170454-96-3Relevant academic research and scientific papers
Synthesis of enantiomerically enriched indolines and tetrahydroisoquinolines from (S)-amino acid-derived chiral carbocations: An easy access to (3S,4R)-demethoxy-3-isopropyl diclofensine
Manna, Sudipta Kumar,Panda, Gautam
, p. 8318 - 8324 (2014)
Enantiomerically enriched indolines and tetrahydroisoquinolines were synthesized within 5 min to 2 h in high yields from easily accessible (S)-amino acid derived chiral carbocations. The diastereoselective Friedel-Crafts reaction is promoted by a Lewis acid (AlCl3) offering trans-diastereoselectivity. The rate of the reaction and diastereoselectivity of the product are significantly influenced by steric hindrance of the amino acids substituents and aryl groups. The methodology can be applied for the synthesis of the enantiomerically enriched bioactive scaffold (3S,4R)-demethoxy-3-isopropyl diclofensine. This journal is
Stereoretentive N-Arylation of Amino Acid Esters with Cyclohexanones Utilizing a Continuous-Flow System
Ichitsuka, Tomohiro,Komatsuzaki, Shingo,Masuda, Koichiro,Koumura, Nagatoshi,Sato, Kazuhiko,Kobayashi, Shū
supporting information, p. 10844 - 10848 (2021/05/31)
The N-arylation of chiral amino acid esters with minimal racemization is a challenging transformation because of the sensitivity of the α-stereocenter. A versatile synthetic method was developed to prepare N-arylated amino acid esters using cyclohexanones as aryl sources under continuous-flow conditions. The designed flow system, which consists of a coil reactor and a packed-bed reactor containing a Pd(OH)2/C catalyst, efficiently afforded the desired N-arylated amino acids without significant racemization, accompanied by only small amounts of easily removable co-products (i. e., H2O and alkanes). The efficiency and robustness of this method allowed for the continuous synthesis of the desired product in very high yield and enantiopurity with high space-time yield (74.1 g L?1 h?1) and turnover frequency (5.9 h?1) for at least 3 days.
Use of diphenyliodonium bromide in the synthesis of some N-phenyl-amino acids
McKerrow, Jason D.,Al-Rawi, Jasim M. A.,Brooks, Peter
experimental part, p. 1161 - 1179 (2010/04/28)
The N-phenyl methyl esters 4 of glycine, alanine, valine, leucine, isoleucine, phenylalanine, methionine, proline, serine, threonine, tyrosine, aspartic acid, and glutamic acid have been synthesized in good to excellent yields using diphenyliodonium bromide, AgNO3, and a catalytic amount of CuBr starting from the relevant amino acid ester. The chiral integrity of the amino acids 5 was maintained during these reactions, which were confirmed by the synthesis of dipeptide for each N-phenyl amino acid. The structures of the new compounds were confirmed by the analysis of their IR, 1H, and 13C NMR spectra in addition to CHN microanalysis or high-resolution mass spectrometry for the new N-phenyl amino acids 5 and the esters 4.
