 

TiCRjtftc) was prepared starting from Ti(NR2)4 4,5) or TiCl4 (6). The structure of the ethyl compound was elucidated by X-ray studies (7, S). The titanium atom is eight-coordinated by the sulfur atoms of the four chelating ligands and the coordination geometry closely approximates to that of a dodecahedron. 

Cobalt(III) complexes of formula cis- and trans-[Co(dtc)L4]2+ and [Co(dtc)2L2]+ where dtc = dimethyl-, diethyl- or piperidino-dithiocarbamate were prepared with phosphites P(OMe)3, P(OEt)3 and 4-ethyl-2,6,7-trioxa-l-phophabicyclo[2.2.2]octane as ligands L.1048 Whereas Co—P bonding is found, as defined in the crystal structures of each of the two forms of complexes isolated, a linkage isomer in which the phosphite is O bound was detected for the bis(dithio-carbamate) compounds. 

A further reaction of [Ir(cod)Cl]2 with 3,4-dimethylphosphaferrocene, (355), yields the trigonal-bipyramidal complex [Ir(355)3(cod)]BF4, (356). 79 (356) reacts with H2 under pressure to give [Ir(355)4H2]+. Reaction of Ir(cod)Cl]2 with o-diphenylphosphinobenzoic acid ethyl ester (dpes), (357), yields [IrCl(cod)(dpes)], where dpes is acting as a monodentate P-donor-atom ligand.580 When dpes is reacted with [Ir(cod)2]BF4, then the structurally determined... 

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