775-15-5Relevant articles and documents
Enantioselective reduction of heterocyclic ketones with low level of asymmetry using carrots
Machado, Naira Vieira,Omori, álvaro Takeo
, p. 475 - 480 (2021/09/27)
A whole spectrum of biocatalysts for asymmetric reduction of prochiral ketones is well known including the Daucus carota root. However, this type of reaction is still challenging when pro-chiral ketones present low level of asymmetry, like heterocyclic ketones. In this work, 4,5-dihydro-3(2H)-thiophenone (1), 2-methyltetrahydrofuran-3-one (2), N-Boc-3-pyrrolidinone (3), 1-Z-3-pyrrolidinone (4) and 1-benzyl-3-pyrrolidinone (5) were studied in order to obtain the respective enantioselective heterocyclic secondary alcohols. Except for 5, the corresponding alcohols were obtained in high values of conversion and with high selectivity. In order to circumvent the low isolated yield of the corresponding chiral alcohol from 2, we observed that the use of carrots in the absence of water is feasible. Addition of co-solvents was needed to the water-insoluble ketones 3 and 4. Comparatively, baker’s yeast was used for bio reductions of 1, 3 and 4. And in terms of conversion, selectivity and work-up, the use of carrots were a more efficient biocatalyst, as well as a viable method for obtaining 5-member heterocyclic secondary alcohols.
Deoxyfluorination with CuF2: Enabled by Using a Lewis Base Activating Group
Bode, Bela E.,Chabbra, Sonia,Champion, Sue,Dawson, Daniel M.,Sood, D. Eilidh,Sutherland, Andrew,Watson, Allan J. B.
supporting information, p. 8460 - 8463 (2020/04/10)
Deoxyfluorination is a primary method for the formation of C?F bonds. Bespoke reagents are commonly used because of issues associated with the low reactivity of metal fluorides. Reported here is the development of a simple strategy for deoxyfluorination, using first-row transition-metal fluorides, and it overcomes these limitations. Using CuF2 as an exemplar, activation of an O-alkylisourea adduct, formed in situ, allows effective nucleophilic fluoride transfer to a range of primary and secondary alcohols. Spectroscopic investigations have been used to probe the origin of the enhanced reactivity of CuF2. The utility of the process in enabling 18F-radiolabeling is also presented.
Exploring Derivatives of Quinazoline Alkaloid l-Vasicine as Cap Groups in the Design and Biological Mechanistic Evaluation of Novel Antitumor Histone Deacetylase Inhibitors
Ahmad, Mudassier,Aga, Mushtaq A.,Bhat, Javeed Ahmad,Kumar, Brijesh,Rouf, Abdul,Capalash, Neena,Mintoo, Mubashir Javeed,Kumar, Ashok,Mahajan, Priya,Mondhe, Dilip Manikrao,Nargotra, Amit,Sharma, Parduman Raj,Zargar, Mohmmad Afzal,Vishwakarma, Ram A.,Shah, Bhahwal Ali,Taneja, Subhash Chandra,Hamid, Abid
, p. 3484 - 3497 (2017/05/05)
l-Vasicine is a quinazoline alkaloid with an electron dense ring and additional functionalities in its structure. Employing target oriented synthesis (TOS) based on in silico studies, molecules with significant docking scores containing different derivatives of l-vasicine as caps were synthesized. Interestingly, one molecule, i.e., 4a, which contained 3-hyroxypyrrolidine as a cap group and a six carbon long aliphatic chain as a linker was found to inhibit HDACs. 4a showed more specificity toward class I HDAC isoforms. Also 4a was found to be less cytotoxic toward normal cell lines as compared to cancer cell lines. 4a inhibited cancer cell growth and induced cell death by various mechanisms. However, 4a was found to induce cell death independent of ROS generation, and unlike many natural product based HDAC inhibitors, 4a was found to be nontoxic under in vivo conditions. Importantly, we for the first time report the possibility of using a 3-hydroxypyrrolidine cap for the synthesis of HDAC inhibitors with good potency.
Stereo-complementary bioreduction of saturated N-heterocyclic ketones
Li, Chao,Liu, Yan,Pei, Xiao-Qiong,Wu, Zhong-Liu
, p. 90 - 97 (2017/04/28)
The asymmetric bioreduction of several saturated N-heterocyclic ketones is demonstrated in a stereo-complementary fashion using the ketoreductases READH and ChKRED20 for the production of (S)- and (R)-alcohols, respectively. The reaction accepts substrates with a five-, six- or seven-membered ring, and exhibits excellent stereoselectivity when using 2-propanol as both the ultimate reducing agent and cosolvent, achieve >99% ee in the majority of cases for both enantiomers.
Preparation method of N-substituent-3-hydroxytetrahydropyrrole
-
Paragraph 0022; 0023; 0024; 0025; 0026; 0027, (2017/08/29)
The invention discloses a preparation method of N-substituent-3-hydroxytetrahydropyrrole. The preparation method takes 1,2,4-butanetriol as a starting material, and comprises the following steps: performing a halogenating reaction between the starting material and hydrogen halide to prepare an intermediate 1,4-dihalogeno-2-butanol first, and then performing a condensation reaction with primary amine RNH2 to obtain a target product, wherein R represents methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiary butyl or benzyl; the halogenating reaction is performed in the presence of an acidic catalyst, and the acidic catalyst is formic acid or acetic acid; and hydrogen halide is hydrogen chloride or hydrogen bromide. The preparation method disclosed by the invention is relatively short in synthetic route, the starting material 1,2,4-butanetriol is low in price and easy to obtain, and other materials used in the method are relatively high in safety and also relatively low in price, so that the preparation method is suitable for industrial large-scale production. Particularly, the halogenating reaction can obtain a yield of 50% or above by selection of suitable halogenating agents and catalysts.
Preparation of enantiomerically pure N-heterocyclic amino alcohols by enzymatic kinetic resolution
Tofani, Giorgio,Petri, Antonella,Piccolo, Oreste
, p. 638 - 643 (2015/08/03)
Abstract The synthesis of both enantiomers of N-benzyl-3-hydroxypyrrolidine and N-benzyl-3-hydroxypiperidine via enzymatic kinetic resolution of the corresponding racemic esters is described. Various commercially available hydrolases were studied as biocatalysts in native and immobilized form. The best results were obtained with lipases PS, AK, CAL-B and with protease Alcalase, which were active and selective for the kinetic resolutions of racemic esters (E > 100). Under optimized reaction conditions, highly enantiomerically enriched (up to 99.5% ee) resolution products were obtained. Lipase and protease showed opposite enantiopreference on the esters, allowing the preparation of both enantiomers of the target compounds. Semi-continuous reactions in column reactors with immobilized biocatalysts were also performed with high enantioselectivities. Inversion of the configuration at C(3) of N-benzyl-3-hydroxypyrrolidine was quantitatively effected in a short number of steps.
3-Hydroxypyrrolidine and (3,4)-dihydroxypyrrolidine derivatives: Inhibition of rat intestinal α-glucosidase
Carreiro, Elisabete P.,Louro, Patrícia,Adriano, Gizé,Guedes, Romina A.,Vannuchi, Nicholas,Costa, Ana R.,Antunes, Célia M.M.,Guedes, Rita C.,Burke
, p. 81 - 88 (2014/06/09)
Thirteen pyrrolidine-based iminosugar derivatives have been synthesized and evaluated for inhibition of α-glucosidase from rat intestine. The compounds studied were the non-hydroxy, mono-hydroxy and dihydroxypyrrolidines. All the compounds were N-benzylated apart from one. Four of the compounds had a carbonyl group in the 2,5-position of the pyrrolidine ring. The most promising iminosugar was the trans-3,4-dihydroxypyrrolidine 5 giving an IC50 of 2.97 ± 0.046 and a KI of 1.18 mM. Kinetic studies showed that the inhibition was of the mixed type, but predominantly competitive for all the compounds tested. Toxicological assay results showed that the compounds have low toxicity. Docking studies showed that all the compounds occupy the same region as the DNJ inhibitor on the enzyme binding site with the most active compounds establishing similar interactions with key residues. Our studies suggest that a rotation of ～90° of some compounds inside the binding pocket is responsible for the complete loss of inhibitory activity. Despite the fact that activity was found only in the mM range, these compounds have served as simple molecular tools for probing the structural features of the enzyme, so that inhibition can be improved in further studies.
Natural (-)-vasicine as a novel source of optically pure 1-benzylpyrrolidin-3-ol
Aga, Mushtaq A.,Kumar, Brijesh,Rouf, Abdul,Shah, Bhahwal A.,Andotra, Samar S.,Taneja, Subhash C.
, p. 969 - 977 (2013/06/27)
A facile and scalable methodology for the preparation of optically active (3S)-1-benzylpyrrolidin-3-ol (3), an important drug precursor, is reported. Starting from the naturally occurring alkaloid (-)-vasicine (1), a major alkaloid of the plant Adhatoda vasica, 3 was obtained in 84% overall yield (Scheme 3). Copyright
PROCESS FOR THE PREPARATION OF OPTICALLY ACTIVE N-BENZYL-3 HYDROXYPYRROLIDINES
-
Page/Page column 5, (2012/05/04)
The present invention relates to a facile, highly efficient and economical process for the preparation of optically active N-benzyl-3-hydroxypyrrolidine in high yield from a naturally occurring alkaloid vasicine. The natural alkaloid vasicine is used as a precursor of (S)—N-benzyl-3-hydroxypyrrolidine and (R)—N-benzyl-3-hydroxypyrrolidines which can easily be sourced from the medicinal plant Adatoda vasica by the method known in the art and transformed to optical isomers (R) and (S)—N-benzyl-3-hydroxypyrrolidine by the method described in the present invention.
Evolving P450pyr hydroxylase for highly enantioselective hydroxylation at non-activated carbon atom
Pham, Son Quang,Pompidor, Guillaume,Liu, Ji,Li, Xiao-Dan,Li, Zhi
supporting information; experimental part, p. 4618 - 4620 (2012/06/05)
Directed evolution of a monooxygenase to achieve very high enantioselectivity for hydroxylation at non-activated carbon atoms is demonstrated for the first time, where a triple mutant of P450pyr hydroxylase is obtained via determination of enzyme structure, iterative saturation mutagenesis, and high-throughput screening with a MS-based ee assay to increase the product ee from 53% to 98% for the hydroxylation of N-benzyl pyrrolidine to (S)-N-benzyl 3-hydroxypyrrolidine. The Royal Society of Chemistry 2012.
