62965-35-9Relevant articles and documents
Auxiliary-controlled diastereoselective synthesis of a syn C-6-epimer of the ADAM 10 inhibitor GI254023X
Nair, Shankari,Zeevaart, Jan Rijn,Hunter, Roger
, p. 90 - 102 (2020/10/08)
ADAM10 is a cell surface-expressed metalloprotease involved in various cell adhesion and proteolytic processes, in which biological studies have linked an over-expression of ADAM10 to the development and progression of various types of diseases including cancer. GI254023X is a hydroxamate metalloprotease inhibitor known for ADAM10 activity inhibition, but for which structure-activity based biological information for assessing anti-tumour and anti-inflammatory activity is lacking. In this work, an Evans’ asymmetric boron aldol reaction was used to synthesise a syn C-6-epimer of GI254023X intended for biological evaluation against the natural inhibitor.
Asymmetric Dearomative Cascade Multiple Functionalizations of Activated N-Alkylpyridinium and N-Alkylquinolinium Salts
Chen, Ying-Chun,Du, Wei,Song, Xue,Yan, Ru-Jie
supporting information, p. 7617 - 7621 (2020/10/09)
An enantioselective cascade reaction of N-alkylpyridinium and -quinolinium salts with o-hydroxybenzylideneacetones to access fused polyheterocycles through cross dienamine-mediated addition followed by trapping of the dearomatized enamine-type intermediates and aminal formation has been developed. A cascade assembly of N-benzyl-4-methylpyridinium salt and cyclic 2,4-dienones is further disclosed to give bridged frameworks via repetitive dearomatization and aromatization activation.
Novel 1,3,2-diazaphospholidines with pseudodipeptide substituents
Chuchelkin,Gavrilov,Firsin,Zimarev,Novikov,Maksimova,Shiryaev,Zheglov,Tafeenko,Chernyshev,Gavrilov
, p. 493 - 496 (2019/01/05)
Chiral 1,3,2-diazaphospholidine with pseudodipeptide substituents was prepared. This asymmetric inducer provided up to 84% ee in the Pd-catalyzed asymmetric allylic alkylation of (E)-1,3-diphenylallyl acetate with dimethyl malonate, and up to 53% ee in the Rh-catalyzed asymmetric hydrogenation of (Z)-methyl 2-acetamido-3-phenylacrylate.
A new type of L-Tertiary leucine-derived ligand: Synthesis and application in Cu(II)-catalyzed asymmetric Henry reactions
Cai, Zedong,Lan, Ting,Ma, Pengfei,Zhang, Jingfang,Yang, Qingqing,He, Wei
, (2019/08/08)
A new series of Schiff bases derived from amino acids were developed as chiral ligands for Cu(II)-catalyzed asymmetric Henry reactions. The optimum ligand 7d exhibited outstanding catalytic efficiency in the Cu(II)-catalyzed asymmetric Henry additions of four nitroalkanes to different kinds of aldehydes to produce 76 desired adducts in high yields (up to 96%) with excellent enantioselectivities, up to 99% enantiomeric excess (ee).
Highly enantioselective 1,3-dipolar cycloaddition of imino esters with benzofuranone derivatives catalyzed by thiourea?quaternary ammonium salt
Du, Ting,Li, Zhaokun,Zheng, Changwu,Fang, Guosheng,Yu, Longhui,Liu, Jun,Zhao, Gang
, p. 7485 - 7494 (2018/11/27)
Highly enantioselective 1, 3-dipolar cycloaddition of 2-arylidene-benzofuran- 3(2H)-ones with imino esters catalyzed by thiourea?quaternary ammonium salts has been developed. This reaction provides efficient construction of a range of chiral spiro[benzofuran-2,3′-pyrrolidine] in high yields (up to 99%) and with good enantioselectivities (up to 99% ee) under mild conditions.
Dynamic Kinetic Resolution of N-Protected Amino Acid Esters via Phase-Transfer Catalytic Base Hydrolysis
Yamamoto, Eiji,Wakafuji, Kodai,Furutachi, Yuho,Kobayashi, Kaoru,Kamachi, Takashi,Tokunaga, Makoto
, p. 5708 - 5713 (2018/05/30)
Asymmetric base hydrolysis of α-chiral esters with synthetic small-molecule catalysts is described. Quaternary ammonium salts derived from quinine were used as chiral phase-transfer catalysts to promote the base hydrolysis of N-protected amino acid hexafluoroisopropyl esters in a CHCl3/NaOH (aq) via dynamic kinetic resolution, providing the corresponding products in moderate to good yields (up to 99%) with up to 96:4 er. Experimental and computational mechanistic studies using DFT calculation and pseudotransition state (pseudo-TS) conformational search afforded a TS model accounting for the origin of the stereoselectivity. The model suggested π-stacking and H-bonding interactions play essential roles in stabilizing the TS structures.
Preparation method of N-alkoxy or benzyloxycarbonyl chiral amino acid
-
, (2018/03/24)
The invention provides a preparation method of N-alkoxy or benzyloxycarbonyl amino acid, particularly provides a preparation method of N-alkoxy or benzyloxycarbonyl chiral amino acid, and more particularly provides a preparation method of N-alkoxy or benzyloxycarbonyl-L-amino acid or N-alkoxy or benzyloxycarbonyl-D-amino acid. In the preparation method, a resolving agent is not required for chemical resolution, and the N-alkoxy or benzyloxycarbonyl chiral amino acid with high optical purity can be prepared. The N-alkoxy or benzyloxycarbonyl chiral amino acid is a very important medicine intermediate. According to the preparation method of the N-alkoxy or benzyloxycarbonyl-L-amino acid, provided by the invention, a reaction formula is as follows in the description, wherein R1 is an alkyl group, preferably a tert-butyl group; R2 is an azido group or an imide group, n is 0 or 1, and m is 1.
A chiral α - amino acid derivative and its preparation method (by machine translation)
-
Paragraph 0086; 0087, (2018/01/03)
The invention discloses a chiral α - amino acid derivative and its preparation method. The invention α - chiral amino acid derivatives, its structural formula shown in formula I: Its preparation method, comprises the following steps: with the carbonyl compound to the N, O - acetal of the mixture with a chiral primary uncle diamine organic small molecule catalyst, strong and weak acid mixing, reaction, to obtain the chiral α - amino acid compounds; the carbonyl compound including aldehyde and/or ketone. The invention chiral α - amino acid ester compound having a simple structure of the chiral primary uncle diamine organic small molecule catalyst catalytic, solvent-free, one-step synthesis, simple, high-efficiency. (by machine translation)
A Highly Active Polymer-Supported Catalyst for Asymmetric Robinson Annulations in Continuous Flow
Canellas, Santiago,Ayats, Carles,Henseler, Andrea H.,Pericàs, Miquel A.
, p. 1383 - 1391 (2017/08/09)
The preparation through Robinson annulation of enantiopure building blocks with both academic and industrial relevance, such as the Wieland-Miescher and Hajos-Parrish ketones, has suffered from important drawbacks, such as the need for high catalyst loading or extremely long reaction times. Here we report a heterogenized organocatalyst based on Luo's diamine for fast and broad-scope enantioselective Robinson annulation reactions. The polystyrene-supported diamine 19a enables the high-yield, highly enantioselective preparation of a wide range of chiral bicyclic enones under mild conditions, with reaction times as short as 60 min (batch) or residence times of 10 min (flow). In contrast with its homogeneous counterpart 19b, the catalytic resin 19a experiences a notable increase in catalytic activity with temperature in 2-MeTHF (a 10-fold decrease in reaction times without erosion in enantioselectivity is observed from room temperature to 55 °C). The scope of the transformation in batch mode has been illustrated with 14 examples, including examples only reported in poorly enantioenriched (22n) or in racemic form (22k). Enantiopure 22k has been used as the starting material for a straightforward formal synthesis of the antibiotic and antifeedant sesquiterpene (-)-isovelleral (24). The heterogenized catalyst 19a admits extended recycling (10 cycles) and has been used to develop the first asymmetric Robinson annulations in continuous flow. The potential of the flow process is illustrated by the large-scale preparation of the Wieland-Miescher ketone (65 mmol in 24 h of operation, TON of 117) and by a sequential flow experiment leading to a library of eight enantioenriched diketone compounds.
Chemo- and Diastereoselective N-Heterocyclic Carbene-Catalyzed Cross-Benzoin Reactions Using N-Boc-α-amino Aldehydes
Haghshenas, Pouyan,Gravel, Michel
supporting information, p. 4518 - 4521 (2016/09/28)
N-Boc-α-amino aldehydes are shown to be excellent partners in cross-benzoin reactions with aliphatic or heteroaromatic aldehydes. The chemoselectivity of the reaction and the facial selectivity on the amino aldehyde allow cross-benzoin products to be obtained in good yields and good diastereomeric ratios. The developed method is utilized as the key step in a concise total synthesis of d-arabino-phytosphingosine.
