2644-30-6Relevant academic research and scientific papers
Cyclobutadiene cobalt complexes as catalysts for insertion of diazo compounds into X–H bonds
Perekalin, Dmitry S.,Shvydkiy, Nikita V.
, p. 350 - 351 (2021/06/07)
Novel cyclobutadiene cobalt complex with labile naphthalene ligand [(C4Et4)Co(C10H8)]PF6 catalyzes the insertion of ethyl diazoacetate into X–H bonds giving the corresponding products in 15–75% yields
Tandem Palladium and Isothiourea Relay Catalysis: Enantioselective Synthesis of α-Amino Acid Derivatives via Allylic Amination and [2,3]-Sigmatropic Rearrangement
Spoehrle, Stéphanie S. M.,West, Thomas H.,Taylor, James E.,Slawin, Alexandra M. Z.,Smith, Andrew D.
supporting information, p. 11895 - 11902 (2017/09/07)
A tandem relay catalytic protocol using both Pd and isothiourea catalysis has been developed for the enantioselective synthesis of α-amino acid derivatives containing two stereogenic centers from readily accessible N,N-disubstituted glycine aryl esters and allylic phosphates. The optimized process uses a bench-stable succinimide-based Pd precatalyst (FurCat) to promote Pd-catalyzed allylic ammonium salt generation from the allylic phosphate and the glycine aryl ester. Subsequent in situ enantioselective [2,3]-sigmatropic rearrangement catalyzed by the isothiourea benzotetramisole forms syn-α-amino acid derivatives with high diastereo- and enantioselectivity. This methodology is most effective using 4-nitrophenylglycine esters and tolerates a variety of substituted cinnamic and styrenyl allylic ethyl phosphates. The use of challenging unsymmetrical N-allyl-N-methylglycine esters is also tolerated under the catalytic relay conditions without compromising stereoselectivity.
Iridium porphyrin catalyzed N-H insertion reactions: Scope and mechanism
Anding, Bernie J.,Woo, L. Keith
, p. 2599 - 2607 (2013/06/26)
Ir(TTP)CH3 catalyzed N-H insertion reactions between ethyl diazoacetate (EDA) or methyl phenyldiazoacetate (MPDA) and a variety of aryl, aliphatic, primary, and secondary amines to generate substituted glycine esters with modest to high yields. Aniline substrates generally gave yields above 80%, with up to 105 catalyst turnovers, and without slow addition of the diazo reagent. Good yields were also achieved with aliphatic amines, though higher catalyst loadings and slow addition of the amine were necessary in some cases. Primary amines reacted with EDA to generate both single- and double-insertion products, either of which could be produced selectively in high yield with the proper choice of stoichiometric ratios and reaction temperature. Notably, mixed trisubstituted amines, RN(CH2CO2Et) (CHPhCO2Me), were generated from the insertion of 1 equiv of EDA and 1 equiv of MPDA into primary amines. The N-H insertion mechanism was examined using substrate competition studies, trapping experiments, and multiple spectroscopic techniques. Substrate competition studies using pairs of amines with EDA or MPDA revealed Hammett correlations with respective slopes of ρ = 0.15 and ρ+ = -0.56 as well as kinetic isotope ratios of k H/kD = 1.0 ± 0.2 and 2.7 ± 0.2. Competitive amine binding to the iridium center was demonstrated by kinetics and equilibrium binding studies. Equilibrium binding constants ranged from 102 to 105. Monitoring the reaction by absorption spectroscopy revealed a transient metalloporphyrin complex. The lifetime of this species was dependent on the nature of the amine substrate, which suggests that the catalytic cycle proceeds through a metal-ylide intermediate.
Process for preparing pyrazole functionalized benzodiazepinones
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Page/Page column 28, (2009/08/18)
The present invention provides innovative strategies for synthesizing pyrazole ring-functionalized benzodiazepinones. Alternative intermediates and high conversion strategies for forming alpha-aminobenzophenone intermediates involve a combination of aromatic acylation, displacement of electronegative leaving groups with amine, and then N-displacement strategies to produce the desired alpha-aminobenzophenone with primary amine functionality. Reaction strategies are then provided for converting alpha-aminobenzophenones to alpha-aminoamidobenzophenone intermediates with high yield and convenient reaction strategies. These alpha-aminoamidobenzophenone intermediates are then converted into benzodiazepinones. These benzodiazepinones are then converted to pyrazole ring functionalized benzodiazepinones through a series of innovative intermediates and/or reaction strategies.
On the Conformation of Fused Five-Membered Heterocyclic Rings Derived from the Intramolecular Oxime Olefin Cycloaddition Reaction
Hassner, Alfred,Maurya, Rakesh,Friedman, Oded,Gottlieb, Hugo E.,Padwa, Albert,Austin, David
, p. 4539 - 4546 (2007/10/02)
Thermal intramolecular oxime olefin cycloaddition of α-allylamino aldoximes and ketoximes 4 led stereospecifically to formation of oxadiazabicyclooctanes 6.The presence of heteroatoms in these bicyclic fused 5-membered rings permits for the first t
