Sedaxane (SDX) 1, isopyrazam (IZM) 2 and Solatenol™ (STL) 3 are broad-spectrum pyrazole carboxamides, which originate from novel chemical classes of fungicides. Their mode of action (MoA) is inhibition of succinate dehydrogenase (SDH), which was recognized for a long time to deliver only compounds with a narrow biological spectrum. This view changed with the market introduction of BASF's boscalid in 2003.
View Article and Find Full Text PDFSedaxane (SDX) 1, isopyrazam (IZM) 2 and Solatenol™ (STL) 3 are broad-spectrum pyrazole carboxamides, which originate from novel chemical classes of fungicides. Their mode of action (MoA) is inhibition of succinate dehydrogenase (SDH), which was recognized for a long time to deliver only compounds with a narrow biological spectrum. This view changed with the market introduction of BASF's boscalid in 2003.
View Article and Find Full Text PDFA library of monodentate phosphane ligands, each bearing a guanidine receptor unit for carboxylates, was designed. Screening of the library gave some excellent catalysts for regioselective hydroformylation of beta,gamma-unsaturated carboxylic acids. A terminal alkene, but-3-enoic acid, was hydroformylated with a linear/branched (l/b) regioselectivity up to 41.
View Article and Find Full Text PDFThis paper describes the development of a new catalytic transformation, the ruthenium-catalyzed decarbonylative arylation of cyclic 2-amino esters, which replaces the ester group with an aryl ring at the sp3 carbon center. For example, proline ester amidine 1 is converted to 2-arylpyrrolidine 3 in the presence of arylboronic acids or esters as arene donors and Ru(3)(CO)(12) as the catalyst. This process provides a rapid access to a variety of 2-arylpyrrolidines and piperidines from commercially available proline, hydroxyproline, and pipecolinate esters.
View Article and Find Full Text PDFThis paper describes a phosphine-free palladium-catalyzed method for direct C-arylation of free (N-H)-indoles and pyrroles with iodo- and bromoarene donors. Employing commercially available materials, this new and operationally simple procedure provides a rapid entry to a wide range of C-arylated (N-H)-indoles including derivatives of tryptamine. In the course of this study, a profound halide effect was uncovered, affecting both the efficiency and regioselectivity of indole arylation.
View Article and Find Full Text PDFA new ruthenium-catalyzed direct sp3 C-H to C-C bond transformation is disclosed. Specifically, a method for the alpha-arylation of cyclic amines, containing either permanent (pyridine, pyrimidine) or removable (amidine) directing groups, is described. This cross-coupling reaction involves heating amine substrates with arylboronate ester at 150 degrees C in a ketone solvent with a catalytic amount of ruthenium carbonyl [Ru3(CO)12].
View Article and Find Full Text PDFChiral 3,3'-bis(trisarylsilyl)-substituted binaphtholate rare earth metal complexes (R)-[Ln{Binol-SiAr3}(o-C6H4CH2NMe2)(Me2NCH2Ph)] (Ln = Sc, Lu, Y; Binol-SiAr3 = 3,3'-bis(trisarylsilyl)-2,2'-dihydroxy-1,1'-binaphthyl; Ar = Ph (2-Ln), 3,5-xylyl (3-Ln)) and (R)-[La{Binol-Si(3,5-xylyl)3}{E(SiMe3)2}(THF)2] (E = CH (4a), N (4b)) are accessible via facile arene, alkane, and amine elimination. They are efficient catalysts for the asymmetric hydroamination/cyclization of aminoalkenes, giving TOF of up to 840 h(-1) at 25 degrees C for 2,2-diphenyl-pent-4-enylamine (5c) using (R)-2-Y. Enantioselectivities of up to 95% ee were achieved in the cyclization of 5c with (R)-2-Sc.
View Article and Find Full Text PDFChiral binaphtholate yttrium aryl complexes are highly active and enantioselective catalysts for the asymmetric hydroamination of aminoalkenes, as well as the kinetic resolution of alpha-substituted 1-aminopent-4-enes to give trans-2,5-disubstituted pyrrolidines with good enantiomeric excess and high k(rel).
View Article and Find Full Text PDFMonomeric diolate amido yttrium complexes [Y[diolate][N(SiHMe(2))(2)](thf)(2)] can be prepared in good yield by treating [Y[N(SiHMe(2))(2)](3)(thf)(2)] with either 3,3'-di-tert-butyl-5,5',6,6'-tetramethyl-1,1'-biphenyl-2,2'-diol (H(2)(Biphen)), 3,3'-bis(2,4,6-triisopropylphenyl)-2,2'-dihydroxy-1,1'-dinaphthyl (H(2)(Trip(2)BINO)) or 3,3'-bis(2,6-diisopropylphenyl)-2,2'-dihydroxy-1,1'-dinaphthyl (H(2)(Dip(2)BINO)) in racemic and enantiopure form. The racemic complex [Y(biphen)[N(SiHMe(2))(2)](thf)(2)] dimerizes upon heating to give the heterochiral complex (R,S)-[Y(biphen)[N(SiHMe(2))(2)](thf)](2). The corresponding dimeric heterochiral lanthanum complex was the sole product in the reaction of H(2)(Biphen) with [La[N(SiHMe(2))(2)](3)(thf)(2)].
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