Asymmetric Induction in Darzens Condensation by Means of (R)-5,5- Dimethyl-4-Phenyloxazolidin-2-One as an Effective Chiral Auxiliary

2007 ◽  
Vol 4 (4) ◽  
pp. 228-231 ◽  
Author(s):  
Abed Badrian ◽  
Manouchehr Mamaghani ◽  
Khalil Tabatabaeian ◽  
Hassan Valizadeh
Keyword(s):  
Chiral Auxiliary ◽  
Asymmetric Induction ◽  
Darzens Condensation

Asymmetric Induction in Darzens Condensation by Means of (R)-5,5-Dimethyl-4-phenyloxazolidin-2-one as an Effective Chiral Auxiliary.

ChemInform ◽  
2007 ◽  
Vol 38 (52) ◽  
Author(s):  
Abed Badrian ◽  
Manouchehr Mamaghani ◽  
Khalil Tabatabaeian ◽  
Hassan Valizadeh
Keyword(s):  
Chiral Auxiliary ◽  
Asymmetric Induction ◽  
Darzens Condensation

Photochemistry of 9-methylbicyclo[3.3.1]nonyl aryl ketones — A novel 1,5-disproportionation of 1,4-hydroxy biradicals and asymmetric induction using the solid-state ionic chiral auxiliary method

2005 ◽  
Vol 83 (9) ◽  
pp. 1460-1472 ◽  
Author(s):  
Shuang Chen ◽  
Brian O Patrick ◽  
John R Scheffer
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Solid State Ionic ◽  
Chiral Auxiliary ◽  
Asymmetric Induction ◽  
X Ray Crystallography ◽  
Aryl Ketones ◽  
Hydroxy Biradicals ◽  
Phenyl Ketones ◽  
State Ionic

A novel 1,5-disproportionation reaction has been discovered for 1,4-hydroxy biradicals derived from the photolysis of 9-methylbicyclo[3.3.1]nonyl phenyl ketones (1), which undergo mainly Yang cyclization both in solution and the solid state. By applying the solid-state ionic chiral auxiliary method of asymmetric synthesis to the Yang cyclization, enantiomeric excesses as high as 95% were achieved at high reaction conversions. The origin of the reaction selectivity is discussed with the help of X-ray crystallography. In addition, the solid-state photoreaction of ketone 1b was found to occur in a single crystal-to-single crystal fashion.Key words: photochemistry, 1,4-hydroxy biradical, disproportionation, asymmetric induction, ionic chiral auxiliary, single crystal-to-single crystal reaction.

ChemInform Abstract: Asymmetric Induction in the Darzens Reaction by Using an η6-Cr(CO)3 Complexed Arene as Chiral Auxiliary.

ChemInform ◽  
1987 ◽  
Vol 18 (47) ◽  
Author(s):  
C. BALDOLI ◽  
P. DEL BUTTERO ◽  
E. LICANDRO ◽  
S. MAIORANA ◽  
A. PAPAGNI
Keyword(s):  
Chiral Auxiliary ◽  
Asymmetric Induction ◽  
Darzens Reaction

Asymmetric induction in the Darzens reaction by using an η6-Cr(CO)3complexed arene as chiral auxiliary

1987 ◽  
pp. 762-764 ◽  
Author(s):  
Clara Baldoli ◽  
Paola Del Buttero ◽  
Emanuela Licandro ◽  
Stefano Maiorana ◽  
Antonio Papagni
Keyword(s):  
Chiral Auxiliary ◽  
Asymmetric Induction ◽  
Darzens Reaction

scholarly journals Investigation of a new chiral auxiliary derived chemoenzymatically from toluene: experimental and computational study

2016 ◽  
Vol 94 (10) ◽  
pp. 848-856 ◽  
Author(s):  
Ivan Šnajdr ◽  
Jordan Froese ◽  
Travis Dudding ◽  
Pavlína Horáková ◽  
Tomáš Hudlický
Keyword(s):  
Monte Carlo ◽  
Force Field ◽  
Spectral Data ◽  
Computational Study ◽  
Enantiomeric Excess ◽  
Diels Alder ◽  
Chiral Auxiliary ◽  
Asymmetric Induction ◽  
Low Levels ◽  
Insight Into

A tricyclic chiral auxiliary, prepared from the enzymatically derived cis-arene dihydrodiol metabolite of toluene, was investigated as a means of asymmetric induction in several different reactions. The auxiliary was converted to an oxaziridine, and its utility in hydroxylation, providing low levels of enantiomeric excess, was compared with that of Davis’s oxaziridine. Insight into the origin of stereoinduction in this reaction is provided and is based on computational Monte Carlo Multiple Minimum (MCMM) searches using the OPLS3 force field. The use of the auxiliary group in the alkylation of appended esters proved disappointing. Diels-Alder cycloaddition of an acrylate, derived from the auxiliary group, with cyclohexadiene furnished a mixture of diastereomeric adducts in essentially equal amounts. The adducts were separated and the corresponding enantiomeric residues were isolated with good enantiomeric excess. Evidence of reasonable levels of asymmetric induction in the above processes was lacking. Experimental and spectral data are provided for all key compounds.

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