- Addition of Highly Polarized Organometallic Compounds to N-tert-Butanesulfinyl Imines in Deep Eutectic Solvents under Air: Preparation of Chiral Amines of Pharmaceutical Interest
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Highly polarized organometallic compounds of s-block elements are added smoothly to chiral N-tert-butanesulfinyl imines in the biodegradable d-sorbitol/choline chloride eutectic mixture, thereby granting access to enantioenriched primary amines after quantitatively removing the sulfinyl group. The practicality of the method is further highlighted by proceeding at ambient temperature and under air, with very short reaction times (2 min), enabling the preparation of diastereoisomeric sulfinamides in very good yields (74–98 %) and with a broad substrate scope, and the possibility of scaling up the process. The method is demonstrated in the asymmetric syntheses of both the chiral amine side-chain of (R,R)-Formoterol (96 % ee) and the pharmaceutically relevant (R)-Cinacalcet (98 % ee).
- Capriati, Vito,Cicco, Luciana,García-álvarez, Joaquín,González-Sabín, Javier,Perna, Filippo M.,Ríos-Lombardía, Nicolás,Salomone, Antonio,Vitale, Paola
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- Pd-catalyzed asymmetric allylic etherizations with oximes by chiral alkene-phosphine ligands
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Palladium-catalyzed asymmetric allylic etherizations with a variety of oximes as nucleophiles utilizing a chiral alkene-phosphine hybrid ligand have been successfully achieved for the first time to afford the optical active oxime ethers in high yields with good to excellent enantioselectivities.
- Cao, Ziping,Liu, Zhaoqun,Liu, Yilin,Du, Haifeng
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p. 6401 - 6406
(2011/10/04)
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- Catalytic asymmetric synthesis of β-sultams as precursors for taurine derivatives
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β-Sultams, biologically interesting sulfonyl analogues of β-lactams, have been prepared by an organocata-lytic asymmetric formal [2+ 2]-cycloaddition approach of non-nucleophilic imines with alkyl sulfonyl chlorides. In the case of very electron poor N-to
- Zajac, Marian,Peters, Rene
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supporting information; experimental part
p. 8204 - 8222
(2011/02/27)
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- Synthesis of highly enantiomerically enriched amines by the diastereoselective addition of triorganozincates to N-(tert-butanesulfinyl)imines
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The reaction of triorganozincates with (R)-N-(tert-butanesulfinyl) imines gives the expected α-branched sulfinamides in good to excellent yields with diastereomeric ratios of up to 98:2. The N-sulfinyl group of the products can be easily removed by acidic treatment, affording the corresponding chiral primary amines in enantiomeric excesses of up to 96%. The reactivity and the selectivity shown by the triorganozincates are different from the ones observed with the corresponding Grignard reagents, which allows, in several cases, the preparation of both enantiomers of an amine from the same imine substrate. When mixed triorganozincates are used, one can take advantage of the slow transfer rate of the methyl group to use it as a non-transferable one. Both aromatic and aliphatic aldimines, as well as activated ketimines, are good substrates for these addition reactions.
- Almansa, Raquel,Guijarro, David,Yus, Miguel
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experimental part
p. 2484 - 2491
(2009/04/11)
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- Enantioselective reductive coupling of acetylene to N-arylsulfonyl imines via rhodium catalyzed C-C bond-forming hydrogenation: (Z)-dienyl allylic amines
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The first highly enantioselective catalytic vinylation of aldimines to furnish allylic amines is reported. Exposure of aromatic and aliphatic N-arylsulfonyl aldimines 1a-12a to equal volumes of acetylene and hydrogen gas at 45 °C and ambient pressure in t
- Skucas, Eduardas,Kong, Jong Rock,Krische, Michael J.
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p. 7242 - 7243
(2008/02/08)
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- β-Silylated homopropargylic amines via the asymmetric allenylboration of aldimines
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(Chemical Equation Presented) The asymmetric synthesis of α-trimethylsilylpropargylic carbamines (7) through the addition of allenylboranes 4 to N-H aldimines is reported. The insertion of TMSCHN 2 into enantiomerically pure B-alkynyl-10-TMS-9-
- Gonzalez, Ana Z.,Soderquist, John A.
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p. 1081 - 1084
(2008/02/01)
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- Enantioselective synthesis of primary 1-(aryl)alkylamines by nucleophilic 1,2-addition of organolithium reagents to hydroxyoxime ethers and application to asymmetric synthesis of G-protein-coupled receptor ligands
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(E)-Arylaldehyde oxime ethers bearing a (1S)-2-hydroxy-1-phenylethyl or (2R)-1-hydroxy-2-phenylethyl group as a chiral auxiliary, both derived from a single precursor, methyl (R)-mandelate, underwent nucleophilic addition with organolithium reagents via six-membered chelates to give the diastereomerically enriched (R)- and (S)-adducts, respectively, which, after chiral auxiliary removal by reductive N-O bond cleavage, led to the corresponding (R)- and (S)-1-(aryl)ethylamines. This organolithium addition protocol using methyllithium was applied in an enantiodivergent fashion to the preparation of both enantiomers of 1-(2-hydroxyphenyl)ethylamine, which has been previously used as an efficient chiral auxiliary for the synthesis of natural products in this laboratory. The synthetic utility of this methodology involving diastereoselective methyl addition was demonstrated by further application to the asymmetric synthesis of a new type of calcium receptor agonist (calcimimetics), (R)-(+)-NPS R-568 and its thio analogue. Furthermore, diastereoselective vinylation was accomplished by application of the hydroxy oxime ether-based protocol using vinyllithium, which allowed the development of the enantioselective synthesis of the NK-1 receptor antagonists, (+)-CP-99,994 and (+)-CP-122,721.
- Atobe, Masakazu,Yamazaki, Naoki,Kibayashi, Chihiro
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p. 5595 - 5607
(2007/10/03)
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- Chiral oxime ethers in asymmetric synthesis. Part 4. Asymmetric synthesis of N-protected amines and β-amino acids by the addition of organometallic reagents to ROPHy/SOPHy-derived aldoximes
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Addition of organolithium or Grignard reagents to (R)- or (S)-O-(1-phenylbutyl)aldehyde oximes 1 in the presence of boron trifluoride-diethyl ether results in the formation of hydroxylamines 2 in good to excellent diastereoselectivity. Subsequent cleavage of the N-O bond with zinc-acetic acid-ultrasound, and carbamate formation, gives N-protected amines 3 in good enantiomeric purity (77-100% ee). When allylmagnesium bromide was used as the organometallic reagent, the resulting hydroxylamines were converted into β-amino acid derivatives 4 and γ-aminb alcohols 5. The Royal Society of Chemistry 1999.
- Hunt, James C. A.,Lloyd, Cephas,Moody, Christopher J.,Slawin, Alexandra M. Z.,Takle, Andrew K.
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p. 3443 - 3454
(2007/10/03)
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- Enantioselective syntheses of α-phenylalkanamines via intermediate addition of Grignard reagents to chiral hydrazones derived from (R)-(-)-2- aminobutan-1-ol
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The hydrazine (R)-(-)-28 was obtained in four steps from 2-aminobutan- 1-ol (R)-(-)-11, and reacted with benzaldehyde to give the hydrazone (R)-(- )-29. Nucleophilic addition of various alkyl Grignard reagents to the latter yielded the corresponding trisubstituted hydrazines (R,R)-30a-g in 70-89% yields and having d.e.s=100% (1H and 13C NMR). Catalytic hydrogenolysis of these hydrazines afforded the corresponding (R)(+)-α-phenylalkanamines (R)- (+)-31a-g having e.e.s=90-92% (chiral GPC).
- Bataille, Patricia,Paterne, Michel,Brown, Eric
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p. 2181 - 2192
(2007/10/03)
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- Asymmetric Addition of Butyllithium to N-Metallo Imines of Benzaldehyde
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N-Metallo imines derived from benzaldehyde such as N-aluminium imine, N-boryl imine and N-silyl imine were asymmetrically alkylated with butyllithium in the presence of chiral ligands including (-)-sparteine and proline-derived amino alcohols to give optically active 1-phenylpentyl-1-amine in up to 74percent anantiomeric excess.Polymer-supported chiral ligands were also used for the asymmetric addition.
- Itsuno, Shinichi,Sasaki, Mamiko,Kuroda, Shizue,Ito, Koichi
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p. 1507 - 1510
(2007/10/02)
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- Application of New Camphor-Derived Mercapto Chiral Auxiliaries to the Synthesis of Optically Active Primary Amines
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A series enantiomerically pure sulfinimines carrying new camphor-based mercapto chiral auxiliaries are subjected to assymetric alkylation.Such reaction offers an excellent route to the preparation of optically active primary amines.Also reported here is an unprecedented Grignard addition of a chiral sulfenimine leading to a single enantiomer of the corresponding sulfenamide and thence produced enantiopure amine after acidic aqueous workup.The chiral auxiliary can be recovered in high yield.
- Yang, Teng-Kuei,Chen, Ruey-Yuan,Lee, Dong-Sheng,Peng, Wen-Shiuan,Jiang, Yao-Zhong,et al.
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p. 914 - 921
(2007/10/02)
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- Stereoselective Addition Reactions of Chiral N-Benzylidene-p-toluenesulfinamides. Asymmetric Syntheses of β- and γ-Amino Acids
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Chiral N-benzylidene-p-toluenesulfinamides 2 were prepared by the reaction of benzonitril with alkyllithium in ether followed by (-)-l-menthyl (S)-p-tolylsulfinate.Treatment of 2 with allylmagnesium bromide in ether at 0 deg C gave the adducts (R)-7 with excellent stereoselectivity.Pure chiral sulfinamides 7 were converted into β- and γ-amino acids in four and five steps, respectively.
- Hua, Duy H.,Miao, Shou Wu,Chen, Jin Shan,Iguchi, Sadahiko
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- Enantioselective Alkylation of N-(Trimethylsilyl)benzaldehyde Imine
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N-(Trimethylsilyl)benzaldehyde imine was alkylated with chirally modified organometallic reagents to give optically active primary amines in moderate to good yields with an enantiomeric excess (e.e.) of up to 62percent.
- Itsuno, Shinichi,Yanaka, Hiromitsu,Hachisuka, Chiharu,Ito, Koichi
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p. 1341 - 1342
(2007/10/02)
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- Acyclic Stereoselection in the Alkylation of Chiral Dipole-Stabilized Organolithiums: A Self-Immolative Chirality Transfer Process for the Synthesis of Primary Amines
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A comparison of 1,3- and 1,5-asymmetric induction shows the former to have far greater selectivity in the methylation of chiral dipole-stabilized organolithiums.The asymmetric alkylation of N-benzyloxazolidinones is employed as the key step in a new synthesis of primary amines by asymmetric alkylation α to nitrogen.
- Gawley, Robert E.,Rein, Kathleen,Chemburkar, Sanjay
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p. 3002 - 3004
(2007/10/02)
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