Search results for "Dimi"
showing 10 items of 442 documents
Enantioselective addition of terminal alkynes to N-(diphenylphosphinoyl)imines catalyzed by Zn–BINOL complexes
2012
Abstract Chiral nonracemic N-(diphenylphosphinoyl)-protected propargylic amines have been prepared by addition of terminal alkynes to N-(diphenylphosphinoyl)aldimines in the presence of dimethylzinc and 3,3′-dibromo-BINOL as catalyst. The reaction works with a variety of aromatic and heteroaromatic aldimines and with different alkynes, providing the expected products in generally good yields and enantiomeric excesses (up to 96%).
Asymmetric Synthesis of Fluorinated Monoterpenic Alkaloid Derivatives from Chiral Fluoroalkyl Aldimines via the Pauson‐Khand Reaction
2020
Stereo and regioselectivity in the phenylation of cationic allylpalladium(II) α-diimine complexes by tetraphenylborate anion
1993
The reaction of the cationic complex [Pd(4-methoxy-1,3-η3-cyclohexenyl)(py-2-CHNC6H4OMe-4)]+ (1) with BPh4− in the presence of fumaronitrile yields trans-3-methoxy-6-phenylcyclohexene (2a) and trans-4-methoxy-3-phenylcyclohexene (2b), in ca. 1 : 1 molar ratio. The trans stereochemistry of these products implies that the phenylation of the allyl ligand involves prior transfer of a phenyl group from BPh4− to the metal, followed by reductive coupling of the organic moieties. In the reactions of [Pd(η3-1,1-R1,R2-C3H3)(NN′)]+ (3) [NN′ 4-MeOH4C6NCHCHNC6H4OMe-4; py-2-CHNR (R C6H4OMe-4, Me, or CMe3), 2,2′-bipyridine (bipy); R1 H, R2 Ph, Me; R1 R2 Me; with BPh4− in the presence of …
Synthesis of Highly Substituted 2-13C-Imidazolium Salts and Metal NHC Complexes for the Investigation of Electronic Unsymmetry by NMR
2013
Complexes of unsymmetrically substituted N-heterocyclic carbenes with NMR-active metals (Ag, Hg, Pt) with or without a 13C-label in the 2-position were synthesized by aldimine cross coupling and analyzed with respect to the scalar couplings between the metal center or C2 and the other ring atoms.
ChemInform Abstract: Stereoselective Synthesis of α-Arylalkylamines by Glycosylation-Induced Asymmetric Addition of Organometallic Compounds to Imine…
2009
Arylalkylamines are of interest as building blocks for the synthesis of biologically active compounds and as chiral ligands or chiral auxiliaries in stereoselective syntheses [1]. Their stereoselective synthesis has been achieved by enantioselective reduction of ketimines using chiral reagents [2], as for example Corey’s oxaborolidines [3], or proline-derived triacyloxyborohydrides [4]. Particularly efficient asymmetric syntheses of chiral arylalkylamines have been accomplished by Noyori et al. [5] through enantioselective catalysis of hydrogen transfer reactions using a chiral 1,2-diphenyl-ethylenediamine ruthenium catalyst. Enantioselective transferhydrogenationshave also been achieved us…
Stereoselective Synthesis of α-Arylalkylamines by Glycosylation-induced Asymmetric Addition of Organometallic Compounds to Imines
2009
Arylalkylamines are of interest as building blocks for the synthesis of biologically active compounds and as chiral ligands or chiral auxiliaries in stereoselective syntheses [1]. Their stereoselective synthesis has been achieved by enantioselective reduction of ketimines using chiral reagents [2], as for example Corey’s oxaborolidines [3], or proline-derived triacyloxyborohydrides [4]. Particularly efficient asymmetric syntheses of chiral arylalkylamines have been accomplished by Noyori et al. [5] through enantioselective catalysis of hydrogen transfer reactions using a chiral 1,2-diphenyl-ethylenediamine ruthenium catalyst. Enantioselective transferhydrogenationshave also been achieved us…
Highly enantioselective zinc/binol-catalyzed alkynylation of N-sulfonyl aldimines.
2008
Cycloaddition reactions of benzothiete with azomethines
1986
Obtention de diaryl-2,3 dihydro-3,4 benzothiazines-1,3 (70%) via la cycloaddition de la thiobenzoquinone methode-1,2 (obtenue par scission thermique du benzothiete) et d'arylimines de benzaldehydes. Obtention egalement de 10% du dimere (dibenzo [b, f] dithiocinne-1,5)
ChemInform Abstract: Organocatalytic anti-Selective Mannich Reactions with Fluorinated Aldimines: Synthesis of anti-γ-Fluoroalkyl-γ-amino Alcohols.
2010
The asymmetric Mannich reaction between fluoroalkyl aldimines and aldehydes catalyzed by α,α-diphenylprolinol trimethylsilyl ether is reported. The corresponding Mannich adducts were reduced in situ to afford anti-β-alkyl-γ-fluoroalkyl-γ-amino alcohols in moderate yields and with very high diastereo- and enantioselectivities. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Arabinosylamine in Asymmetric Syntheses of Chiral Piperidine Alkaloids.
2004
The stereodifferentiating potential of arabinosyl aldimines was utilized in stereoselective syntheses of 2-substituted dehydropiperidinones and their further transformation to 2,6-cis-substituted piperidinones. The absolute configuration was proven by X-ray analysis and by the synthesis of the enantiomerically pure alkaloid (+)-dihydropinidine. The presented method offers the possibility to synthesize piperidine derivatives enantiomeric to those obtained by the application of the corresponding galactosylamine auxiliary.