119244-29-0

Upstream product

• 81477-94-3 N-(diphenylmethylene)glycine tert-butyl ester 
• 939-26-4 2-bromomethylnaphthyl bromide 
• 27532-96-3 glycine tert-butyl ester hydrochloride 
• 1013-88-3 Benzophenone imine 

Relevant academic research and scientific papers

Asymmetric Alkylation of tert-Butyl Glycinate Schiff Base with Chiral Quaternary Ammonium Salt under Micellar Conditions

matrix presented The asymmetric alkylation of the tert-butyl glycinate-benzophenone Schiff base 1 with various arylmethyl bromides catalyzed by O-allyl-N-(9-anthracenylmethyl)cinchonidinium bromide (2) proceeded smoothly under micellar conditions (5 equiv

Accelerating Biphasic Biocatalysis through New Process Windows

Process intensification through continuous flow reactions has increased the production rates of fine chemicals and pharmaceuticals. Catalytic reactions are accelerated through an unconventional and unprecedented use of a high-performance liquid/liquid counter current chromatography system. Product generation is significantly faster than in traditional batch reactors or in segmented flow systems, which is exemplified through stereoselective phase-transfer catalyzed reactions. This methodology also enables the intensification of biocatalysis as demonstrated in high yield esterifications and in the sesquiterpene cyclase-catalyzed synthesis of sesquiterpenes from farnesyl diphosphate as high-value natural products with applications in medicine, agriculture and the fragrance industry. Product release in sesquiterpene synthases is rate limiting due to the hydrophobic nature of sesquiterpenes, but a biphasic system exposed to centrifugal forces allows for highly efficient reactions.

Improved access to chiral tetranaphthoazepinium-based organocatalysts using aqueous ammonia as nitrogen source

The class of 3,30-diaryl substituted tetranaphthobisazepinium bromides has found wide application as highly efficient C2-symmetrical phase-transfer catalysts (PTCs, Maruoka type catalysts). Unfortunately, the synthesis requires a lar

9-Amino-(9-deoxy)cinchona alkaloid-derived new chiral phase-transfer catalysts

A new class of 9-amino-(9-deoxy)cinchona alkaloid-derived chiral phase-transfer catalysts bearing amino groups was developed by using known cinchona alkaloids as the starting materials. Due to the transformation of the 9-hydroxyl group into a 9-amino functional group, the catalytic performances were significantly improved in comparison with the corresponding first generation phase-transfer catalysts, and excellent yields (92-99%) and high enantioselectivities (87-96% ee) were achieved in the benchmark asymmetric α-alkylation of glycine Schiff base. Based on the special contribution of the amino group to the high yield and enantioselectivity, the possible catalytic mechanism was conjectured. This journal is

Design, synthesis, and application of tartaric acid derived N-spiro quaternary ammonium salts as chiral phase-transfer catalysts

A novel class of tartaric acid-derived N-spiro quaternary ammonium salts was synthesised starting from known TADDOLs. These compounds were found to catalyse the asymmetric α-alkylation of glycine Schiff bases with high enantioselectivities and in good yie

Preparation of chiral amino esters by asymmetric phase-transfer catalyzed alkylations of schiff bases in a ball mill

The asymmetric alkylation of Schiff bases under basic conditions in a ball mill was performed. The starting Schiff bases of glycine were prepared beforehand by milling protected glycine hydrochloride and benzophenone imine, in the absence of solvent. The Schiff base was then reacted with a halogenated derivative in a ball mill in the presence of KOH. By adding a chiral ammonium salt derived from cinchonidine, the reaction proceeded asymmetrically under phase-transfer catalysis conditions, giving excellent yields and enantiomeric excesses up to 75 %. Because an equimolar amount of starting material was used, purification was greatly simplified. Copyright

Investigations concerning the syntheses of TADDOL-derived secondary amines and their use to access novel chiral organocatalysts

A structurally carefully diversified library of novel TADDOL-derived chiral secondary amines was synthesized and investigated for their applicability to obtain new organocatalysts like chiral Lewis bases and chiral phase-transfer catalysts. The scope and limitations of the developed syntheses routes to access these catalysts as well their catalytic performance in different benchmark reactions were systematically investigated. The most powerful of the catalysts prepared was found to be highly useful for the phase-transfer catalyzed α-alkylation of glycine Schiff base (high yields and up to 93% ee). Georg Thieme Verlag KG Stuttgart · New York.

Highly efficient polymer supported phase-transfer catalysts containing hydrogen bond inducing functional groups

Merrifield resin supported cinchona ammonium salts bearing 2′-fluorobenzene, 2′-cyanobenzene and 2′-N-oxypyridine groups were prepared and applied to the phase-transfer catalytic alkylation of N-(diphenylmethylene)glycine tert-butyl ester for the enantios

Second-generation DBFOX ligands for the synthesis of β-substituted α-amino acids via enantioselective radical conjugate additions

(Chemical Equation Presented) A set of second-generation DBFOX ligands possessing extended aryl or benzyl-type groups was synthesized. The requisite amino alcohols were either commercially available (DBFOX/Bn) or constructed via Sharpless asymmetric amino

Polymeric chiral phase-transfer catalysts derived from cinchona alkaloids for enantioselective synthesis of α-amino acids

A series of dimeric/trimeric chiral quaternary ammonium salts derived from cinchona alkaloids were designed as efficient and practical chiral phase-transfer catalysts (PTCs). Presented are the details on the development of the dimeric PTCs for the synthesis of optically active α-amino acid derivatives and the optimization of the reaction variables suitable for the dimeric PTCs. The 1,3-phenyl- and the 2,7-naphthyl-linked dimeric PTCs showed excellent catalytic capability on the reactivity and enantioselectivity in the catalytic phase-transfer alkylation of N-(diphenylmethylene)glycine tert-butyl ester (1). A variety of α-amino acid derivatives were obtained with high enantiopurities using the dimeric PTCs, especially the 2,7-naphthyl-dimer 41, in a very practical manner.