28172-58-9

Upstream product

• 2835-06-5 phenylglycin 
• 15028-40-7 DL-2-phenylglycine methyl ester hydrochloride 
• 125700-07-4 (4-Methoxy-benzoylamino)-phenyl-acetic acid methyl ester 
• 28172-53-4 DL-2-(4-methoxybenzamido)-2-phenylacetic acid 
• 100-07-2 4-methoxy-benzoyl chloride 

Downstream Products

• 110315-03-2 2-(4-methoxyphenyl)-4-phenyl-4-(2,4,6-trinitrophenyl)-5(4H)-oxazolone 
• 50709-69-8 2-(2,4-dinitrophenyl)-4-isopropyl-2-phenyl-5(2H)-oxazolone 
• 110315-04-3 4-<2-(methoxycarbonyl)-4,6-dinitrophenyl>-2-(4-methoxyphenyl)-4-phenyl-5(4H)-oxazolone 
• 110698-99-2 4-[1-(4-Chloro-phenyl)-1H-[1,2,3]triazol-4-ylmethyl]-2-(4-methoxy-phenyl)-4-phenyl-4H-oxazol-5-one 
• 110699-09-7 4-Methoxy-N-(2-morpholin-4-yl-2-oxo-1-phenyl-ethyl)-benzamide 
• 110699-06-4 5-(4-Methoxy-phenyl)-2-phenyl-1H-pyrrole-3-carbaldehyde 
• 110699-11-1 3-[1-(4-Chloro-phenyl)-1H-[1,2,3]triazol-4-yl]-2-(4-methoxy-benzoylamino)-2-phenyl-propionic acid methyl ester 
• 110699-01-9 2-(4-Methoxy-phenyl)-4-phenyl-4-[1-(3-trifluoromethyl-phenyl)-1H-[1,2,3]triazol-4-ylmethyl]-4H-oxazol-5-one 
• 128732-18-3 2-(4-Methoxy-phenyl)-4-phenyl-4-(3-phenyl-isoxazol-4-ylmethyl)-4H-oxazol-5-one 

Relevant academic research and scientific papers

Chemoselective activation of sp3 vs sp2 C-H bonds with Pd(II)

The first selective coupling of a carbon nucleophile with methyl, ethyl, propyl, and butyl arenes in the absence of a directing group is described. Pd(OAc)2 double C-H activation displays remarkable selectivity for the terminal methyl sites in alkyl arenes, rather than the more commonly observed arene sp2 C-H activation. Mechanistic studies indicate the intermediacy of an azlactone dimer, obtained from oxidation with Pd(OAc)2, and are consistent with a Pd-catalyzed C-H activation vs a radical process. The observed reactivity establishes that typical reaction solvents (e.g., toluene) can readily participate in C-H activation chemistry.

Catalytic Aerobic Cross-Dehydrogenative Coupling of Azlactones en Route to α,α-Disubstituted α-Amino Acids

We developed a catalytic aerobic method to synthesize α,α-disubstituted α-amino acids through cross-dehydrogenative coupling of azlactones. Combining an iron catalyst with a bisoxazolidine ligand resulted in high catalytic performance, and cross-coupling with an indole proceeded smoothly under aerobic conditions. A wide variety of α-aryl and aliphatic amino acid derived azlactones were applied to the present catalysis. In addition, a quaternary carbon could be constructed using oxindole and benzofuranone under aerobic conditions.

Amino Acid Schiff Base Bearing Benzophenone Imine As a Platform for Highly Congested Unnatural α-Amino Acid Synthesis

Unnatural α-amino acids are invaluable building blocks in synthetic organic chemistry and could upgrade the function of peptides. We developed a new mode for catalytic activation of amino acid Schiff bases, serving as a platform for highly congested unnatural α-amino acid synthesis. The redox active copper catalyst enabled efficient cross-coupling to construct contiguous tetrasubstituted carbon centers. The broad functional group compatibility highlights the mildness of the present catalysis. Notably, we achieved successive β-functionalization and oxidation of amino acid Schiff bases to afford dehydroalanine derivatives bearing tetrasubstituted carbon. A three-component cross-coupling reaction of an amino acid Schiff base, alkyl bromides, and styrene derivatives demonstrated the high utility of the present method. The diastereoselective reaction was also achieved using menthol derivatives as a chiral auxiliary, delivering enantiomerically enriched α-amino acid bearing α,β-continuous tetrasubstituted carbon. The synthesized highly congested unnatural α-amino acid could be derivatized and incorporated into peptide synthesis.

Rational Design of 2-Substituted DMAP- N-oxides as Acyl Transfer Catalysts: Dynamic Kinetic Resolution of Azlactones

A novel concept that conversion of chiral 2-substituted DMAP into its DMAP-N-oxide could significantly enhance the catalytic activity and still be used as an acyl transfer catalyst is presented. A new type of chiral 2-substituted DMAP-N-oxides, derived from l-prolinamides, has been rationally designed, facilely synthesized, and applied in the dynamic kinetic resolution of azlactones. Using simple MeOH as the nucleophile, various l-amino acid derivatives were produced in high yields (up to 98% yield) and enantioselectivities (up to 96% ee). Furthermore, α-deuterium labeled l-phenylalanine derivative was also obtained. Experiments and DFT calculations revealed that in 2-substituted DMAP-N-oxide, the oxygen atom acted as the nucleophilic site and the N-H bond functioned as the H-bond donor. High enantioselectivity of the reaction was governed by steric factors, and the addition of benzoic acid reduced the activation energy by participating in the construction of a H-bond bridge. The theoretical chemical study indicated that only when attack directions of the chiral catalyst were fully considered could the correct calculation results be obtained. This work paves the way for the utilization of the C2 position of the pyridine ring and the development of chiral 2-substituted DMAP-N-oxides as efficient acyl transfer catalysts.

Strategy for Catalytic Chemoselective Cross-Enolate Coupling Reaction via a Transient Homocoupling Dimer

A new strategy, a transient homocoupling dimer strategy, for direct catalytic oxidative cross-enolate coupling reactions is developed. Cross-enolate coupling products bearing a (contiguous) tetrasubstituted carbon center were obtained chemoselectively without the need for stoichiometric amounts of strong bases/metal oxidants, and thus, the present catalysis provides a general method for the synthesis of unnatural α,α-disubstituted amino acid motifs. The distinct transformation of azlactone and 2-acylimidazole units highlighted the synthetic utility of the present catalysis.

Regiodivergent Enantioselective γ-Additions of Oxazolones to 2,3-Butadienoates Catalyzed by Phosphines: Synthesis of α,α-Disubstituted α-Amino Acids and N,O-Acetal Derivatives

Phosphine-catalyzed regiodivergent enantioselective C-2- and C-4-selective γ-additions of oxazolones to 2,3-butadienoates have been developed. The C-4-selective γ-addition of oxazolones occurred in a highly enantioselective manner when 2-aryl-4-alkyloxazol-5-(4H)-ones were employed as pronucleophiles. With the employment of 2-alkyl-4-aryloxazol-5-(4H)-ones as the donor, C-2-selective γ-addition of oxazolones took place in a highly enantioselective manner. The C-4-selective adducts provided rapid access to optically enriched α,α-disubstituted α-amino acid derivatives, and the C-2-selective products led to facile synthesis of chiral N,O-acetals and γ-lactols. Theoretical studies via DFT calculations suggested that the origin of the observed regioselectivity was due to the distortion energy that resulted from the interaction between the nucleophilic oxazolide and the electrophilic phosphonium intermediate.

Synthesis of di- and tri-substituted imidazole-4-carboxylates via PBu3-mediated [3+2] cycloaddition

Some new di- and trisubstituted imidazole-4-carboxylates were prepared from amidoacetic acids 3 in the present report. The key step to establish such imidazole- 4-carboxylates stemmed from the PBu3-mediated [3+2] cycloaddition between in situ-generated Δ2-oxazolinone 4 and ethyl cyanoformate6. Our results indicated that trisubstituted imidazoles 7-20 were afforded in better yields than those of disubstituted imidazoles 21-27. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications1 to view the free supplemental file. Copyright Taylor & Francis Group, LLC.

Inhibition of the human proteasome by imidazoline scaffolds

The proteasome has emerged as the primary target for the treatment of multiple myeloma. Unfortunately, nearly all patients develop resistance to competitive-type proteasome inhibitors such as bortezomib. Herein, we describe the optimization of noncompetit

Dynamic kinetic resolution of azlactones catalyzed by chiral Bronsted acids

Chiral Bronsted acids have been shown for the first time to catalyze the dynamic kinetic resolution of azlactones. 3,3'-Bis-(9-anthryl)-BINOL phosphoric acid 3c is particularly effective in the case of 4-aryl-substituted substrates, producing 85-92% ee's.

Br?nsted acid catalyzed dynamic kinetic resolution of azlactones for the synthesis of aryl glycine derivatives

The dynamic kinetic resolution of C4-aryl azlactones with alcohols was investigated by employing Br?nsted acid catalysis. The reaction provided an efficient complementary approach to access chiral aryl glycine derivatives with excellent yields (up to 99%)