Control of Diastereoselectivity by Solvent Effects in the Addition of Grignard Reagents to Enantiopuret-Butylsulfinimine:  Syntheses of the Stereoisomers of the Hydroxyl Derivatives of Sibutramine

2005 ◽  
Vol 7 (13) ◽  
pp. 2599-2602 ◽  
Author(s):  
Bruce Z. Lu ◽  
Chris Senanayake ◽  
Nansheng Li ◽  
Zhengxu Han ◽  
Roger P. Bakale ◽  
...  
Keyword(s):  
Solvent Effects ◽  
Grignard Reagents ◽  
Derivatives Of

scholarly journals Synthesis of new derivatives of copper complexes of Josiphos family ligands for applications in asymmetric catalysis

2014 ◽  
Vol 4 (7) ◽  
pp. 1997-2005 ◽  
Author(s):  
R. Oost ◽  
J. Rong ◽  
A. J. Minnaard ◽  
S. R. Harutyunyan
Keyword(s):  
Asymmetric Catalysis ◽  
Copper Complexes ◽  
Grignard Reagents ◽  
Aromatic Ketones ◽  
Asymmetric Catalytic ◽  
Catalytic Addition ◽  
Derivatives Of

New derivatives of copper complexes of Josiphos family ligands have been prepared and studied in asymmetric catalytic addition of Grignard reagents to enones, enoates and aromatic ketones.

Solvent effects on the chemical shifts of halogenated derivatives of diphenyl sulphone, dibenzothiophene and dibenzothiophene 5,5-dioxide

1990 ◽  
pp. 2071-2074 ◽  
Author(s):  
Angela R. Suárez ◽  
Margarita C. Briñón ◽  
María M. de Bertorello ◽  
Manuel González Sierra ◽  
Pedro Joseph-Nathan
Keyword(s):  
Solvent Effects ◽  
Chemical Shifts ◽  
Derivatives Of

Silyl Derivatives of the Mixed Sandwiches Cyclopentadienyl Manganese Benzene and Cyclopentadienyl Manganese Biphenyl, CpMn(C6H6) and CpMn(C6H5-Ph)

1997 ◽  
Vol 52 (9) ◽  
pp. 1037-1042 ◽  
Author(s):  
Max Herberhold ◽  
Thomas Hofmann ◽  
Stefanie Weinberger ◽  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectroscopy ◽  
Membered Ring ◽  
Grignard Reagents ◽  
Sandwich Complexes ◽  
Subsequent Reaction ◽  
Silyl Derivatives ◽  
Magnesium Halide ◽  
Derivatives Of

Mixed manganese sandwich complexes containing a silyl-substituted cyclopentadienyl ring, e. g. (η5 - C5H4 - R)Mn(η6- C6H6) (3a - c) and (η5- C5H4 - R)Mn(η6- C6H5 - Ph) (4a - c); (R = SiMe3 (a), Si2Me5 (b) and SiMe2tBu (c)), were obtained in low yield via intermediates {(η5 - C5H4 - R)MnCl} and their reaction with phenyl Grignard reagents. Use of the 4-trimethylsilyl-phenyl magnesium halide in the reaction with the intermediate {CpMnCl} led to complexes with silylsubstituted arene rings, CpMn(η6 - C6H5 - R′) (5a) and CpMn(η6 -R′ - C6H5 - C6H5 - R′) (6a); (R′ = SiMe3 (a)). Dilithiation of CpMn6H6) (1) and subsequent reaction with a chlorosilane gave (η5-C5H4 - R)Mn(η6 - C6H5 - R′) (7a,b); (R = R′ = SiMe3 (a), Si2Me5 (b)). A cyclophane 8 in which five- and six-membered ring are linked through a -Me2Si-SiMe2- bridge was obtained using 1,2-dichloro-tetramethyldisilane. The mixed manganese sandw ich complexes were thoroughly characterized by 1H , 13C, 29Si and 55Mn NMR spectroscopy. The 55Mn spectra can be used to detect low-yield side-products.

Reaction of Grignard reagents with β-dicarbonyl compounds. II. Synthesis of β-hydroxyketones from 2,4-pentanedione

1967 ◽  
Vol 45 (15) ◽  
pp. 1761-1765 ◽  
Author(s):  
P. Canonne ◽  
L. C. Leitch
Keyword(s):  
Grignard Reagents ◽  
Magnesium Bromide ◽  
Dicarbonyl Compounds ◽  
Girard’S Reagent ◽  
Derivatives Of ◽  
By Products

Several new β-hydroxyketones having the formula CH3R′C(OH)CH2COCH3 have been prepared by the action of Grignard reagents on 2,4-pentanedione. With benzyl-, o-xylyl-, p-xylyl-, 3,4-dimethylbenzyl-, 2,5-dimethylbenzyl-, 3,5-dimethylbenzyl-, and α-naphthylmethyl-magnesium chlorides, 60 to 75% yields of the β-hydroxyketones were obtained. Phenyl-, p-tolyl-, and p-trifluoromethylphenyl-magnesium bromide and 2,4-dimethylbenzylmagnesium chloride gave lower yields, whereas with α-naphthylmagnesium bromide no β-hydroxyketone was formed. The β-hydroxyketones were separated from non-ketonic by-products by means of Girard's reagent T or P. Solid derivatives of the β-hydroxyketones could not be prepared.

Reactions of Norbornen-7-one with Organolithium Reagents

1971 ◽  
Vol 49 (13) ◽  
pp. 2223-2228 ◽  
Author(s):  
F. R. S. Clark ◽  
J. Warkentin
Keyword(s):  
Solvent Effects ◽  
Grignard Reagents ◽  
Organolithium Reagents

Alkyllithium reagents (RLi: R = methyl, n-butyl, t-butyl) add to norbornen-7-one either without stereochemical preference (R = n-butyl) or with syn attack favored. This addition selectivity is qualitatively the same as that shown by corresponding alkylmagnesium reagents but competition from reduction is much less important in the case of alkyllithium reagents.Phenyllithium and vinyllithium add preferentially from the anti face, although the corresponding Grignard reagents add selectively from the syn face. Possible causes of the stereoselectivities are considered. Solvent effects on the stereochemistry of addition are small.

How to drive imine–enamine tautomerism of pyronic derivatives of biological interest – A theoretical and experimental study of substituent and solvent effects

2010 ◽  
Vol 13 (5) ◽  
pp. 553-560 ◽  
Author(s):  
Anissa Amar ◽  
Hacene Meghezzi ◽  
Abdou Boucekkine ◽  
Racheddine Kaoua ◽  
Bellara Kolli
Keyword(s):  
Experimental Study ◽  
Solvent Effects ◽  
Biological Interest ◽  
Derivatives Of

Synthesis and structure of 3-arylazo derivatives of ortho-carborane

2020 ◽  
Vol 44 (25) ◽  
pp. 10199-10202
Author(s):  
Akim V. Shmalko ◽  
Sergei A. Anufriev ◽  
Marina Yu. Stogniy ◽  
Kyrill Yu. Suponitsky ◽  
Igor B. Sivaev
Keyword(s):  
Grignard Reagents ◽  
Derivatives Of

A series of B-substituted arylazo derivatives of ortho-carborane 3-XC6H4-NN-1,2-C2B10H11 (X = p-NMe2, p-OMe, o-Me) were synthesized by reaction of its diazonium derivative [3-N2-o-C2B10H11][BF4] with the corresponding Grignard reagents.

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