- Two Distinct Ag(I)- And Au(I)-Catalyzed Olefinations between α-Diazo Esters and N-Boc-Derived Imines
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Metal-catalyzed reactions between α-diazo esters and imines were well-known to yield aziridine derivatives exclusively. This work reports two new olefination reactions between N-Boc-derived (Boc = tert-Butyloxycarbonyl) imines and α-diazo esters with Ag(I) and Au(I) catalysts, respectively. Our mechanistic studies reveal that these new olefinations involve an initial attack of diazo esters on metal/imine complexes to form Mannich-addition intermediates, which subsequently afford α-aryl-β-aminoacrylates via a Roskamp reaction, or to form β-aryl-β-aminoacrylates via the formation of silver carbenes.
- Kardile, Rahul Dadabhau,Liu, Rai-Shung
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p. 6452 - 6456
(2019/09/06)
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- Ni(0)-Catalyzed Three-Component Coupling Reaction of Tetrafluoroethylene and N-Sulfonyl-Substituted Imines with Silanes via Aza-Nickelacycles
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A nickel-catalyzed three-component coupling reaction of tetrafluoroethylene (TFE) and N-sulfonyl-substituted imines with silanes that furnishes a variety of fluorine-containing amines is disclosed. Stoichiometric experiments revealed that the aza-nickelac
- Shirataki, Hiroshi,Ono, Takafumi,Ohashi, Masato,Ogoshi, Sensuke
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p. 851 - 856
(2019/05/16)
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- A General Asymmetric Formal Synthesis of Aza-Baylis–Hillman Type Products under Bifunctional Catalysis
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A new organocatalytic strategy for the synthesis of enantioenriched aza-Baylis–Hillman type products via a frustrated vinylogous reaction is presented. This process proceeds under mild conditions with good yields, completed Z/E selectivity and excellent e
- Frías, María,Carrasco, Ana Cristina,Fraile, Alberto,Alemán, José
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supporting information
p. 3117 - 3121
(2017/12/26)
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- Direct Mannich-Type Reactions Promoted by Frustrated Lewis Acid/Br?nsted Base Catalysts
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Direct Mannich-type reactions that afford both α- and β-amino esters by the reaction of a broad range of carbonyl compounds and aldimines are disclosed. The transformation is promoted by a sterically frustrated Lewis acid/Br?nsted base pair, which is prop
- Chan, Jessica Z.,Yao, Wenzhi,Hastings, Brian T.,Lok, Charles K.,Wasa, Masayuki
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supporting information
p. 13877 - 13881
(2016/10/26)
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- Broad Spectrum Enolate Equivalent for Catalytic Chemo-, Diastereo-, and Enantioselective Addition to N-Boc Imines
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Alkynyl ketones are attractive but challenging nucleophiles in enolate chemistry. Their susceptibility to other reactions such as Michael additions and the difficulty of controlling the enolate geometry make them difficult substrates. Mannich-type reactions, which previously have not been reported using N-carbamoyl-imines with simple ketone enolates, became our objective. In this report, we describe the first direct catalytic Mannich-type reaction between various ynones and N-Boc imines, whose stereocontrol presumably derives from catalyst control of enolate geometry. This method produces α-substituted β-amino ynones with excellent chemo-, diastereo-, and enantioselectivity. The products can be readily transformed into a broad range of molecular scaffolds upon further one-step transformations, demonstrating the utility of ynones as masked synthetic equivalents for a variety of unsymmetrically substituted acyclic ketones. In particular, alkynyl alkyl ketones resolve the long-standing problem of the inability to use the enolates of unsymmetrical dialkyl ketones lacking α-branching for regio- and stereoselective reactions.
- Trost, Barry M.,Hung, Chao-I
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p. 15940 - 15946
(2016/01/09)
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- Enantioselective synthesis of diaryl aziridines using tetrahydrothiophene- based chiral sulfides as organocatalysts
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This work describes catalytic and asymmetric aziridinations (15 examples, 95-98% ee) of benzyl bromide and imines via the imino Corey-Chaykovsky reaction using (thiolan-2-yl)diarylmethanol benzyl ether as an organocatalyst. The catalyst and analogues thereof were prepared through an expeditious and efficient synthetic route featuring a double nucleophilic substitution and Shi epoxidation as key steps.
- Huang, Meng-Ting,Wu, Hsin-Yi,Chein, Rong-Jie
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p. 1101 - 1103
(2014/01/17)
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- Activation of the Si-B Linkage: Copper-Catalyzed addition of nucleophilic silicon to imines
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Activation of the Si-B bond through copper-catalyzed transmetalation quickly developed into a practical method to generate Cu-Si reagents These silicon nucleophiles cleanly add to aldehyde-derived imine electrophiles to form R-silylated amines in protic media, and no carbon-tonitrogen Brook-type rearrangement of the intermediate anion is observed. Aside from electron-withdrawing groups at the imine nitrogen atom, for example, SO2Tol and P(O)Ph2, previously delicate nitrogen substituents such as phenyl or benzhydryl are tolerated. The same protocol also allows the unprecedented addition to representative ketone-derived imines.
- Vyas, Devendra J.,Froehlich, Roland,Oestreich, Martin
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p. 2094 - 2097
(2011/06/22)
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- Structure-activity relationship study of first selective inhibitor of excitatory amino acid transporter subtype 1: 2-Amino-4-(4-methoxyphenyl)-7- (naphthalen-1-yl)-5-oxo-5,6,7,8-tetrahydro-4 H -chromene-3-carbonitrile (UCPH-101)
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The excitatory amino acid transporters (EAATs) are expressed throughout the central nervous system, where they are responsible for the reuptake of the excitatory neurotransmitter (S)-glutamate (Glu).(1)Recently, we have reported the discovery of the first subtype selective EAAT1 inhibitor 2-amino-4-(4-methoxyphenyl)-7-(naphthalen-1-yl)-5-oxo-5,6,7,8-tetrahydro-4H- chromene-3-carbonitrile (UCPH-101) (1b) and presented an introductory structure-activity relationship (SAR) study.(2)Here, we present a detailed SAR by the design, synthesis, and pharmacological evaluation of analogues 1g-1t. By comparison of potencies of 1b, 1h, and 1i versus 1j, it is evident that potency is largely influenced by the chemical nature of the R1 substituent. The study also demonstrates that any chemical change of the functional groups or a change to the parental scaffold results in the complete loss of inhibitory activity of the compounds at EAAT1. Finally, a bioavailability study of UCPH-101 determined the half-life to be 30 min in serum (rats) but also that it was not able to penetrate the blood-brain barrier to any significant degree.
- Erichsen, Mette N.,Huynh, Tri H. V.,Abrahamsen, Bjarke,Bastlund, Jesper F.,Bundgaard, Christoffer,Monrad, Olja,Bekker-Jensen, Anders,Nielsen, Christina W.,Frydenvang, Karla,Jensen, Anders A.,Bunch, Lennart
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experimental part
p. 7180 - 7191
(2010/12/25)
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- Versatile supramolecular copper(II) Complexes for Henry and Aza-Henry reactions
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Chiral supramolecular metal-organic frameworks assembled from copper complexes catalyse Henry and aza-Henry reactions of aromatic and aliphatic aldehydes and N-protected aromatic imines in high yield and good to excellent enantioselectivity. Reactions can
- Zhang, Guoqi,Yashima, Eiji,Woggon, Wolf-D.
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supporting information; scheme or table
p. 1255 - 1262
(2009/12/22)
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- Isothiourea-catalyzed enantioselective carboxy group transfer
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Transferable skills: Enantiomerically pure isothioureas promote the 0-to C-carboxyl group transfer of oxazolyl carbonates with excellent levels of enantiocontrol (see scheme). The origin of the enantioselectivity of this process was probed mechanistically and rationalized computationally.
- Joannesse, Caroline,Johnston, Craig P.,Concellon, Carmen,Simal, Carmen,Philp, Douglas,Smith, Andrew D.
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supporting information; experimental part
p. 8914 - 8918
(2010/02/28)
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- Asymmetric allylboration of acyl imines catalyzed by chiral diols
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Chiral BINOL-derived diols catalyze the enantioselective asymmetric allylboration of acyl imines. The reaction requires 15 mol % (S)-3,3′-Ph2-BINOL as the catalyst and allyldiisopropoxyborane as the nucleophile. The reaction products are obtained in good yields (75-94%) and high enantiomeric ratios (95:5-99.5:0.5) for aromatic and aliphatic imines. High diastereoselectivities (diastereomeric ratio > 98:2) and enantioselectivities (enantiomeric ratio > 98:2) are obtained in the reactions of acyl imines with crotyldiisopropoxyboranes. This asymmetric transformation is directly applied to the synthesis of Maraviroc, the selective CCR5 antagonist with potent activity against HIV-1 infection. Mechanistic investigations of the allylboration reaction including IR, NMR, and mass spectrometry studies indicate that acyclic boronates are activated by chiral diols via exchange of one of the boronate alkoxy groups with activation of the acyl imine via hydrogen bonding.
- Lou, Sha,Moquist, Philip N.,Schaus, Scott E.
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p. 15398 - 15404
(2008/09/18)
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- Diastereoselective addition of enantiopure lithium tert- butylsulfinylferrocene to imines
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(S)-terf-Butylsulfinylferrocene was submitted to ortho-metalation, and the corresponding lithium derivative was trapped by alkyl or aryl imines bearing various electron-withdrawing groups on the nitrogen atom (Ts, Dpp, Boc). New aminosulfoxides were obtai
- Grach, Guillaume,Santos, Jana Sopkova-De Oliveira,Lohier, Jean-Francois,Mojovic, Ljubica,Ple, Nelly,Turck, Alain,Reboul, Vincent,Metzner, Patrick
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p. 9572 - 9579
(2007/10/03)
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- General and facile synthesis of 1,2-amino alcohols
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Facile preparation of 1,2-amino alcohols has been achieved by the reaction of benzyloxymethyl lithium with imines, which are generated from α-amido sulfones and benzyloxymethyl lithium in situ at -78°C in THF.
- Jung, Doo Young,Ko, Chang Hong,Kim, Yong Hae
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p. 1315 - 1317
(2007/10/03)
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- Asymmetric catalytic Mannich reactions catalyzed by urea derivatives: Enantioselective synthesis of β-aryl-β-amino acids
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Highly enantioselective addition reactions between silyl ketene acetals and N-Boc aldimines are catalyzed by the thiourea-based catalyst 1c. Extraordinary scope is observed in this methodology with regard to the imine substrate, with aryl and heteroaromatic derivatives generally affording nearly quantitative yields of β-amino ester product in up to 98% enantioselectivity. Copyright
- Wenzel, Anna G.,Jacobsen, Eric N.
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p. 12964 - 12965
(2007/10/03)
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- An expeditious one-pot synthesis of diethyl N-Boc-1-aminoalkylphosphonates
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A general one-pot, purification-free synthesis of diethyl N-Boc-1-aminoalkylphosphonates has been developed. The procedure involves base-catalyzed Michael-type addition of sodium diethyl phosphite to N-Boc imines generated in situ by the action of sodium
- Klepacz, Anna,Zwierzak, Andrzej
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p. 1079 - 1080
(2007/10/03)
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