34209-90-0Relevant academic research and scientific papers
Asymmetric Organocatalysis and Continuous Chemistry for an Efficient and Cost-Competitive Process to Pregabalin
Bernardi, Luca,Carlone, Armando,Cobley, Christopher J.,Mccormack, Peter,Oruganti, Srinivas,Warr, Tony
, p. 2795 - 2805 (2021/12/13)
Herein, we present the scale up development of an innovative synthetic process to pregabalin. The process is underpinned by two enabling technologies critical to its success; continuous chemistry allowed a safe and clean production of nitroalkene, and asymmetric organocatalysis gave access to the chiral intermediate in an enantioenriched form. Crucial to the success of the process was the careful development of a continuous process to nitroalkene and optimization of the organocatalyst and of the reaction conditions to attain remarkably high turn-over frequency in the catalytic asymmetric reaction. Successful recycle of the organocatalysts was also developed in order to achieve a cost-competitive process.
A Nickel-Bisdiamine Porous Organic Polymer as Heterogeneous Chiral Catalyst for Asymmetric Michael Addition to Aliphatic Nitroalkenes
Buendia, Mikkel B.,Kegn?s, S?ren,Kramer, S?ren
supporting information, p. 5506 - 5512 (2020/10/23)
We report a polystyrene-incorporated chiral nickel(II)-bisdiamine complex, which is accessible on gram-scale. This metal complex functions as a heterogeneous catalyst for the enantioselective Michael addition between malonates and aliphatic nitroalkenes,
CuI-Catalysed Enantioselective Alkyl 1,4-Additions to (E)-Nitroalkenes and Cyclic Enones with Phosphino-Oxazoline Ligands
Shin, Minkyeong,Gu, Minji,Lim, Sung Soo,Kim, Min-Jae,Lee, JuHyung,Jin, HyeongGyu,Jang, Yun Hee,Jung, Byunghyuck
supporting information, p. 3122 - 3130 (2018/07/06)
Catalytic enantioselective conjugate additions of simple alkyl groups to nitroalkenes or cyclic enones that result in the formation of tertiary C–C bonds are described. For these stereoselective addition reactions, new chiral phosphino-oxazoline ligands w
Organocatalytic Enantioselective Transfer Hydrogenation of β-Amino Nitroolefins
Ferraro, Antonino,Bernardi, Luca,Fochi, Mariafrancesca
supporting information, p. 1561 - 1565 (2016/10/13)
The asymmetric organocatalytic transfer hydrogenation of β-acylamino and β-tert-butyloxycarbonylamino nitroolefins has been successfully realised in excellent enantioselectivities and yields (up to >99% ee, 97% yield) with a simple thiourea catalyst and a Hantzsch ester as hydrogen source, giving a direct access to enantiomerically pure β-amino nitroalkanes. (Figure presented.).
Useful extensions of the henry reaction: Expeditious routes to nitroalkanes and nitroalkenes in aqueous media
Chandrasekhar, Sosale,Shrinidhi, Annadka
, p. 3008 - 3018 (2014/10/16)
The products of the Henry nitroaldol reaction from nitromethane and several aldehydes were reduced to the corresponding nitroalkanes with (n-Bu) 3SnH in water under microwave irradiation (80 °C/10 min), or dehydrated to the corresponding nitroalkenes with K2CO3 in water (generally 0-5 °C/20 min). Both "one-pot" reactions occur in excellent yields across a range of aliphatic and aromatic (including heteroaromatic) substrates. It seems likely that the deoxygenation of the nitroaldols occurs via coordination of an oxygen atom of the nitro group with a tin atom, which facilitates hydride delivery in the transition state. The elimination of water from the nitroaldols in mild base is likely driven by the stability of the conjugated nitroalkene products. The elimination required workup with 2 N HCl, which likely displaces a nitroalkane-nitroalkene equilibrium towards the latter. These extensions of the Henry reaction lead to products not easily obtained otherwise.
Enantioselective Michael addition of 1,3-dicarbonyl compounds to a nitroalkene catalyzed by chiral squaramides-a key step in the synthesis of pregabalin
Baran, Rastislav,Veverkova, Eva,Skvorcova, Andrea,Sebesta, Radovan
, p. 7705 - 7711 (2013/11/06)
Asymmetric organocatalytic 1,4-additions provide access to a large number of biologically relevant compounds. Chiral squaramides efficiently catalyse enantioselective Michael addition of 1,3-dicarbonyl compounds to aliphatic nitroalkenes. The resulting γ-
TRIAZOLIUM CARBENE CATALYSTS AND PROCESSES FOR ASYMMETRIC CARBON-CARBON BOND FORMATION
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Page/Page column 31-32, (2012/02/02)
Provided herein are chiral triazolium catalysts useful for asymmetric C-C bond formation and processes for their preparation. Also provided are synthetic reactions in which these catalysts are used, in particular, in asymmetric C-C bond formation.
Solvent-free organocatalytic Michael addition of diethyl malonate to nitroalkenes: The practical synthesis of Pregabalin and γ-nitrobutyric acid derivatives
Liu, Jin-Ming,Wang, Xin,Ge, Ze-Mei,Sun, Qi,Cheng, Tie-Ming,Li, Run-Tao
experimental part, p. 636 - 640 (2011/03/19)
A highly enantioselective synthesis of Pregabalin 1 hydrochloride with good overall yield (44%) and enantioselectivity (98% ee) was described. The key step is an asymmetric Michael addition of equivalent of diethyl malonate and nitroalkene under solvent-f
A simple organocatalytic enantioselective synthesis of pregabalin
Bassas, Oriol,Huuskonen, Juhani,Rissanen, Kari,Koskinen, Ari M.P.
experimental part, p. 1340 - 1351 (2009/07/26)
This paper describes a new procedure for the enantioselective synthesis of the important anticonvulsant drug Pregabalin, which shows biological properties as the (S) enantiomer only. The key step of the synthetic sequence is the Michael addition reaction of Meldrum's acid to a nitroalkene mediated by a quinidine derived thiourea. A variety of novel catalysts bearing different groups at the thiourea moiety were synthesized and tested. The most successful catalyst that incorporates a trityl substituent provided up to 75 % ee of (S)- 4. The conjugate addition reaction was carried out on a multigram scale with low loadings of catalyst (10 mol-%). Moreover, the catalyst can be recycled showing the same capability in chemical yield and asymmetric induction. Then, hydrogenation of nitroalkane 4 followed by decarboxylation of diacid 5 provides Pregabalin hydrochloride in 59% overall yield. Enantioenrichment by crystallization of the free amino acid 1 improves the (S)/(R) enantiomeric ratio to 9:1. ? Wiley-VCII Verlag GmbH & Co. KGaA.
Catalytic asymmetric intermolecular stetter reaction of heterocyclic aldehydes with nitroalkenes: Backbone fluorination improves selectivity
DiRocco, Daniel A.,Oberg, Kevin M.,Dalton, Derek M.,Rovis, Tomislav
supporting information; experimental part, p. 10872 - 10874 (2009/12/03)
(Chemical Equation Presented) The catalytic asymmetric intermolecular Stetter reaction of heterocyclic aldehydes and nitroalkenes has been developed. We have identified a strong stereoelectronic effect on catalyst structure when a fluorine substituent is
