166655-36-3

Upstream product

• 104-88-1 4-chlorobenzaldehyde 
• 27532-96-3 glycine tert-butyl ester hydrochloride 

Downstream Products

• 1173893-39-4 2-{[1-(4-chlorophenyl)methylidene]amino}pent-4-enoic acid tert-butyl ester 
• 1310576-71-6 2-tert-butyl 4,4-dimethyl (2R,3R,5R)-5-(4-chlorophenyl)-3-(furan-2-yl)pyrrolidine-2,4,4-tricarboxylate 
• 1439552-81-4 tert-butyl 4-benzoyl-5-(4-chlorophenyl)-1H-pyrrole-2-carboxylate 

Relevant academic research and scientific papers

Synthesis of the first axially dissymmetric, Cα,α-disubstituted glycine containing a crown ether receptor, and the conformational preferences of a model peptide

Racemic and enantiomerically enriched Nα-protected methyl 6-amino-1,11-(20-crown-6)-6,7-dihydro-5H-dibenzo[a,c] -cycloheptene-6-carboxylates (Boc-[20-C-6]-Bip-OMe) (RS)-Ia, (R)-Ia and (S)-Ia have been synthesized by phase-transfer dialkylation of the 4-chlorobenzylidene derivative of glycine tert-butyl ester, with both racemic and resolved (both enantiomers) 2,2′-bis(bromomethyl)-6,6′-dimethoxy-1,1′-biphenyl being used as alkylating agents. Demethylation of the resulting (RS)-, (R)- and (S)-H-[MeO]2-Bip-OtBu, followed by esterification and Nα-Boc protection, gave (RS)-, (R)- and (S)-Boc-[HO]2-Bip-OMe. Cyclization with CS2CO3/DMF and pentaethylene glycol ditosylate afforded the crown-carrier Cα,α-disubstituted glycines (RS)-Ia, (R)-Ia and (S)-Ia, possessing only axial dissymmetry. Although (R)-Ia and (S)-Ia are enantiomerically stable in solution at 110 °C, they were obtained with only 64% ee and 48% ee, respectively, because of racemization occurring both at the demethylation/esterification and at the crown formation stages of the synthesis. Solution synthesis provided access to: (i) a number of [20-C-6]-Bip/Gly peptides up to the pentapeptide Boc-[20-C-6]-Bip-Gly-Gly-[20-C-6]-Bip-Gly-OMe (RR,SS)- and (RS,SR)-Va as a mixture of two racemic isomers, and (ii) the heptapeptide Boc-[20-C-6]-Bip-(Aib)6-OtBu (S)-VI. Conformational analysis of (S)-VI by FT-IR absorption and 1H NMR indicated a high degree of folding, with spectral patterns typical of a 310-helical peptide. The absolute configuration of the [20-C-6]-Bip residue was correlated with the CD pattern in the 200-300 nm region. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.

Cycloaddition reactions of glycine imine anions to phenylazocarboxylic esters - A new access to 1,3,5-trisubstituted 1,2,4-triazoles

Phenylazocarboxylic tert-butyl esters have recently been shown to be highly versatile building blocks due to their ability to undergo nucleophilic aromatic substitutions under mild conditions, particularly well with [18F]fluoride, and to act as precursors for aryl radicals. In this article, we now report first examples for cycloaddition reactions to phenylazocarboxylates. In a one-pot reaction with readily accessible glycine imines, a variety of highly substituted 1,2,4-triazoles could be obtained.