scholarly journals Grignard reaction and products. V. Reduction of ketoximes to aziridines with Grignard reagents.

1976 ◽  
Vol 24 (5) ◽  
pp. 1083-1089 ◽  
Author(s):  
KIYOSHI IMAI ◽  
YUICHI KAWAZOE ◽  
TANEZO TAGUCHI
Keyword(s):  
Grignard Reagents ◽  
Grignard Reaction

Absolute stereochemistry of (−)-camoensine and (−)-camoensidine in Maackia species

1994 ◽  
Vol 72 (1) ◽  
pp. 214-217 ◽  
Author(s):  
Hajime Kubo ◽  
Shigeru Ohmiya ◽  
Isamu Murakoshi
Keyword(s):  
Grignard Reagents ◽  
Grignard Reaction ◽  
The Absolute ◽  
Absolute Stereochemistry

It was demonstrated that the attack of Grignard reagents such as methyl-, allyl-, and 3,3-dimethoxypropyl magnesium bromides on 11,12-dehydrocytisine occurs on the α-face, to give the corresponding 11α-alkylcytisine. (−)-Camoensine and (−)-camoensidine were synthesized from (−)-cytisine via the Grignard reaction. The absolute stereochemistry of the above alkaloids was confirmed to be 7R, 9R, 11R and 6S, 7R, 9R, 11R, respectively.

scholarly journals A versatile method for the N, N-dialkylation of aromatic amines via Grignard reactions on N,N-bis(benzotriazolylmethyl)arylamines

1990 ◽  
Vol 68 (3) ◽  
pp. 456-463 ◽  
Author(s):  
Alan R. Katritzky ◽  
Stanislaw Rachwal ◽  
Jing Wu
Keyword(s):  
Alkyl Group ◽  
Aromatic Amines ◽  
Grignard Reagents ◽  
Grignard Reaction ◽  
Aryl Ring ◽  
Alkyl Groups ◽  
Grignard Reactions ◽  
Stepwise Procedure ◽  
High Yields

Grignard reactions of N,N-bis(benzotriazolylmethyl)arylamines afford the corresponding N,N-dialkylarylamines in high yields. Electron-releasing substituents on the aryl ring facilitate the reaction. Arylamines are N,N-dialkylated with two different alkyl groups by a stepwise procedure: N-benzotriazolylmethylation of an amine followed by a Grignard reaction to introduce the first alkyl group, and repetition of the same procedure to introduce the second alkyl group. Grignard reagents derived from 1,4-dihalobutane, upon reaction with N,N-bis(benzotriazolylmethyl)arylamines, give the corresponding N-aryl-hexahydroazepines together with acyclic products. Keywords: azepine, tertiary arylamines.

scholarly journals Reduction of Bromo- and Iodo-2,6-bis(diphenylphosphanylmethyl)benzene with Magnesium and Calcium

2016 ◽  
Author(s):  
Alexander Koch ◽  
Sven Krieck ◽  
Helmar Görls ◽  
Matthias Westerhausen
Keyword(s):  
Degradation Products ◽  
Grignard Reagents ◽  
Grignard Reaction ◽  
Ether Cleavage ◽  
Degradation Processes ◽  
Coordination Sites ◽  
Subsequent Degradation

Arylmagnesium and -calcium reagents are easily accessible, however, ether degradation processes limit the storability especially of the calcium-based heavy Grignard reagents. Ortho-bound substituents with phosphanyl donor sites usually block available coordination sites and stabilize such complexes. The reaction of bromo-2,6-bis(diphenylphosphanylmethyl)benzene (1a) with magnesium in tetrahydrofuran yields [Mg{C6H3-2,6-(CH2PPh2)2}2] (2) after recrystallization from 1,2-dimethoxyethane. However, the similarly performed reduction of bromo- (1a) and iodo-2,6-bis(diphenylphosphanylmethyl)benzene (1b) with calcium leads to ether cleavage and subsequent degradation products. α-Deprotonation of THF yields 1,3-bis(diphenylphosphanylmethyl)benzene. Furthermore, the insoluble THF adducts of dimeric calcium diphenylphosphinate halides, [(thf)3Ca(X)(µ-O2PPh2)]2 [X = Br (3a), I (3b)], precipitate verifying ether decomposition and cleavage of P-C bonds. Ether adducts of calcium halides [such as [(dme)2(thf)CaBr2] (4)] form supporting the initial Grignard reaction and a subsequent Schlenk-type dismutation reaction.

Stereospecific Grignard reactions of cholesteryl 1-alkenesulfinate esters: Application of the Andersen Protocol to the preparation of non-racemic α,β-unsaturated sulfoxides

2003 ◽  
Vol 81 (6) ◽  
pp. 423-430 ◽  
Author(s):  
Rick R Strickler ◽  
John M Motto ◽  
Craig C Humber ◽  
Adrian L Schwan
Keyword(s):  
Ester Group ◽  
Grignard Reagents ◽  
Grignard Reaction ◽  
Substitution Reactions ◽  
Reaction Conditions ◽  
Enantiomerically Pure ◽  
Sulfinate Esters ◽  
Grignard Reactions

Enantiomerically enriched α,β-unsaturated sulfinate esters of (–)-cholesterol undergo stereospecific substitutions at sulfur when treated in benzene at 6°C with Grignard reagents. Sulfoxides with ees of 85–99.5% are obtained when enantiopure sulfinates are used. The substitution reactions proceed with inversion of sulfur configuration. Enantiomerically pure cholesteryl (E)-2-carbomethoxyethenesulfinate is not a suitable reactant under the Grignard reaction conditions. It is suggested that the ester group induces unwanted reactions significantly lowering both the yield and sulfur stereogenicity.Key words: sulfinate, sulfoxide, Grignard reagents, stereospecific, unsaturated.

scholarly journals Regioselective addition of Grignard reagents to tosylazafulleroid and derivatization to 1,2-disubstituted [60]fullerene

2016 ◽  
Vol 14 (29) ◽  
pp. 7103-7108 ◽  
Author(s):  
Naohiko Ikuma ◽  
Koji Nakagawa ◽  
Ken Kokubo ◽  
Takumi Oshima
Keyword(s):  
Ring Closure ◽  
Grignard Reagents ◽  
Grignard Reaction ◽  
Regioselective Addition ◽  
Bond Scission

Grignard reaction with tosylazafulleroid selectively gave tosyl aminylfullerene with the relatively rare 1,2-configuration, via [5,6] ring-closure and CN-bond scission.

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