Lewis base
Regiodivergent Lewis base promoted O to C carboxyl transfer of furanyl carbonates
... The butenolide architecture is recognized as a privileged struc- ture in synthetic chemistry, and is present in a variety of bio- logically active natural products. 1 The preparation of functionalized butenolides is ...
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Aryloxide promoted catalyst turnover in Lewis base organocatalysis
... the Lewis base isothiourea 55 to release the aryloxide, with subsequent deprotonation generating the ammonium enolate ...the Lewis base catalyst and reform the aryl ester functionality as ...
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Lewis base promoted organocatalysis : O to C carboxyl transfer reactions
... The most widely applied mode of organocatalysis may be classified as Lewis base catalysis, promoted by a species bearing a lone pair of electrons. The reaction scope is ever expanding and still remains a ...
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1) as an example for a weak Lewis base, the methyl cation
... Scheme 1: Reactions for the methyl cation affinity (MCA) of a neutral Lewis base (1a), an anionic Lewis base (1b) and pyridine (1c).A recent analysis of theoretical methods found that ...
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Lewis Base Directed Cycloaddition Reactions of 2-Pyrones and Alkynylaluminum Reagents
... Preliminary investigations into the cycloaddition of 2-pyrones and alkynyldichloroboranes 5 proved to be dis- appointing. These alkynes appeared to be unreactive at low tempertaure (78 °C) and served to decompose the py- ...
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Crystal structures of three anhydrous salts of the Lewis base 1,8 diazabicyclo[5 4 0]undec 7 ene (DBU) with the ring substituted benzoic acid analogues 4 aminobenzoic acid, 3,5 dinitrobenzoic acid and 3,5 dinitrosalicylic acid
... The Lewis base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is an alkaloid isolated from the sponge Niphates digitalis (Regalado et al., 2010) but is commonly synthesized. It finds use as a curing agent for ...
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A Mechanistic Study of the Lewis Base-Directed Cycloaddition of 2-Pyrones and Alkynylboranes
... (2) Lewis acid/base complexation of the dienophile/diene, respectively, followed by cycloaddition via a [4 + 2] ...precise Lewis acid used has a significant effect on the effective ...alternative ...
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8 Quinolinylurea
... herbicides. The structure of the 1:1 proton-transfer compound of the unsymmetrical Lewis base-substituted urea (8- quinolinyl)urea with 3,5-dinitrosalicylic acid has previously been reported (Smith et al., ...
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Small Molecule Activation with Oxo and Nitridorhenium Complexes Bearing Tridentate Chelate Ligands.
... frustrated Lewis pairs and catalyze olefin hydrogenation under mild reaction ...mild Lewis base (oxorhenium complex in our case) in which competing hydrogen activation will not completely deactivate ...
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Acylative kinetic resolution of alcohols using a recyclable polymer supported isothiourea catalyst in batch and flow
... Chiral Lewis base catalysis is most commonly applied for this transformation, with a range of excellent cata- lysts reported for the KR of many classes of secondary alco- ...the Lewis base ...
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Aquachloro(dimethyl sulfoxide κO)(pyridine 2,6 dicarboxylato κ3O,N,O′)iron(III)
... There are also reports on the reaction of H2pydc with lanthanides in the presence of a Lewis base such as pyda 2,6-diaminopyridine, which lead to the complexes H5O2Hpyda2[Ybpydc3]2H2O Ra[r] ...
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Tetrahydrothiophene tris(pentafluorophenyl)borane
... of Lewis bases to tris(pentafluorophenyl)borane for ...a Lewis base–Lewis acid adduct of tetrahydrothiophene and tris(pentafluorophenyl)borane were obtained by slow evaporation of a toluene ...
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A study of the organometallic chemistry of aluminium, gallium and idium
... complexes discussed previously have one characteristic in common, namely that they possess only one donor atom per metal centre, which is typical for Lewis base adducts of... The molecul[r] ...
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Highly Regio Selective Synthesis of β Amino Alcohol by Reaction with Aniline and Propylene Carbonate in Self Solvent System over Large Pore Zeolite Catalyst
... that Lewis acid-base pairs are respon- sible for a good activity of ...the Lewis acid and Lewis base in Na-Y zeolite together play an impor- tant role in achieving high conversion and ...
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Tetrel Bonds with -Electrons Acting as Lewis Bases –
... concern the tetrel bond if the Z-center of the Lewis acid unit is linked with the Lewis base critical 221. point or it may concern the hydrogen bond if the H-atom attractor of the Lewis[r] ...
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Against Lewis on ‘Desire as Belief’
... To see this, let’s start with DAB. Lewis proposes DAB as a formulation of weak, rather than strong, anti-Humeanism. This raises a puzzle. On the face of it, since DAB says simply that V(A)=C(A°), DAB would seem to ...
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Kraft, Franziska (2018): Expression von Sialyl Lewis a, Sialyl Lewis x, Lewis y, Galectin-3, Galectin-7, Stathmin 1 und p16 in Gewebeproben der zervikalen Dysplasie. Dissertation, LMU München: Medizinische Fakultät
... „The Lewis-Y carbohydrate antigen is expressed by many human tumors and can serve as a target for genetically redirected T cells despite the presence of soluble antigen in serum,“ Journal of immunotherapy, ...of ...
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Efficient Conversion of Glucose into
... Lewis acid sites catalyst [34-38] and Lewis acid sites own high isomerization of glucose into fructose. 204[r] ...
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Lewis and Clark and the scientific method
... Meriwether Lewis An interesting question was now to be determined; which of these rivers was the Missouri . . . which they had discribed to us as approaching very near to the Columbia river. to mistake the stream ...
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Bully/victim problems in Northern Ireland?s schools: Data from the 2000 and 2003 Young Persons? Behaviour and Attitude Surveys
... Although the international literature on the nature, prevalence, and correlates of bully/victim problems is burgeoning (see Smith, Morita, Junger-Tas, Olweus, Catalano, and Slee, 1999 for a review), it is apparent that ...
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