- A New, Short, and Stereocontrolled Synthesis of C2-Symmetric 1,2-Diamines
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The previously unknown 5-spirocyclohexylisoimidazole has been made efficiently and simply by reaction of ammonia, glyoxal hydrate, and cyclohexanone. It is a very useful precursor for the diastereocontrolled synthesis of many C2-symmetric 1,2-diamines, a class which is important for the generation of a variety of C2-symmetric reagents and catalysts for enantioselective synthesis.
- Vemula, Rajender,Wilde, Nathan C.,Goreti, Rajendar,Corey
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supporting information
p. 3883 - 3886
(2017/07/26)
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- Enantio- and Diastereoselective Nitro-Mannich Reaction of α-Aryl Nitromethanes with Amidosulfones Catalyzed by Phase-Transfer Catalysts
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A high-yield, highly diastereo- and enantioselective nitro-Mannich reaction of α-aryl nitromethanes with amidosulfones catalyzed by a novel chiral phase-transfer catalyst, bearing multiple H-bonding donors, derived from quinine was developed. A variety of α-aryl nitromethanes and amidosulfones were investigated; and the corresponding products were obtained in excellent yields with excellent diastereo- and enantioselectivities (up to 99% yield, > 99:1 dr and >99% ee). As a demonstration of synthetic utility, the resulting β-nitroamines could be converted to corresponding meso-symmetric and optically pure unsymmetric anti-1,2-diarylethylenediamines.
- Lu, Ning,Li, Ruxu,Wei, Zhonglin,Cao, Jungang,Liang, Dapeng,Lin, Yingjie,Duan, Haifeng
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p. 4668 - 4676
(2017/05/12)
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- Synergistic copper-TEMPO catalysis of intermolecular vicinal diamination of styrenes
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A copper-catalyzed, 2,2,6,6-tetramethyl piperidine N-oxy radical-assisted intermolecular diamination of styrenes with N-fluorobenzenesulfonimide has been developed. The current protocol proved amenable to a diverse array of styrenes via cascade radical addition to readily afford synthetically useful aromatic vicinal diamines with exclusive diastereoselectivity.
- Weng, Shiue-Shien,Hsieh, Kun-Yi,Zeng, Zih-Jian,Zhang, Jia-Wei
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p. 670 - 673
(2017/01/25)
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- Lipase-catalyzed desymmetrization of meso-1,2-diaryl-1,2-diaminoethanes
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The synthesis and enzyme-catalyzed desymmetrization of meso-1,2-diaryl-1,2- diaminoethanes have been investigated. A family of aromatic meso-1,2-diamines, containing different substitution patterns in the aromatic ring, was first prepared and then desymmetrized enantioselectively using lipases as biocatalysts. Selective alkoxycarbonylation of one of the amino groups was achieved using allyl carbonates, isolating the corresponding allyl monocarbamates with moderate to high enantiomeric excess at 45 C. Candida antarctica lipase types A (CAL-A) and B (CAL-B) displayed the best activities and stereopreferences, with a dramatic influence being observed depending on the diamine structure. Non substituted and para-substituted aryldiamines led to the formation of allyl carbamates with good enantiomeric excess, using CAL-A for the less hindered substrates and CAL-B for the more hindered ones. On the other hand meta- and ortho-derivatives afforded low or negligible conversions and selectivities, respectively.
- Mendez-Sanchez, Daniel,Rios-Lombardia, Nicolas,Garcia-Granda, Santiago,Montejo-Bernardo, Jose,Fernandez-Gonzalez, Alfonso,Gotor, Vicente,Gotor-Fernandez, Vicente
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p. 381 - 386
(2014/04/03)
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- Enantioseparation of 1-arylethanols via a supramolecular chiral host consisting of N-(2-naphthoyl)-l-aspartic acid and an achiral diamine
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A supramolecular chiral host consisting of N-(2-naphthoyl)-l-aspartic acid (L-1) and meso-1,2-diphenylethylenediamine (2) is effective in enantioseparation of 1-arylethanols (up to 96% ee with 100% inclusion ratio). Here we report three different methods to prepare the inclusion crystals and discuss the chiral recognition mechanism on the basis of X-ray crystallography results.
- Kodama, Koichi,Kanno, Ayaka,Sekine, Eriko,Hirose, Takuji
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experimental part
p. 1877 - 1882
(2012/04/23)
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- A synthesis of the pseudopterosin A-F aglycone
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The synthesis of the pseudopterosin A-F aglycone from 3-methylcatechol features (a) the use of asymmetric Ireland-Claisen and aryl Claisen rearrangements to install three of the four stereocentres present in the molecule and (b) an A→AB→ABC annulation strategy using ring-closing metathesis and cationic cyclisation reactions as the key steps.
- Cooksey, John P.,Kocienski, Philip J.,Schmidt, Arndt W.,Snaddon, Thomas N.,Kilner, Colin A.
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supporting information
p. 2779 - 2785,7
(2020/07/31)
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- Design, synthesis, and biological evaluation of imidazoline derivatives as p53-MDM2 binding inhibitors
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Three series of novel imidazoline derivatives were designed, synthesized, and evaluated for their p53-MDM2 binding inhibitory activities, and anti-proliferation activities against PC3, A549, KB, and HCT116 cancer cell lines. Five of the tested compounds showed enhanced p53-MDM2 binding inhibitory potency and anti-proliferation activities in comparison with that of Nutlin-1. Flow cytometric analysis indicated that compound 7c, one of the most potent p53-MDM2 binding inhibitors with a Ki value of 0.6 μM, showed its ability to arrest cell cycle progression.
- Hu, Chunqi,Li, Xin,Wang, Weisi,Zhang, Lei,Tao, Lulu,Dong, Xiaowu,Sheng, Rong,Yang, Bo,Hu, Yongzhou
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p. 5454 - 5461
(2011/10/30)
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- Reductive coupling of aromatic oxims and azines to 1,2-diamines using Zn-MsOH or Zn-TiCl4
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The reduction of aromatic aldoxims and azines with Zn in the presence of MsOH or TiCl4 afforded N,N′-unsubstituted 1,2-diamines in one-step. The reductive coupling with Zn-MsOH gave meso 1,2-diamines selectively, whereas dl 1,2-diamines were fo
- Kise, Naoki,Ueda, Nasuo
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p. 2365 - 2368
(2007/10/03)
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- Organic chemistry: Preparative synthesis of the Corey chiral controller for enantioselective dihydroxylation of olefins
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A five-step synthesis of both enantiomers of 1,2-di(2,4,6-trimethylbenzylamino)-1,2-diphenylethane, i.e., Corey (R,R)- and (S,S)-controllers for enantioselective dihydroxylation of olefins by osmium tetroxide, starting from α,α'-diphenylglyoxime, has been developed. The key operations in the synthesis are the optical resolution of intermediate rac-1,2-diamino-1,2-diphenylethane into two enantiomers using only (R,R)-tartaric acid and the subsequent enhancement of the enantiomeric purity to >98% by crystallizations of the corresponding Schiff's bis-bases. Analysis of the enantiomeric purity of the controllers can be easily performed using 1H NMR spectra of their salts with (R)-α-methoxy-α-(trifluoromethyl)phenylacetic acid (Mosher R-acid).
- Lapitskaya,Pivnitsky
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- A simplified synthesis of (±)-1,2-Diphenyl-1,2-diaminoethane (1) from benzaldehyde and ammonia. Revision of the structures of the long-known intermediates 'hydrobenzamide' and 'amarine'
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A new pathway for the simple, stereocontrolled and economical synthesis of (±)-1 from benzaldehyde is described. The structures of two intermediates (Scheme 1) have been revised to those shown in Scheme 2.
- Corey,Kuehnle, Florian N. M.
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p. 8631 - 8634
(2007/10/03)
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- Convenient Routes to Symmetrical Benzils and Chiral 1,2-Diaryl-1,2-diaminoethanes, Useful Controllers and Probes for Enantioselective Synthesis
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Pathways for the diastereoselective preparation of chiral 1,2-diaryl-1,2-diaminoethanes from ArCOOH, ArCHO or ArBr are described.
- Corey, E. J.,Lee, Duck-Hyung,Sarshar, Sepehr
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- Synthesis of Nitrogen-Containing Macrocycles with Reductive Intramolecular Coupling of Aromatic Diimines
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Reductive intramolecular coupling of aromatic diimines is an effective method for the synthesis of a variety of nitrogen-containing macrocycles. 1,4-Diazacrown ethers 3 were effectively synthesized by intramolecular coupling of bis(imino ethers) 9 promoted by electroreduction (method A) or chemical reduction with zinc powder (method B) in the presence of methanesulfonic acid.In spite of the formation of macrocycles, the yields of 3 were relatively high.This can be explained by the formation of proton-bridged intermediates 14, in which intramolecular hydrogen bonds are formed between hydrogen and oxygen atoms of diiminium salts.Method B was more effective in the formation of 1,4-diaza-12-crown-4 derivatives 3 (n = 1) due to the template effect of Zn(2+).Optically active macrocyclic bislactones 4 were synthesized stereoselectively by reductive intramolecular coupling of bis(imino esters) 20 with zinc powder (method B).The high stereoselectivity is explained by considering proton-bridged intermediate 23.The resultant compounds 4 were transformed to optically active 1,2-diarylethylenediamines 7.Various sizes of macrocyclic bislactams 5 were synthesized by reductive intramolecular coupling of bis(imino amides) 26 with zinc powder (method B).Reduction of 5 gave the corresponding macrocyclic polyamines 6.
- Kise, Naoki,Oike, Hideaki,Okazaki, Eiichi,Yoshimoto, Masami,Shono, Tatsuya
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p. 3980 - 3992
(2007/10/02)
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- Stereochemical Studies of N,N'-Diacetyl-N,N'-dimethyl-1,2-diamino-1,2-diphenylethanes and their Mono- and Di-thio Analogues by NMR and CD Spectroscopy and by Molecular Mechanics Calculations
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The R*,R* and R*,S* diastereomers of N,N'-diacetyl-N,N'dimethyl-1,2-diamino-1,2-diphenylethane and their mono- and di-thio analogues (1-6) have been studied by 1H and 13C NMR spectroscopy and by empirical force-field calculations (MMP2-85).The NMR spectral data (chemical shifts, coupling constants and NOE) clearly show that all compounds exist in the anti conformation with the Z,Z configuration for the (thio)amide groups.The same result is obtained by the force-field calculations.Four of the compounds (2, 3, 4 and 6) are chiral and have been resolved into enantiomers by chromatography on triacetylcellulose.The CD spectra of the first eluted enantiomers of 4 and 6 could be reasonably well reproduced by calculations based on minimum energy geometries for the S,S enantiomers, whereas no agreement could be reached for 2 and 3.This agrees with the results of the force-field calculations, which predict one predominant conformer for each of 4 and 6, but significant amounts of two rotamers (both anti ZZ) for each of 2 and 3.
- Chiara, Jose Luis,Petrova, Rumyana,Simeonov, Mario,Spassov, Stefan L.,Khan, Agha Zul-Quarnain,Sandstroem, Jan
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p. 555 - 562
(2007/10/02)
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- 208. Aminierende reduktive Kupplung aromatischer Aldehyde mit niedervalenten Titan-Reagenzien zu 1,2-Diarylethylendiaminen
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In a novel McMurry-type one-pot reaction, aromatic aldehydes and secondary amines are coupled to give the N,N,N',N'-tetralkyl-1,2-diarylethylendiamines 1-22 (Table 3).To this end, a lithium dialkylamide is added to an aromatic aldehyde to give the adduct B which is then treated with 1 equiv. of TiCl4 to yield a coloured suspension of a reagent synthetically equivalent to a iminium salt (C/D in Scheme 4).After treatment with a low-valent Ti reagent which is prepared by reduction of TiCl4 with either K or, preferably, Mg, the coupling products are isolated in 23 to 81 percent yield as a 1:1 mixture of the diastereoisomers (meso- and rac-form).These are separated either by chromatography or by crystallization and characterized.
- Betschart, Claudia,Seebach, Dieter
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p. 2215 - 2231
(2007/10/02)
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- ASYMMETRIC REDUCTION OF ACETOPHENONE WITH CHIRAL REAGENTS FROM LITHIUM TETRAHYDROALUMINATE AND CHIRAL 1,2-DIOL OR DIAMINE AS STUDIED BY ALUMINUM-27 NUCLEAR MAGNETIC RESONANCE
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Asymmetric reduction of acetophenone with chiral reagents from lithium tetrahydroaluminate and (1S,2S)-1,2-diphenylethanediol or (1S,2S)-N,N'-diethyl-1,2-diphenylethanediamine in the presence or absence of added ethanol is studied by aluminum-27 NMR spectroscopy.
- Yamashita, Junzo,Tomiyama, Shigemi,Hashimoto, Harukichi,Kitahara, Keiichi,Sato, Hisao
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p. 749 - 752
(2007/10/02)
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- Thermal Rearrangements and Nucleophilic Ring Cleavage of cis-2,3-Dihydro-2,3-diphenyl-1H-1,4-diazepines
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Thermolysis of cis-2,3-dihydro-2,3-diphenyl-1H-1,4-diazepine (c2a) at 150 deg C in 5>bromobenzene solution affords quantitatively 2,3-diphenylpyridine (4a) via ring contraction and loss of one mole of ammonia.In striking contrast, on heating a 5>bromobenzene solution of cis-2,3-dihydro-2,3,6-triphenyl-1H-1,4-diazepine (c2b) to 140 deg C loss of C7H8 occurs resulting in the formation of 2,5-diphenylpyrimidine (5b) in 70percent yield.Mechanisms are proposed in order to rationalize these surprising ring contractions.Piperidine in methanol cleaved the ring of c2a*H+ producing meso-1,2-diphenyl-1,2-ethanediamine (12) and 1,3-dipiperidinopropenylium perchlorate (13).
- Quast, Helmut,Seidenspinner, Hubert-Matthias,Stawitz, Josef
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p. 1230 - 1236
(2007/10/02)
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