The effects of sulfur substitution in chiral amino thiols on the enantioselective addition of organozinc reagents to aldehydes: a novel method for estimation of free energies of dimerization in monomer–dimer equilibria

1997 ◽  
pp. 189-194 ◽  
Author(s):  
Jahyo Kang ◽  
Jin Bum Kim ◽  
Jeong Whan Kim ◽  
Duckhwan Lee
Keyword(s):  
Free Energies ◽  
Novel Method ◽  
Enantioselective Addition ◽  
Organozinc Reagents

scholarly journals Use of scaled-particle theory in the assessment of the Ph4As+/Ph4B− assumption for single ions

1979 ◽  
Vol 57 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Michael H. Abraham ◽  
Asadollah Nasehzadeh
Keyword(s):  
Free Energy ◽  
Recent Work ◽  
Scaled Particle Theory ◽  
Cavity Formation ◽  
Energy Term ◽  
Free Energies ◽  
Particle Theory ◽  
Novel Method ◽  
Energy Of Interaction ◽  
Solvent Molecules

A novel method for the assessment of the Ph4As+/Ph4B− assumption for free energies of transfer of single ions has recently been suggested by Treiner, and used by him to deduce that the assumption is not valid for transfers between water, propylene carbonate, sulpholane, dimethylsulphoxide, N-methyl-2-pyrrolidone, and perhaps also dimethylformamide. The basis of the method is the estimation of the free energy of cavity formation by scaled-particle theory, together with the hypothesis that the free energy of interaction of Ph4As+ (or Ph4B−) with solvent molecules is the same in all solvents, ΔGt0(int) = 0. It is shown in the present paper that (a) whether or not the Ph4As+/Ph4B− assumption applies to transfer to a given solvent depends on which other solvent is taken as the reference solvent in Treiner's method, (b) the calculation of the cavity free energy term by scaled-particle theory and by the theory of Sinanoglu – Reisse – Moura Ramos (SRMR) yields values so different that the method cannot be considered reliable, (c) the calculation of cavity enthalpies and entropies for Ph4As+ or Ph4B− by scaled-particle theory yields results that are chemically not reasonable, (d) the hypothesis that ΔGt0(int) = 0 conflicts with SRMR theory, and (e) the conclusions reached by Treiner are not in accord with recent work that in general supports the Ph4As+/Ph4B− assumption for solvents that are rejected by Treiner.

Synthesis of allyl-aziridines from α-halo oxime ethers and allyl zinc bromides

RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 26437-26440 ◽  
Author(s):  
Songlin Zheng ◽  
Songlin Zhang
Keyword(s):  
Grignard Reagents ◽  
Mild Conditions ◽  
Novel Method ◽  
Organozinc Reagents

A novel method for the preparation of allyl aziridines by reacting α-halo oxime ethers with allylic zinc reagents under mild conditions. Some advantages of using organozinc reagents are that they are easily prepared, non-toxic, and more selective than Grignard reagents.

Enantioselective Addition of Organozinc Reagents to Aldehydes Catalyzed by 3,3′-Bis(diphenylphosphinoyl)-BINOL

2005 ◽  
Vol 347 (11-13) ◽  
pp. 1561-1568 ◽  
Author(s):  
Manabu Hatano ◽  
Takashi Miyamoto ◽  
Kazuaki Ishihara
Keyword(s):  
Enantioselective Addition ◽  
Organozinc Reagents

Design of novel chiral N,N,O-tridentate phenanthroline ligands and their application to enantioselective addition of organozinc reagents to aldehydes

2014 ◽  
Vol 50 (87) ◽  
pp. 13224-13227 ◽  
Author(s):  
Yuki Naganawa ◽  
Tomoya Namba ◽  
Tomotaka Aoyama ◽  
Kentaro Shoji ◽  
Hisao Nishiyama
Keyword(s):  
The Novel ◽  
Tridentate Ligands ◽  
Enantioselective Addition ◽  
Organozinc Reagents ◽  
Phenanthroline Ligands

The novel chiral N,N,O-tridentate ligands (BinThro) containing binaphthyl and phenanthroline units were developed. The enantioselective organozinc addition to aldehydes was performed in the presence of BinThro (S)-1 with up to 95% ee.

Enantioselective addition of organozinc reagents to carbonyl compounds

2005 ◽  
Vol 77 (12) ◽  
pp. 2111-2119 ◽  
Author(s):  
Miguel Yus ◽  
Diego J. Ramón
Keyword(s):  
Carbonyl Compounds ◽  
Titanium Tetraisopropoxide ◽  
Enantioselective Addition ◽  
Organozinc Reagents

Different chiral camphorsulfonamide derivatives containing a hydroxy or a sulfonamido functionality, as well as chiral 1,2-hydroxysulfonamides, have been evaluated as chiral promoters in the classical enantioselective addition of dialkylzinc reagents to aldehydes in the presence of titanium tetraisopropoxide (ee up to 96 %). Surprisingly, ligands with a structure of isoborneol are able to promote the related unknown addition to ketones (ee >99 %), the best ligand being the exo-diol derived from 1,2-trans-biscamphorsulfonamidocyclohexane (HOCSAC).

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