14231-57-3Relevant articles and documents
Enantioselective radical C–H amination for the synthesis of β-amino alcohols
Nakafuku, Kohki M.,Zhang, Zuxiao,Wappes, Ethan A.,Stateman, Leah M.,Chen, Andrew D.,Nagib, David A.
, p. 697 - 704 (2020/07/02)
Asymmetric, radical C–H functionalizations are rare but powerful tools for solving modern synthetic challenges. Specifically, the enantio- and regioselective C–H amination of alcohols to access medicinally valuable chiral β-amino alcohols remains elusive. To solve this challenge, a radical relay chaperone strategy was designed, wherein an alcohol was transiently converted to an imidate radical that underwent intramolecular H-atom transfer (HAT). This regioselective HAT was also rendered enantioselective by harnessing energy transfer catalysis to mediate selective radical generation and interception by a chiral copper catalyst. The successful development of this multi-catalytic, asymmetric, radical C–H amination enabled broad access to chiral β-amino alcohols from a variety of alcohols containing alkyl, allyl, benzyl and propargyl C–H bonds. Mechanistic experiments revealed that triplet energy sensitization of a Cu-bound radical precursor facilitates catalyst-mediated HAT stereoselectivity, enabling the synthesis of several important classes of chiral β-amines by enantioselective, radical C–H amination. [Figure not available: see fulltext.]
Chemo- and Diastereoselective Synthesis of N-Propargyl Oxazolidines through a Copper-Catalyzed Domino A3 Reaction
Zhang, Yazhen,Huang, Liliang,Li, Xiaoyang,Wang, Le,Feng, Huangdi
supporting information, p. 5046 - 5055 (2019/05/10)
Herein we describe a highly chemoselective A3-coupling/annulation of amino alcohols, formaldehyde, two kinds of aldehydes and alkynes, catalyzed by copper(II). This cascade reaction, employing readily available materials, provides a new and highly effective access to chiral N-propargyl oxazolidines with good diastereoselectivity (up to >20:1). In the case of ortho-substituted aromatic aldehydes, an intriguing steric effect is observed: a bulky group exhibits a remarkably adverse effect on the diastereoselectivity for the formation of the title molecule.
Green Regio- and Enantioselective Aminolysis Catalyzed by Graphite and Graphene Oxide under Solvent-Free Conditions
Acocella, Maria Rosaria,D'Urso, Luciana,Maggio, Mario,Guerra, Gaetano
, p. 1915 - 1920 (2016/07/06)
The ring-opening reactions of epoxides with amines were efficiently and regioselectively catalyzed by high-surface-area graphite and graphene oxide under metal-free and solvent-free conditions. For epoxides without aryl groups, catalytic activity was observed only for graphene oxide, and hence, the activity must have been due to its acidic groups. For styrene oxide, instead, graphite and graphene oxide exhibited rather similar catalytic activities, and hence, the activity was mainly due to activation of the electrophilic epoxide by π-stacking interactions with the graphitic π system. The described aminolysis procedure is green and cheap because the catalyst can be recovered and recycled without loss of efficiency. Moreover, these heterogeneous catalysts exert high stereoselective control in the presence of nonracemic epoxides and provide chiral β-amino alcohols with enantiomeric excess values up to 99 %.
Copper-Catalyzed Regio- and Stereoselective Ring-Opening of Cyclic Sulfamidates with Grignard Reagents assisted by Lithium Chloride
Arigala, Pitchaiah,Sadu, Venkata S.,Hwang, In-Taek,Hwang, Jin-Soo,Kim, Chul-Ung,Lee, Kee-In
, p. 2027 - 2032 (2015/06/23)
Copper-catalyzed ring-opening reactions of cyclic 1,2-sulfamidates with a wide range of Grignard reagents have been investigated. The use of lithium chloride as an additive is essential to activate CO bond cleavage. The reaction represents highly regio- and stereoselective, and thus allows for efficient synthesis of enantioenriched α-branched benzylamine derivatives. Furthermore, we demonstrated that the products are potential to be used as building blocks for the preparation of wide range of nitrogen-containing heterocycles.
Design and synthesis of enantiomeric (R)- and (S)-copper(II) and diorganotin(IV)-based antitumor agents: Their in vitro DNA binding profile, cleavage efficiency and cytotoxicity studies
Arjmand, Farukh,Muddassir, Mohd.,Yousuf, Imtiyaz
, p. 62 - 71 (2014/06/09)
New chiral reduced Schiff base ligands (R)/(S)-2-(2-hydroxy-1- phenylethylaminomethyl)phenol (L), (R)/(S)-2-(benzylamino)-2-phenylethanol (L′) and their Cu(II)/organotin(IV) complexes (1-4) were synthesized and thoroughly characterized. Preliminary in vit
Bis(phosphinite) with C2-symmetric axis; Effects on the ruthenium(II)-catalyzed asymmetric transfer hydrogenation of acetophenone derivatives
Aydemir, Murat,Durap, Feyyaz,Kayan, Cezmi,Baysal, Akin,Turgut, Ylmaz
, p. 2777 - 2784 (2013/02/22)
Chiral ruthenium catalyst systems generated in situ from [Ru(η6-p-cymene)(μ-Cl)Cl]complex and chiral Csymmetric bis(phosphinite) ligands based on amino alcohol derivatives were employed in the asymmetric transfer hydrogenation of aromatic ketones to give the corresponding optically active alcohols in high yield. The best results were obtained in the [Ru(η6-p-cymene)(μ-Cl)Cl]and (2S)-2-[benzyl(2-{benzyl[(2S)-1- [(diphenylphosphanyl)oxy]-3-phenyl propan-2-yl]amino}ethyl)amino]-3-phenylpropyl diphenylphosphinite or (2R)-2-[benzyl(2-{benzyl[(2R)-1-[(diphenylphosphanyl) oxy]-3-phenylpropan-2-yl]amino}ethyl)amino]-3-phenylpropyl diphenylphosphinite catalytic systems, which gave enantioselectivities of up to 93% ee and 99% conversion. Copyright
Pyridine containing chiral macrocycles: Synthesis and their enantiomeric recognition for amino acid derivatives
Deniz, Pinar,Turgut, Yilmaz,Togrul, Mahmut,Hosgoren, Halil
, p. 6227 - 6232 (2011/09/19)
Four novel C2-symmetric enantiomerically pure, chiral pyridine-18-crown-6 type macrocycles containing lipophilic chains at the stereogenic centers were prepared. The enantioselectivity of the new ligands toward the enantiomers of d-,l-amino acid methyl ester derivatives were also determined by 1H NMR titration method. These novel macrocycles have been showed to be strong complexing agents for d- and l-amino acid methyl ester hydrochloride salts (with Kass up to 13590 M-1 and G 0 up to 23.3 kJ mol-1 and selectivity ratio: 80:20) by 1H NMR titration methods. These macrocyclic hosts exhibited enantioselective binding towards the d-enantiomer of valine methyl ester hydrochloride with Kd/Kl up to 5.08 in CDCl3 with 0.25% CD3OD.
Reactivity of (R)-4-phenyloxazolidine-2-thione chiral auxiliary: From deprotection to heterocyclic interconversion
Monbaliu, Jean-Christophe,Tinant, Bernard,Marchand-Brynaert, Jacqueline
, p. 2459 - 2475 (2011/04/17)
Using (R)-3-benzyl-4-phenyloxazolidin-2-thione (2) as model compound, a sequence of reactions has been established that allows the chiral auxiliary deprotection to furnish a primary amine. Treatment of 2 with ethyl triflate (3b) followed by ring opening with RbI (4b) and HI elimination with DBU, in a one pot process, gave S-ethyl-N-benzyl-N-1-phenylvinylcarbamothioate (5, 95% yield) which acid hydrolysis (9) and saponification liberated benzylamine. Through a mechanistic study, we showed that the activated chiral oxazolidin-2-thione 3b is a tunable intermediate towards the corresponding oxazolidin-2-one 7, thiazolidin-2-one 8 and thiazolidin-2-thione 10. All those reactions were chemoselective and preserved the chiral center. A structural analysis of this series of heterocycles, by NMR and X-ray diffraction, has been performed. The Japan Institute of Heterocyclic Chemistry.
Mild electrochemical deprotection of N-phenylsulfonyl N-substituted amines derived from (R)-phenylglycinol
Coeffard, Vincent,Thobie-Gautier, Christine,Beaudet, Isabelle,Le Grognec, Erwan,Quintard, Jean-Paul
, p. 383 - 391 (2008/09/18)
The electrochemical reduction of N-phenylsulfonyl N-substituted amines in a protic medium under constant cathodic potential was found to be a mild desulfonylation method, which is able to challenge the chemical ones. The influence of the nature of the N-substituents was considered in order to clarify the mechanistic aspects and to evaluate the scope of the method. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Highly diastereoselective addition of organometallic reagents to a trifluoroacetaldehyde hydrazone derived from (R)-N-benzylphenylglycinol
Fries, Stéphane,Pytkowicz, Julien,Brigaud, Thierry
, p. 4761 - 4764 (2007/10/03)
Organolithium and Grignard reagents add efficiently with very high stereoselectivity (>98% de) to a trifluoroacetaldehyde hydrazone derived from (R)-N-benzylphenylglycinol. The addition proceeds on the re face of the chelated hydroxyhydrazone providing th
